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The British Military Surgery Pocket Book

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The British Military Surgery Pocket Book

"War is Delightful to the Inexperienced"

Inscription on the tomb of Henry III in Westminster Abbey

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© Crown Copyright 2004

This publication supersedes The Field Surgery Pocket Book 1981 (AC No 12552)

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Editor: Colonel P Roberts CBE MS FRCS Emeritus Professor of Military Surgery Royal College of Surgeons of England

Department of Military Surgery, Army Medical Directorate, Former Army Staff College, Slim Road, Camberley, Surrey GU15 4NP, UK. [email protected]

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iv Contents_etc.qxd 28/09/2004 15:54 Page v Foreword Foreword

The Field Surgery Pocket Book first appeared in 1944 and the last edition, edited by Major General Norman Kirby OBE QHS FRCS and Mr Guy Blackburn MBE MA MChir FRCS, was published in 1981. This new edition has been retitled to reflect the relevance of its content to military practitioners serving in the Royal Naval, Army and Royal Air Force Medical Services irrespective of the arena of combat. Weapons systems are becoming more 'sophisticated' and are generating different patterns of injury some of which will require new treatment protocols. However, battle trauma remains primarily a surgically-focussed specialty. Surgical capability and professional education have changed enormously since the earlier edition and the increasing emphasis on specialisation and subspecialisation is conspiring to limit the surgeon's repertoire to a single system if not a single organ. Clearly, this creates a substantial challenge for the surgeon who specialises in military surgery who, of necessity, has to be capable of entering most, if not all, body cavities and deal competently with a variety of trauma-related emergencies invariably without access to the modern diagnostic tools available in peacetime hospital practice. This book is produced primarily for the Defence Medical Services, not only for surgeons but for other doctors, nurses and military medical responders It is also of relevance to our civilian colleagues who increasingly have to manage injuries in the community which were previously confined to the battle-field.

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The book has been completely revised in both format and content to make it clinically relevant, easily understandable and always accessible. It has been skillfully edited from a vast source of contributors to whom I am personally very grateful.

Ian Jenkins CVO QHS FRCS Surgeon Vice Admiral Surgeon General

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Foreword Contents list List of Contributors Preface and Acknowledgments Introduction Abbreviations

Chapter 1 Patterns of Injury in Military Operations

Chapter 2 Pathophysiology of Ballistic, Blast and NBC Injury

Chapter 3 Battlefield Advanced Trauma Life Support

Chapter 4 Damage Control Surgery

Chapter 5 Principles of Wound Management

Chapter 6 Triage

Chapter 7 Analgesia in Forward Areas

Chapter 8 Infections, Antibiotics and Biological Weapons

Chapter 9 Limb Injuries

Chapter 10 Vascular Injury

Chapter 11 Amputation

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Chapter 13 Pelvic Injury

Chapter 14 Urological Trauma

Chapter 15 Thoracic Injury

Chapter 16 Head Injury

Chapter 17 Ophthalmic Injury

Chapter 18 Maxillofacial Injuries

Chapter 19 Injuries of the Ear, Nose and Throat (ENT)

Chapter 20 Spinal Injuries

Chapter 21 Peripheral Nerve Injuries

Chapter 22 Burns

Chapter 23 Principles of Plastic and Reconstructive Surgery

Chapter 24 Tropical Diseases

Chapter 25 Field Anaesthesia and Intensive Care

Chapter 26 Heat, Cold and Immersion Injury

Chapter 27 Military Psychiatry

Chapter 28 Major Incident Medical Management

Chapter 29 The Incident Response Team and Aeromedical Evacuation

Chapter 30 Practical Procedures

Index

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Contributors

A Allsopp PhD, Head, Applied Physiology, Institute of Naval Medicine, Gosport. N Buxton FRCS (Neurosurg) DMCC RAMC (V), Lieutenant Colonel, Consultant Neurosurgeon, The Walton Centre, Liverpool. L C Cancio MD FACS, Lieutenant Colonel, Medical Corps US Army. J C Clasper DPhil FRCS(Orth), Lieutenant Colonel, Consultant Orthopaedic Surgeon, MDHU Frimley Park Hospital, Camberley. G J Cooper OBE PhD, Team Leader (Trauma), Biomedical Sciences, Dstl Porton. T C S Cubison FRCS, Major, Specialist Registrar in Burns and Plastics, Queen Victoria Hospital, East Grinstead. A Gibbons FDA FRCS RAF (V), Wing Commander, Specialist Registrar in Oral and Maxillofacial Surgery, Craniofacial Unit, Birmingham Children's Hospital. A D Green MRCPath DTM&M, Wing Commander, Defence Consultant Advisor in Medical Microbiology, Army Medical Directorate, Camberley. M F P Griffiths FRCOphth, Colonel, Defence Consultant Advisor in Ophthalmology, MDHU, Frimley Park Hospital, Camberley. R J Guy MD FRCS, Surgeon Commander, Consultant General Surgeon, MDHU, Peterborough District General Hospital. ix Contents_etc.qxd 28/09/2004 15:54 Page x

A Hosni FRCS (ORL), Colonel, Consultant Advisor in Otolaryngology, MDHU, Frimley Park Hospital, Camberley, G D Housam CD FRCA, Consultant Anaesthetist, Defence Nuclear, Biological and Chemical Centre, Winterborne Gunner. J B Hull MD FRCS (Orth), Consultant Orthopaedic Surgeon, Frimley Park Hospital, Camberley. B C Jenner Dip IMC RCSEd QARANC, Major. Resuscitation Officer, West Kent Health Trust, Pembury. A S Jacks OstJ FRCOphth, Lieutenant Colonel, Army Consultant Advisor in Ophthalmology, Royal Centre for Defence Medicine, Birmingham. A R Kay FRCS FRCS (Plast) Lieutenant Colonel, Consultant Plastic Surgeon, Director, Burns Unit, Frenchay Hospital, Bristol. A W Kent FRCS, Lieutenant Colonel, Consultant Orthopaedic Surgeon, Royal Hospital Haslar, Gosport. L Lundberg MD PhD, Assistant Professor, Surgeon General's Department, Stockholm. P F Mahoney FRCA, Major, Consultant Anaesthetist, 16 Close Support Medical Regiment, Colchester. A D Malyon FRCS (Plast), Lieutenant Colonel, Consultant Plastics Surgeon, Royal Hospital Haslar, Gosport. J Martin MD, Colonel, Medical Corps, US Army. x Contents_etc.qxd 28/09/2004 15:54 Page xi

N McGuire FRCA, Wing Commander, Consultant Anaesthetist and Intensivist, John Radcliffe Hospital, Oxford. S G Mellor MS FRCS, Colonel, Defence Consultant Adviser and Consultant General Surgeon, MDHU, Frimley Park Hospital, Camberley. EHM Oakley MB BCh, Head of Survival and Thermal Medicine, Institute of Naval Medicine, Gosport. I Palmer MRCPsych, Lieutenant Colonel, Professor of Military Psychiatry. Royal Centre for Defence Medicine. Birmingham. A N Pandya FRCS (Plast), Squadron Leader, Consultant Plastic Surgeon, Royal Hospital Haslar, Gosport. P J Parker FIMC FRCSEd (Orth), Lieutenant Colonel, Consultant Orthopaedic Surgeon, MDHU, Friarage Hospital, Northallerton. C Pipkin FRCPath, Surgeon Commander, Consultant Advisor in Medical Microbiology, Royal Hospital Haslar, Gosport. L Pitkin MRCS MSc, Specialist Registrar in Otolaryngology, St George's Hospital, London. P Revington TD, FDS FRCS RAMC (V), Lieutenant Colonel, Consultant Oral and Maxillofacial Surgeon, Frenchay Hospital, Bristol. M J Roberts MA FRCA, Consultant in Anaesthesia and Intensive Care, University of Colorado Health Sciences Centre, USA.

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P Roberts CBE QHS MS FRCS L/RAMC Colonel, Professor of Military Surgery, DGAMS Adviser in Surgery, Army Medical Directorate, Camberley. P J Sadler FRCA, Consultant in Critical Care and Anaesthesia, Queen Alexandra Hospital, Portsmouth. G V Scerri FRCS, FRCS (Plast), Wing Commander, Consultant Plastic and Hand Surgeon, Royal Hospital Haslar, Gosport. R A H Scott FRCS, FRCS (Ophth), Wing Commander, RAF Consultant Advisor in Ophthalmology, Royal Centre for Defence Medicine, Birmingham. C L Shieff FRCS RAMC (V), Lieutenant Colonel, Consultant Neurosurgeon, Royal Free Hospital, London. M F Smith TD ChM FRCS L/RAMC (V) Colonel, Consultant Urologist, Forth Valley Acute Hospitals NHS Trust. P A Stanworth MA FRCS RAMC (V), Lieutenant Colonel, Consultant Neurosurgeon, Walsgrave Hospital, Coventry. M J Tipton PhD, Professor, Head Environmental Medicine Unit, Institute of Naval Medicine, Gosport. D J Vassallo FRCS, Lieutenant Colonel, Consultant General Surgeon, Royal Hospital Haslar, Gosport.

xii Preface and Acknowledgments xiii Contents_etc.qxd 28/09/2004 15:54 Page xiii 15:54 28/09/2004 Contents_etc.qxd Contents_etc.qxd 28/09/2004 15:54 Page xiv Preface and Acknowledgments Preface and Acknowledgments

This book has been produced to replace the current edition of Field Surgery Pocket Book (FSPB) - the British Military Medical Services' standard pocket guide to military surgery in the field since WWII and last revised in 1982. The FSPB was written for military surgeons and, to lesser extent civilian surgeons, called upon to carry out war surgery. It was regarded as both a directive on and doctrine for, surgery in the field in time of war. To this end, the FSPB has always been about the most appropriate management for war wounds, from time of wounding, through surgery to rehabilitation. Succeeding editions of FSPB have continued to reflect changes and improvements in casualty care but, at the same time, placed emphasis on the tried and trusted methods of war wound management learnt in past conflicts. Although this current book has been completely rewritten and has a new title, its aims are basically unchanged from those aspired to by the FSPB. Not least, The British Military Surgery Pocket Book continues the directive and doctrinal approach of its predecessor in terms of emphasising the basics. For surgeons to be unaware of the basics of war surgery or worse still forget them will, at best, condemn some casualties in their care to suboptimal treatment and, at worst, others to an unnecessary death. During high-intensity conflict with many casualties, the basic tenet is 'do the most for the most'. The surgical corollary of this may seem perverse. It is not about doing complex, definitive surgery for all; it is about doing the minimum necessary to save life and limb. This approach alone will benefit the majority of those injured xiv during war-fighting. Contents_etc.qxd 28/09/2004 15:54 Page xv Preface and Acknowledgments

Why was it felt necessary to change to the new title and completely revise the book's content? Since 1982, British military personnel have been increasingly involved in Operations Other Then War, (OOTW). These are low-intensity military operations providing Humanitarian aid, peace-keeping duties and peace-enforcement. Nevertheless, they incur the risk of injuries occurring to UK military personnel. They also carry the added burden of dealing with other nation's military and civilian casualties, albeit, usually small in number. Not infrequently, the local medical infrastructure in areas where OOTW are undertaken has been destroyed or is inadequate. The onus then falls on deployed military medical personnel to deal with the whole spectrum of trauma (and non-trauma) cases presenting to them. Because the environment is stable (non-hostile), casualties few in number and time-lines for casualty transferto surgery short, surgeons are faced with major injuries requiring more than 'field' surgery. The basic management principles still apply but, because casualty numbers and time allow, more complex surgery can be considered. In the same vein, follow-on surgery not normally done in an austere setting may need to be undertaken, particularly on civilians. This is one reason I have included in this book complex management and surgical procedures, not normally associated with war surgery. There are other reasons. Bomb and bullet terrorism worldwide is on the increase. Civilian surgeons in the main, deal with the victims injured by 'military' weapons but, do so in a peace-time setting with the full range of support services available to them. Further, military medicine in the field is becoming more sophisticated. Field intensive care is now the norm and relatively sophisticated modes of investigation are available, CT scanning being one example. I have attempted in this book, to reflect the needs of my civilian xv Contents_etc.qxd 28/09/2004 15:54 Page xvi

colleagues when, for some, they deal with unfamiliar injuries. Equally, I have also attempted for my military medical colleagues in all three Services, to encompass the more sophisticated approach to Operational medical care, we all aspire to. The title also reflects the tri-service approach to the provision of medical care during military operations. It is not just about the Army providing care in the field, it is about all three services’ medical services, deployed separately or on combined operations, providing care in whatever military environment they find themselves. This book is primarily for surgeons. Nevertheless, experience with the FSPB tells us that General Duties medical officers and others working alone for example, at sea and, surgeons with little experience, will look to this new PB for guidance. As editor, I have unashamedly included some very basic surgical procedures and techniques, diagnostic guidelines and first principles - for example - BATLS, in the text. This is a multi-author book. Like most British military texts, it is not author-attributed for individual chapters or parts of chapters. To all contributors who have acted as subject matter experts, including my sub-editorial colleague, I extend my sincere thanks. Without their expertise and effort, this book would not have been published. I am also indebted to the HQ Adjutant General Design Studio, who illustrated and designed the layout of this book, I extend my thanks.

P Roberts Army Medical Directorate Camberley July 2003

xvi Contents_etc.qxd 28/09/2004 15:54 Page xvii Introduction Introduction

Recognition of the value of an easily portable vade mecum for those tasked with the care of the injured on the battlefield long predates the Field Surgery Pocket Book, first published in 1944. Indeed ,the classic surgical textbooks of Ambroise Pare and Peter Low written in the 16th century dealt primarily with injuries sustained in war. Noel Chavasse, the first world war RAMC surgeon who won the VC and bar for undertaking surgery on the battlefield, wrote to his mentor, the famous orthopaedic surgeon Sir Robert Jones describing how he carried Jones' textbook in his knapsack. It is well recognised that the lessons of military surgery are easily and rapidly forgotten after conflict ceases. Ever since its initial publication, the Field Surgery Pocket Book has served to remind those confronted by the need to manage war injuries of the different techniques and priorities that may be required. My own much treasured 1962 edition reminded me of these principles when I was faced with management of the Old Bailey and Tower of London terrorist bomb explosions a decade later. This new edition, renamed The British Military Surgery Pocket Book, retains the principle, evoked in previous editions, of concentrating on practical advice and keeping theoretical information to an essential minimum whilst at the same time filling a gap in the current surgical literature. It re-emphasises those lessons that have stood the test of time such as excision and delayed primary suture of penetrating wounds. It also introduces newer concepts such as damage control surgery, tried and tested in the United States in the management of the epidemic of firearm injuries in their major cities. The chapters on intensive care and the management of psychiatric xvii Contents_etc.qxd 28/09/2004 15:54 Page xviii Introduction

and psychological problems reflect the increasing sophistication of care on the battlefield. This handbook will also be of value to civilian surgeons who sadly, because of a world wide increase in terrorism and violence, will need to manage bomb, bullet and bioterrorism injuries without warning, everywhere from large cities to idyllic tropical holiday resorts. Such surgeons with few exceptions will not have had experience in dealing with the wide spectrum of injury that follows such assaults. This book will be an essential companion to them in such times of need. The editor and contributors deserve congratulations in distilling the vast amount of knowledge that has grown exponentially since the last edition just over twenty years ago, down to an easily comprehensible and manageable level that reflects all that was best in the previous editions of the Field Surgery Pocket Book. It will be welcomed by military surgeons worldwide and also deserves dissemination throughout the emergency departments, acute wards and operating theatres of civilian hospitals. British surgical textbooks have always had a high reputation. The British Military Surgical Pocket Book is a significant addition to this body of literature.

Sir Miles Irving

DSc (Hon) MD. ChM. FRCS. FACS (Hon). FRCS Canada (Hon). FmedSci. Emeritus Professor of Surgery, University of Manchester; Civilian Consultant in Surgery to the Army; Honorary Colonel 201(Northern) Field Hospital; Chairman, Newcastle upon Tyne Hospitals NHS Trust. xviii Contents_etc.qxd 28/09/2004 15:54 Page xix Abbreviations Abbreviations

A&E Accident and Emergency Department AP Anterior-Posterior ARDS Adult Respiratory Distress Syndrome APPT Activated Partial Thromboplastin Time AXR Abdominal X-Ray BP Blood Pressure BVM Bag-Valve-Mask CRT Capillary Refill Time C&S Culture and Sensitivity CSF Cerebrospinal Fluid CT Computer-aided Tomography CXR Chest X-Ray DIC Disseminated Intravascular Coagulopathy DNA Deoxyribonucleic Acid DPL Diagnostic Peritoneal Lavage DVT Deep Vein Thrombosis ERCP Endoscopic Retrograde Cholangio-Pancreatography FAST Focused Abdominal Sonography for Trauma FBC Full Blood Count FFP Fresh Frozen Plasma GA General Anaesthesia GIT Gastro-Intestinal Tract HDU High Dependency Unit i.m. Intramuscular ITU Intensive Therapy Unit i.v. Intravenous LA Local Anaesthesia MO Medical Officer NATO North Atlantic Treaty Organisation NBC Nuclear Biological and Chemical xix Contents_etc.qxd 28/09/2004 15:54 Page xx Abbreviations NBM Nil By Mouth NG Naso-Gastric PA Posterior-Anterior OGD Oesophago-Gastro-Duodenoscopy PE Pulmonary Embolism PRE Per Rectal Examination PRV Per Vaginal Examination PT Prothrombin Time RAF Royal Air Force RBC Red Blood Cell (count) RN Royal Navy RTA Road Traffic Accident s.c. Subcutaneous U&Es Urea and Electrolytes USS Ultra Sound Scan

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Patterns of Injury in Military Operations

Introduction

0101 The Armed Services exist to conduct A military operation is anything the operations on behalf of the Nation. This covers Nation (Parliament) a spectrum of operational scenarios from those directs the military involving no combat to large scale war fighting. to carry out. In between, are smaller scale, lower intensity operations which, nevertheless, carry the risk of incurring casualties. Patterns of injury and the 'casualty template' can vary, depending upon the nature of the military operation being undertaken. A typical 'casualty template', derived from a meta analysis of major conflicts since WWI, is shown in Table 0101.

CASUALTY TEMPLATE The patterns of injury caused by fragments Abdomen 10% and bullets are Thoracic 5% generally different. Upper Limb 20% Lower Limb 35% Head/neck 12% Burns 10% Multiple 8%

Table 0101 The average distribution of wounds (%) in conventional warfare - the “casualty template”.

In the Falklands campaign of 1982, half (51%) of British casualties sustained during land battles, were caused by rifle and machine gun bullets: most of the engagements were infantry versus infantry. In contradistinction, during the Gulf War of 1991, 1 Chapter_1.qxd 28/09/2004 16:03 Page 2 1: Patterns of Injury in Military Operations

armour and artillery were extensively used, resulting in a higher proportion of casualties injured by fragments (80%), as opposed to bullets. . The different spread of regional injuries seen in these two disparate military operations and others since WWI, is illustrated in Table 0102. In the future, the use of so called "novel weapons" designed to cause thermal injury and/or primary blast injury (fuel-air and thermobaric weapons), is likely to produce new patterns of trauma, which may have implications for the provision of medical support. For example, an increased need for ventilatory support for blast and thermal lung injury, as well as intensive care in the field. In order to appreciate the unique nature of battlefield injuries, it is necessary to understand something of the aetiology of injury, the complexity and lethality of some of the wounds and the impact of time delay on outcome.

Head & Neck Thorax Abdomen Limbs Other World War I 17 4 2 70 7 World War II 4 8 4 75 9 Korean War 17 7 7 67 2 Vietnam War 14 7 5 74 Borneo 12 12 20 56 Northern Ireland 20 15 15 50 Falkland Islands 16 15 10 59 Gulf War (UK)** 6 12 11 71 (32)* Gulf War (US) 11 8 7 56 18† Afghanistan 16 12 11 61 Chechnya 24 9 4 63

* Buttock and back wounds, all multiple fragment injuries, as a separate figure. † Multiple wounds. ** 80% caused by fragments; range of hits 1-45, mean of 9.

Table 0102 Anatomical distribution of penetrating wounds as a percentage, for varioius conflicts.

2 Chapter_1.qxd 28/09/2004 16:03 Page 3 1: Patterns of Injury in Military Operations Aetiology of Injury Penetrating injuries are occasionally encountered 0102 The causes of trauma fall into four main during TTW when groups: live ammunition is used in training. • Penetrating. • Blunt. • Blast. • Thermal. In peace, or during transition to war (TTW), the majority of injuries are caused by blunt trauma (e.g., RTAs and training injuries). In war, penetrating injuries predominate, the average figure being 90% for all conflicts since WWI. Blunt trauma, including the effects of blast, together account for 8% of battlefield injuries.

Penetrating injury 0103 The magnitude and lethality of injuries Penetrating injuries sustained in war is related to: are caused by • The mechanism of injury. fragments, bullets or both. Fragments • The type of missile. may be primary or secondary. • The distribution of the injuries. • Wound location i.e., which internal organs are injured. Between 60 to 90% of penetrating injuries in war are due to primary or secondary fragments from exploding munitions; the remainder are caused by bullets. These may occur in combination with other causes of trauma e.g., blast and burns. Limb injuries predominate, with twice as many lower limb to upper limb wounds.

0104 Most modern explosive munitions are "improved" fragmentation devices, that deliver hundreds to thousands of preformed fragments 3

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Most fragment contained within the munition, or submunition such as wounds are low energy-transfer bomblets. Older devices produced random fragments injuries and derived from the weapon casing. The lethality for superficial in nature. fragmentation weapons and bullets is shown in Table 0103.

Type Lethality Random Fragmentation Device 1 in 5 (Shell) 1 in10 (Grenade) Preformed Fragmentation Device 1 in 7 (Shell) 1 in 20 (Grenade) Military Bullet 1 in 3

Table 0103 The lethality of penetrating missiles.

The mortality caused by preformed fragmentation weapons has fallen but, the hit rate has risen. This was well illustrated during the Gulf War of 1991 where, in one British Field Hospital, 81% of the received casualties had sustained fragment wounds. In this series, wound numbers per casualty ranged from 1-47 with an average of 9. This is exactly what On average, it takes four people to look improved fragmentation weapons are designed to do: after each casualty! increase surviving casualty numbers and place an additional burden on the casualty transfer chain.

0105 Fragments (and bullets) do not respect anatomical boundaries. At least 40% of casualties in conventional war will have multiple, penetrating injuries involving limbs and body cavities. This may significantly change the casualty profile with, for example, many more penetrating eye injuries (in the absence of eye protection) and more peripheral nerve and vascular injuries (approximately 2-4% of all limb wounds). Fragment injuries involving several body systems can present a diagnostic problem: which wound or combination of wounds is likely to be causing clinical deterioration? Similarly, the multiplicity of trauma implies that, in the absence of specialist teams, 4 military anaesthetists and surgeons must be capable Chapter_1.qxd 28/09/2004 16:03 Page 5 1: Patterns of Injury in Military Operations

of operating on all the body cavities, as well as Following multiple fragment injury, treating vascular injuries, soft tissue and bone injury. in approximately 0106 The lethality of military rifle and machine one third of casualties one body gun bullets has remained unchanged for the last area is involved, 100 years, with a 33% chance of being killed if hit in another third, (Table 0103). Figures derived from the “hostile action two body areas casualty system” (HACS) database, show the and in the remaining third three or more outcome for soldiers injured in Northern Ireland by areas are affected. a single rifle bullet during the period 1969 to 1979 (Table 0104). These figures also confirm the lethality of these bullets when they strike the 'critical area', (i.e. brain, mediastinum and abdomen), as opposed to the limbs.

Site of Injury Dead on Arrival Died in Hospital Survived Head (Brain) 7 1 Head (Face) 4 Neck 2 Chest 7 2 9 Thoracoabdominal1 1 Abdomen 4 5 Upper Limb 11 Lower Limb 13 TOTAL 14 8 45

Table 0104 Outcome following injury by a single rifle bullet.

0107 Missiles can produce wounds that vary from a simple laceration to one causing massive tissue It only requires destruction and disruption. Often, because of shock a single fragment with sufficient energy wave and temporary cavitation effect, there is nerve to lacerate a major and vessel damage lateral to the primary missile artery or vein, track (0206). This means wounds vary enormously or injure the brain in their complexity but, as will be seen in subsequent stem, to produce a lethal injury! Chapters, this does not imply they require complex procedures for their initial management.

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Following a blast Blunt injury in the open, the effectiveness 0108 The spectrum of blunt trauma is similar of the shock wave to that encountered in peacetime e.g., RTAs, falls, to cause injury decays rapidly blows to the head, torso and limbs. with distance. Blast injury

Traumatic 0109 Primary blast injury alone is an infrequent amputations due to cause of survivable injury on the battlefield (0221). blast are relatively common and have a For a casualty to sustain mainly primary blast injury, unique causation. e.g., bowel damage, they must be close to the point of detonation. This close proximity means the likelihood of mutilation, or fatal injury caused by fragments, is high. The effects of a blast may be compounded if it occurs in water or a confined space, resulting in a larger number of casualties or more serious injuries (0221). Those who survive a blast injury are at risk of developing blast lung. Many will require ventilation and all that that implies in terms of medical and nursing care. The more rapid the onset of respiratory symptoms, the worse the prognosis, making for a more complex and demanding clinical problem.

Thermal injury Because 0110 Thermal injury is common in certain military penetrating injury environments, e.g., on board ship and in armoured predominates, thermal and blast fighting vehicles. During the Israeli - PLO war in the injury tend to Lebanon, the incidences of burns amongst tank be forgotten. crews was 20%. During WWII burns have been calculated as affecting 40% of American tank crews (includes all grades of severity). The figures for British tank crews ranged from 17-37%. What is pertinent is that 50% are complicated by penetrating injury. Because burning in armoured fighting vehicles occurs in confined spaces, the incidence of inhalation injury is high. Many of these casualties, if they are to survive, will require ventilation and management in an HDU or ITU environment. 6

Blast Injury: see Chapter 2 Chapter_1.qxd 28/09/2004 16:03 Page 7 1: Patterns of Injury in Military Operations Lethality of War Injury It does not matter whether the cause of injury is a high 0111 The anatomical distribution of penetrating velocity rifle bullet, wounds for various conflicts, is shown in Table 0102. or a low velocity What these figures do not illustrate is the complexity fragment, what is important is the of many, and the lethality of some wounds. amount of energy During a high intensity engagement, 17-25% of those converted to actual damage injured will be Killed in Action (KIA) and die before in the tissues. reaching a surgical facility; 3-8% will subsequently Die Of Wounds (DOW).

0112 During war fighting, 90% of deaths (KIA) occur on the battlefield, the majority within 30 minutes of wounding. In these cases, injury is generally to critical areas. Further, 70% of the fatally wounded die within 5 minutes. The majority of these immediate deaths are due to through - and - through penetrating brain or brain stem injury, or damage to major vessel(s), with subsequent exsanguination (Table 0105).

Cause Percentage Exsanguination 46 80% Torso 20% Limb Brain (CNS) Injury 21 Pulmonary Injury (including airway) 5 Airway (1) Tension Pneumothorax (2) Sucking Pneumothorax (2) Mutilation (including incineration) 10 Multiple injuries 10 DOW 8 British figures for Early (4)* DOW's after the Late (4) Normandy landings show 50% died within 24 hours, *Definitions in this group vary, the majority relate to casualties who die after reaching a hospital (surgical) facility; others do not. 80% within 3 days and 95% at 7 days. Table 0105 Battlefield deaths: major groupings by cause (limb injuries vary from a single major vessel bleed to traumatic amputation of three limbs). 7 Chapter_1.qxd 28/09/2004 16:03 Page 8 1: Patterns of Injury in Military Operations

Unlike peacetime Surgery has no part in the management of practice, treatment at the point through-and-through brain injury: death is virtually of injury is subject to instantaneous. Both immediate care and early surgery, many constraints, have a significant part to play in reducing the incidence not least, of death from exsanguination. The majority of bleeding the tactical situation: continued enemy from the extremities (compressible haemorrhage) is action may deny controllable by simple measures (0330 - 0331); torso access to the trauma (non-compressible) haemorrhage that does casualties! not result in immediate death, requires early surgery if there is to be a favourable outcome.

Improving Outcome

0113 Can the figure for those killed in action be reduced? Assessment based on post mortem findings, suggest 15-20% of KIAs can be salvaged by appropriate, immediate aid including surgery. Others have suggested that 10% of battlefield fatalities resulted from errors in pre-hospital management, with 11% of these errors caused by faulty first aid. What matters is that the casualties receive timely and appropriate management. In war, time is not always on the casualty's side.

0114 Table 0106 shows the predicted outcome for 1000 untreated casualties over time. These figures are based on data derived from WWII, Vietnam and Northern Ireland. The overall mortality at 24 hours is estimated to be 36%. Given the lowest figure already quoted of 17% KIAs, versus a predicted mortality of 36% without treatment, current management protocols

Site <1 hour 1-6 hours 6 - 24 hours >24 hours Head (160) 80 13 25 25+ Thorax (190) 34 8 12 12 Abdominal (100) 28 16 16 30+ Limbs (650) 26 195

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for the spectrum of battlefield injuries save the lives of half of the casualties with potentially fatal injuries.

0115 If the principle of trying to provide peacetime standards of care for the spectrum of war injuries, is applied, the above mortatility figures are totally unacceptable. How can more lives be saved? Potential areas for improvement include: • Better combat body armour (CBA) and helmet. Their effectiveness tends to be limited by weight: heavier protective clothing reduces mobility and becomes unacceptable to the fighting soldier. Undoubtedly, CBA has reduced mortality from chest wounds and better helmets have reduced fatal brain injury caused by fragments. Further improvements in head protection can save even more lives. (see Table 0105). • Improved haemorrhage control at point of wounding. Better ways of achieving wound compression, haemostatic self-applied dressings and the use of clotting adjunct factors are examples (0330). The aim must be to reduce deaths due to exsanguination (Table 0105). • Improving casualty extraction and transfer. Removing a casualty from the battlefield or a ship is often dangerous and can involve long lines of evacuation. Irrespective of increasingly sophisticated care, if a seriously injured casualty cannot get to the surgical team or the team to the casualty, time will decide the outcome.

• Triage: in war, casualties tend to occur in peaks and troughs dictated by the intensity of the fighting. In terms of numbers, this would equate to a major civilian disaster happening several times in 24-48 hours. Appropriate triage at each echelon of care will maximise survival (0603). • Trained and experienced personne: a knowledge of the principles of resuscitation, including 9

Haemorrhage Control: see Chapter 3 Chapter_1.qxd 28/09/2004 16:03 Page 10 1: Patterns of Injury in Military Operations

It is worth hypovolaemic resuscitation for non-compressible remembering that, even if all of the haemorrhage (0333) and “damage control above are improved, surgery” are essential. In the management of the nature of many torso and complex limb injuries, attempts at time battlefield injuries consuming, complicated procedures, are often to will still dictate an unfavourable the detriment of the wounded, (and those waiting outcome. in the queue for surgery). There is no place for futile care!

10

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Pathophysiology of Ballistic, Blast and NBC Injury

Introduction

0201 Projectiles that strike the body are classed as: Terminal ballistics is a foundation, not • Non-penetrating (blunt): projectiles transfer a dictat for clinical energy to the body wall without causing management: perforation. The magnitude of the body wall treat the wound not the weapon. deflection and its peak velocity, determine how energy is transferred to internal organs. Some impacts (e.g., RTAs) produce low speed, gross deflections, resulting in injury largely due to crushing and stretching of tissues (e.g., rib fractures, liver laceration). Others produce small, high speed wall deflections (e.g., baton rounds, trauma behind body armour struck by bullets), which generate stress (pressure) waves. These propagate through tissues causing additional injuries such as pulmonary and bowel contusions. Non-penetrating impacts may also result in acceleration of a part of the body. The rapid acceleration and rotation of the head, for example, may produce serious brain injury. • Penetrating: missiles pass through the body wall and interact directly with tissues. The work done by the projectile on tissues results in contusion, laceration, bone fracture and the displacement of organs. In addition to the laceration produced directly by its passage, the projectile may also transfer energy laterally, centrifugal to its path, producing indirect trauma.

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0202 Penetrating projectiles are classified Projectiles are according to their available energy and the amount of classified by energy transferred when causing mechanical damage. available energy, not velocity. The energy • The available energy (Joules) of a projectile transferred does the 2 damage, not the is 0.5 x mass (kg) x velocity (m/s). incoming energy. Typical rifle bullets have available energies of 800-1500 Joules. • The energy transferred is the difference between the energy at entry and the energy at exit. If the projectile is retained in the body, all the available energy is converted into mechanical damage. If the projectile (or parts of it) passes through the body and emerges, it will have retained some of its pre-impact energy.

0203 Wounds may be • Low energy-transfer: mechanical damage is confined principally to the path of the projectile (direct injuries). The projectile simply cuts

High energy through tissues (e.g., knives, low energy projectiles can cause anti-personnel fragments and many pistol bullets), low energy-transfer with the depth of penetration dependent upon wounds e.g., a number of factors (tissue density, projectile a stable rifle bullet passing through the shape etc.). In practice, many of the projectiles muscle of the thigh, will be retained in the body (Figure 0201). missing bone and Functional consequences vary according to the vital structures traversed tissues. and carrying on for a further 600 metres. • High energy transfer: these are due to high energy missiles transferring much of their energy to the tissues (Figure 0202). They are characterised by mechanical injury lateral to the path of the projectile (indirect injuries). An example is a rifle bullet hitting the femur and stopping dead (Figure 0203). The bone shatters producing 12 chapter_2_ballistics.qxd 28/09/2004 15:54 Page 13 2: Ballistic, Blast and NBC Injury

0510 15 cm Fig 0201 Low energy wound: The permanent track caused by the missile is narrow. Necrotic tissue is generally confined to within 2-3cm of the line of travel. Any outlet wound is small.

secondary fragments and extensive soft tissue damage. Indirect injury may be severe, both mechanically and functionally. Whether the projectile is retained in the body depends on its shape, which tissues it encounters and whether it breaks up into pieces. In practice, wounds will span these classifications.

0204 Historically, there were two classes of weapons - pistols and rifles - with loosely distinct velocities (low hundreds and high hundreds of metres per second, respectively). Consequently, wounds

Temporary cavity

Permanent

0 5 10 15 20cm

Fig 0202 High energy wound: In addition to the permanent track, the large energy-transfer by the bullet causes a bigger temporary cavity and frequently a wider exit wound. Maximum energy-transfer occurs when the bullet is at 90 degrees of yaw. 13 chapter_2_ballistics.qxd 28/09/2004 15:54 Page 14 2: Ballistic, Blast and NBC Injury

Fig 0203 The effect of a missile hitting the femur. Bone fragments cause secondary injury. Shock waves may damage tissue remote from the path of the missile.

High velocity were described in terms of the projectile's pre-impact weapons e.g., velocity - i.e., low or high. This classification is no rifle bullets, do not longer appropriate e.g., an anti-personnel fragment always cause severe may have a velocity greater than a rifle bullet but, wounds. Conversely, low velocity weapons because of its small mass (< 1g) and consequently e.g., hand guns and limited energy, is unlikely to cause the same degree fragments can of mechanical damage, (tens of Joules compared to be fatal. thousands of Joules).

0205 Injury can be classified as mechanical and functional: 14 chapter_2_ballistics.qxd 28/09/2004 15:54 Page 15 2: Ballistic, Blast and NBC Injury

Do not confuse mechanical and functional injury; small holes in the wrong place may produce serious functional injury.

Fig 0204 Missiles can cause multiple injuries along their course.

• Mechanical: the damage done to tissues, expressed solely in terms of gross and microscopic disruption. • Functional: the physiological and clinical consequences of the mechanical damage. A small hole in bowel caused by an anti-personnel fragment may be classed as minor mechanical damage, but with serious functional consequences (peritonitis). Conversely, a large superficial soft tissue injury may be gross mechanical trauma, but will (generally) not be classed as a serious, life-threatening functional injury. Always consider the likely direction of travel of the missile and the possible organs involved (Figure 0204), but, do not use this as an absolute predictor for organ damage.

Transfer of Energy to the Body

0206 Missile injury may be direct and indirect. Mechanisms producing indirect damage away from the track are:

• Stress (pressure) waves: The passage of a bullet 15

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Long bones through tissue will generate a pressure wave can be broken by high energy-transfer (it is not a true shock wave), which, depending projectiles passing on the density and the characteristics of the close to them. Direct tissue, can cause mechanical damage. It is an impact of compact infrequent cause of significant injury but may be bone will lead to comminution, break implicated in, for example, a long bone fracture. up of the projectile • Break-up of the projectile leading to multiple and motion of secondary wounds tracks and damage away from the body bone fragments. of the projectile. • Temporary cavitation.

The temporary cavity 0207 Temporary cavitation is a transient, low pressure cavity formed around the track of the projectile, which stretches the surrounding tissues (Figure 0202). It is (arguably) the principal cause of indirect injury from penetrating projectiles. Transfer of energy from the projectile causes acceleration of the tissues away from the track. This leads to the formation of a temporary cavity, with a peak volume occurring about 3 milliseconds after passage of the projectile i.e., many high energy-transfer bullets will have exited the body before the peak cavity volume is attained.

0208 The key features of a temporary cavity are: • Size. • Shape. • Contamination. • Clinical consequences.

Size: It must not be 0209 The magnitude of the cavity is largely assumed that all tissue affected dependent upon the energy transferred. Temporary by the cavity is cavitation is not an "all or none" phenomenon. damaged by it. Low energy-transfer projectiles (e.g., anti-personnel 16 chapter_2_ballistics.qxd 28/09/2004 15:54 Page 17 2: Ballistic, Blast and NBC Injury

fragments) will produce a small cavity that has little mechanical or clinical significance. If energy transfer is increased, cavity volume will increase and may be capable of causing gross tissue injury, or less obvious neurovascular and cellular damage.

Shape: 0210 Projectiles do not distribute energy uniformly along the wound track, therefore, the Most small temporary cavity is not a uniform, longitudinal shape. anti-personnel There are differences between temporary cavities fragments produce low energy-transfer caused by fragments and bullets arising from their wounds with injury available energy and shape. principally confined to the wound track; • Fragments: modern anti-personnel fragments they are usually tend to be uniform in shape (some are spheres) retained in the body. i.e., yawing may occur but usually has little effect

on the missile's presented area and hence High energy retardation. Because retardation is greatest fragments tend to when the velocity is high, namely at the point deposit most energy of entry, fragments tend to deposit most energy in the proximal part of the wound track; (Joules/cm) in the proximal part of the track, bullets deposit most followed by a fairly steady decline as they energy when they penetrate. The temporary cavity matches the yaw (tumble), energy transfer i.e., is largest close to the entry and this may be some distance into point. Because most fragments tend to be the track. retained in the body, the nature of the wound depends on the available energy . Low energy-transfer fragments tend to produce small entry points, travel a short distance (typically a few centimetres), produce limited cavitation and cause limited damage (Figure 0201). By comparison, a high-energy fragment (e.g., a large piece of weapon casing or bomb splinter) may result in a gaping wound. • Bullets: are long and pointed; they are designed to be stable in air but not in tissues. On entering the body nose-on a bullet tends to rotate around a transverse pivot (yawing) through their centre, markedly changing the presented area. 17 chapter_2_ballistics.qxd 28/09/2004 15:54 Page 18 2: Ballistic, Blast and NBC Injury

High available This rotation increases the retarding forces energy projectiles slowing the projectile down and, in doing so, (such as rifle bullets) transfers energy. When it has reached 90 usually produce high-energy degrees of rotation, retardation, energy transfer transfer wounds and cavity diameter, are at a maximum. Energy with injury also transfer declines as the bullet continues 180 present away from degrees and, if the wound track is long enough, the wound track; this is frequently the 270 degrees. Thus, if plotted in Joules/cm along case if the wound the wound track, initially the energy transfer is track is long. low, increases to maximum at 90 degrees, then declines as the presented area of the bullet and its available energy decline (Figure 0205). The shape of the temporary cavity matches the energy transfer. With high energy bullets, more energy is deposited deep within the wound track, than close to the entry point. Typically, the entry site is a small hole (Figure 0202); the exit wound is usually (but not always) much larger, in between, are likely to lie severely damaged internal organs.

Contamination 0211 All military wounds are contaminated. In general, fragment wounds are more severely contaminated than bullet wounds. • Bullets: the formation of a temporary, sub-atmospheric pressure cavity following a high

100

80

60

40

20 Energy deposit (JEnergy /cm)

0 0 5 101520253035 Penetration (cm) 18 Fig 0205 Typical energy transfer of a 5.56mm bullet in gelatine.

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energy-transfer wound, sucks contaminants into All wounds are the track and fascial planes, principally (but not contaminated. exclusively) from the exit wound. Large pieces Contaminants from anti-personnel of clothing may be thrust down tissue planes fragments are during the cavitation process and retained when confined to the the cavity collapses. Because the bullet is pointed, track; with very little material is cut and transferred from high energy-transfer wounds, the entry site. Low energy-transfer bullets that the contaminants produce small cavities and may be retained in are widely distributed the body (i.e. no exit wound) generally result in within the wound and limited contamination in fascial planes. Fragment wounds • Fragments: fragments contaminate wounds are usually more severely by cutting clothing and skin at the entry point contaminated and transferring the material along the track. than bullet wounds. With small anti-personnel fragments, plaques of clothing may be found associated with the It is in skeletal fragment and fibres may be strewn along the muscle wounds track. Large low energy fragments may cut that the axiom pieces of clothing the same size as the "treat the wound not fragment; material is frequently found wrapped the weapon" is the most appropriate. around the missile. High energy fragments It is in this tissue (which are inevitably also large) tend to shred that inappropriate large pieces of clothing and skin into small wound excision pieces and scatter these throughout the (too much, too little) typically occurs. temporary cavity and along the track. These are severely contaminated wounds.

Clinical consequences of the cavity 0212 This depends on the mechanical properties and function of the affected tissue. The cavity stretches tissue rapidly; it may also cause laceration if its elastic properties are exceeded. • Friable: in the brain or organs enclosed within a capsule the cavity may disrupt the covering leading to gross disruption of the friable interior, e.g., • Head: high energy-transfer to the cranium will result in a temporary cavity and intense 19

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stress waves that will shatter the vault and grossly disrupt the brain. The probability of death is very high. • Liver and other dense, friable organs: the cavity will lead to severe disruption and haemorrhage with a high probability of death. • Elastic: in tissues that are capable of withstanding some degree of stretch by the cavity (principally, skeletal muscle), damage may be minimal. The discrimination of viable and non-viable tissue (0503) around the wound track may be difficult. • Indirect: the formation of a large temporary cavity near a long bone may result in fracture without direct interaction. The mechanism is likely to result from a combination of the bending strain on the bone by the cavity, and strain induced by the transfer of a stress wave into the bone. High energy-transfer projectiles passing close to the spine may also affect the spinal cord. Similarly, intimal damage to arteries can occur without external damage being evident (1005).

Compounding factors 0213 Changes in presented area: in a bullet this may be due to yawing or splaying of the nose on contact with tissues. Splaying is usually achieved by removing the jacket from the front of the bullet, to expose the lead/steel core. These unjacketed bullets are prohibited for military use, but they could be employed by police forces or by civilian malevolents. The high retardation forces on such a bullet will lead to high energy-transfer (and hence serious tissue damage) in the more superficial parts of the body. Penetration is limited. The aim is to transfer the total available energy of the bullet into 20 the target.

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0214 High yaw: this may occur from: • Prior impact or interaction with materials Within a short (e.g., twigs may induce a bullet to tumble in flight). distance in tissue yawing will increase. • Assault at close range: a rifle bullet does not This "neck" varies between bullet become stable until about 50 m from the barrel. calibres - the neck At short range, the bullet may strike with "high" for a 7.62 mm bullet yaw (only a few degrees, but sufficient to is longer than that escalate the energy transfer). When the bullet of a 5.56 mm. enters tissue, it begins its yaw cycle immediately and deposits high energy early in the wound track - there is no "neck".

0215 Tissue properties: the tissues of the body have different densities and mechanical properties e.g., • Compact bone is stiff and relatively brittle. A small, low energy fragment may produce a simple fracture in a long bone. As the available energy is increased, a projectile may suffer severe retardation leading to: • High energy-transfer with severe comminution of the bone, a large bony defect and damage by the resultant cavity to the surrounding soft tissues. (Figure 0203). • Acceleration of bone fragments to become secondary missiles leading to laceration of soft tissues e.g., blood vessels. • Disruption of the jacket of the bullet leading to break-up or extrusion of components, higher energy-transfer and generation of metallic, secondary fragments. • Lung has low density and is elastic. Bullet wounds The retardation forces on projectiles are low. to the thorax Small, low energy fragments, penetrate easily involving lung and damage is confined exclusively to the track parenchyma alone, of the fragment. High available energy projectiles do very well. are similarly, poorly retarded and may transfer 21

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little energy, leading to low energy-transfer wounds. Even when the energy produces a cavity, the elastic nature of the lung parenchyma limits its effect.

0216 Fragmentation. In military bullets, this may occur due to: • Inappropriate design: the rear of the bullet may be vulnerable to distortion of the jacket and extrusion of lead. • Wounds at short range: high forces on the bullet during the early yaw may lead to distortion, lead extrusion or even break-up. • Interaction with dense bone. • Prior impact with materials: this may erode or disrupt the nose, thereby removing or weakening the jacket causing splaying on impact.

0217 Wound track length. Energy transfer is dependent on track length. Stable, intact high available energy projectiles striking tissue require a considerable track length to deposit all their energy (Figure 0205). Wound tracks in the human body can range from 1-2 cm to >40-50 cm in length. Thus: • In short wounds (e.g., hand, foot, arm): the projectile will not have sufficient track length to enter its yaw cycle; energy transfer is sometimes limited. Bone may complicate the issue, particularly in the upper arm. The relatively "soft", mobile bones of the foot and hand, may not exert a notable effect on energy transfer. • In medium wounds (e.g., soft tissue of thigh) a bullet with a track length of 20 cm will be well into its yaw cycle and is likely to exit the tissues with high yaw, causing high energy-transfer, a big cavity and a large exit wound. Interaction with bone will accentuate this. 22 chapter_2_ballistics.qxd 28/09/2004 15:54 Page 23 2: Ballistic, Blast and NBC Injury

Fig 0206 Passage of a missile through tissue may alter course e.g., hitting bone. The position of the casualty at the time of wounding may be very different when examined from that on a stretcher.

• In long wounds (e.g., abdomen) a lengthy wound track may enable the bullet to undergo yaw The small entry and small exit wound through 90, 180 and 270 degrees, thereby may suggest that a losing a large proportion of its available energy. low energy-transfer The exit (if there is one) may be a small hole, wound has occurred, an example being a low energy-transfer defect whereas, in fact, substantial internal in the abdominal wall from a nearly "spent" damage exists projectile (masking significant intra-abdominal between these carnage!). It is also worth noting that with long points. track lengths, the motion of the bullet around its longitudinal axis and interaction with different tissue planes, may lead to a swerving of the bullet away from the projected wound track (Figure 0206).

Blast

Classification 0218 Blast injury may be classified as in Table 0201: 1. Primary blast injury (PBI): caused by a sudden overpressure (shock wave) generated 23 chapter_2_ballistics.qxd 28/09/2004 15:54 Page 24 2: Ballistic, Blast and NBC Injury

Dynamic Propelled missile overpressure fragments and debris (Blastwind)

Shock wave

Fig 0207 Effects of blast.

Blast injury Cause of injury Main organs affected type PRIMARY Direct impact on the Gas-filled structures: ears, tissues of overpressure paranasal sinuses, lungs, (shock wave) gastrointestinal tract SECONDARY Primary and secondary Head, torso and limb missiles energised by penetrating and the blast non-penetrating trauma, damage to solid organs TERTIARY Physical displacement Head and neck injury, of the body by the limb fractures, traumatic blast wind amputation. Damage to the central nervous system, great vessels and solid organs QUARTERNARY Miscellaneous noxious Lungs, skin effects incidental to blast e.g., dust, fires and hot gases

24 Table 0201 Classification of blast injuries and principal organs affected. chapter_2_ballistics.qxd 28/09/2004 15:54 Page 25 2: Ballistic, Blast and NBC Injury

by the explosion (Figure 0207). Gas containing structures are predominantly affected, particularly the ear (e.g., ruptured eardrum), paranasal sinuses, lungs (e.g., contusion) and gastrointestinal tract (e.g., haemorrhage, rupture). 2. Secondary blast injury: due to primary and secondary fragments (e.g., glass, masonry) causing penetrating and non-penetrating trauma (Figure 0207). Energised fragments are the most frequent cause of injury after a blast. Collapse of buildings may produce additional trauma. 3. Tertiary blast injury: due to victim displacement by the movement of air (blast wave or wind) and collision with nearby objects producing blunt and/or penetrating trauma (Figure 0207). This mechanism accounts for the high incidence of head and neck injuries and fractures, seen following most bomb explosions. The force may be sufficient to cause limb amputation. 4. Quaternary (miscellaneous) blast injury: due to flash burns, burns from combustion of the surroundings, inhalation of noxious gases (especially carbon monoxide) and psychological effects.

Mechanisms of primary blast injury 0219 The blast shock wave. When an explosive detonates in air, an intense, rapidly expanding shock wave is generated, producing an almost instantaneous increase in air pressure. The incident pressure is the pressure perpendicular to the direction of travel of the shock wave; its magnitude is inversely related to the cube of the distance from the source. In the open, the effectiveness of the shock wave to cause injury, decays rapidly. Simple blast waves are characterised by a pressure rise to a maximum peak overpressure (A in Figure 0208). Pressure then 25

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Underwater, declines exponentially (B in Figure 0208) to a reflections occur negative sub-atmospheric pressure (suction wave) from the (C in Figure 0208) lasting up to ten times longer than under-surface the positive phase. Sub-atmospheric pressure effects and seabed. Because there is are seen when glass splinters from windows are slower blast wave accelerated backwards towards the blast source. decay and more efficient propagation Injurious effects of the shock wave depend of shock waves, predominantly upon peak overpressure and duration injury may of the positive phase. Blast waves are capable of be enhanced, flowing over and around obstructions and may affect particularly to the intestines. military personnel sheltering behind defences, particularly if there is reflection of the wave (e.g., a sheltered gun emplacement). In confined areas or under water, complex blast waves occur characterised by multiple overpressure peaks e.g., a person standing near a wall or in a confined space facing an explosion will be exposed to both incident and reflected pressures, resulting in a very significant increase in overpressure.

0220 Acoustic coupling. The initiating mechanism of primary damage by the blast wave is the rapid inward motion (acceleration) of the body wall. Energy is then propagated through tissues by: • Stress waves - longitudinal pressure waves. Multiple, air-tissue interfaces in lungs and gut, extract energy from the stress wave. This energy

+160 A

+120

+80 KPa B +40 C

0 -20 0 30 60 90 120 150 180 210 240 270 ms

Fig 0208 Simple blast wave in air showing 26 A) peak overpressure, B) decay and C) sub-atmospheric pressure. chapter_2_ballistics.qxd 28/09/2004 15:54 Page 27 2: Ballistic, Blast and NBC Injury

disrupts the delicate interface between alveoli and blood vessels, leading to haemorrhage. • Shear waves - transverse waves of low velocity producing gross distortion of tissues and organs. These account for mesenteric injuries, aortic rupture, some solid organ injuries and possibly, disruption between layers of the bowel wall.

Patterns of injury 0221 Many casualties suffer a combination of the effects summarised in Table 0201. Total body disruption normally only occurs if they are carrying the explosive device or are in very close proximity. Traumatic amputations are relatively common (e.g., standing on a land mine) and have a unique cause: a stress wave coupled into the limbs fractures a long bone (frequently the tibia), the blast wave then carries the limb away. Contamination is forced up the tissue planes. Those who survive primary blast injury are at risk of developing blast lung and many will require intermittent positive pressure ventilation. The immediate environment in which an explosion Fuel-air and occurs influences the pattern of injuries. This may thermobaric allow prediction of the consequences. For example, weapons are likely a bomb detonated in a bus will tend to inflict a high to increase the proportion of primary blast injuries on the occupants; number of casualties with combined blast detonation in a building will tend to produce more and burn injuries. secondary and tertiary effects. In addition, fuel-air explosives are designed to disable troops by pure primary blast effects on a massive scale.

Blast protection 0222 Conventional textile armours do not prevent injury from primary blast effects. Employing a foam layer which reduces energy transfer faced with a dense material such as resin-bonded aramid, can provide protection.

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Nuclear reaction 0223 Nuclear explosions result from The effects of a nuclear explosion • The break up of large, unstable nuclei into multiple depend on the smaller and more stable nuclei (e.g,. isotopes of energy of the plutonium and uranium). Once initiated, the energy weapon and the produced causes adjacent, unstable isotopes to distance from its epicentre decay (chain reaction). This fission reaction was (Figure 0209). used in the original nuclear weapons and is employed in peace for power generation. • In fusion weapons, isotopes of hydrogen are fused to form heavier helium, a process that requires intense heat. Once initiated (e.g., detonation of a fission weapon within fusion material), the energy produced is greater than that of a fission reaction.

Effects of nuclear explosion 0224 A nuclear explosion causes injury by three mechanisms: radiation, blast and thermal burns. Their relative energies in a standard nuclear weapon are shown in Figure 0210. Radiation enhanced nuclear devices, designed to deliver a fatal radiation dose to fighting troops, but less damage to property, may be used as tactical weapons.

Sensitivity to • Radiation exposure. This is usually due to radiation exposure neutron and gamma radiation. In the early varies greatly, stages, primary radiation injury is confined to making prediction of outcome difficult. a distance of 1-2km from the epicentre of the explosion and can kill. The rising fire ball causes an updraft of radioactive debris (mushroom cloud), which is subsequently deposited over a large area. The greatest risk is from large nuclear particles, which fall to earth within the first 48 hours close to the epicentre of the blast. (Figure 0209) 28 chapter_2_ballistics.qxd 28/09/2004 15:54 Page 29 2: Ballistic, Blast and NBC Injury

Lighter particles travel further

Heavy particles fall first

Updraft of radioactive debris

Heat and blast

Initial Blast Energy Radiation Blast Injury Burns 1 MT 2.2 km 4.5 km 14 km 100 KT 1.7 km 2 km 6 km 10 KT 1 km 1 km 1 km 1KT 0.7 km 0.5 km 0.5 km

Fig 0209 Rings of nuclear destruction. For the given distance, each of the three causes of injury carry a 50% mortality.

• Blast. The effects are similar to conventional exposure but more intense (0218). • Thermal burns. The intense thermal energy initially causes damage over a much wider area than blast and radiation (Figure 0209) and accounts for the majority of early injuries and death after a nuclear explosion. The light flash associated with a nuclear detonation, can result in blindness. This is usually temporary, lasting from seconds to 30 minutes. Personnel may suffer damage confined to exposed areas. Combustion of clothing and adjacent material can cause deep burns. 29

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Blast energy

Initial radiation Thermal energy Fallout

0210 Typical energy associated with a nuclear explosion.

Clinical features 0225 Most casualties will have a combination of injuries: • Burns. Because of its short duration and the skin's resistance to thermal injury, burns amongst survivors often appear serious but are, in reality, confined to the epidermis and superficial dermis and heal well (treatment 2212). Rarely, severe local burns develop within hours of a casualty being in contact with gamma radiation emmitting material. • Blunt (0201) and blast trauma (0218). • Radiation. Ionizing radiation affects cell structure, in particular DNA. Rapidly dividing cells (e.g., bone marrow, bowel, skin), are affected before the cardiovascular and nervous systems. Symptoms range from nausea, anorexia and malaise, through to vomiting, diarrhoea, skin erythema, confusion and collapse. Significant exposure is suggested by earlier onset of clinical features. Treatment is supportive (resuscitation, antibiotics, etc,). If the casualty survives, there 30 may be cycles of recovery and deterioration as

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the body attempts to repair itself. Depending on the dose received, these phases of radiation sickness can last several days/weeks, or be as short as a few hours. A longterm complication occuring in a small, unpredictable proportion of casualties, is an increased risk of cancer.

Biological Agents

0226 Likely biological agents and their management are discussed in Paragraphs 0838 through to 0841.

Chemical Agents

Introduction With appropriate 0227 Chemical agents come in the form of equipment and training, it is possible solids, liquids and gases. They are relatively easy to both survive and to manufacture and deliver using, for example, shells, provide medical care rockets, bombs and sprays. In addition to physical in a chemical incapacity and death, effects also include environment. physiological disturbances which place increased demands on medical resources. There are four main groups of chemical agent in common use: 1. Nerve agents 2. Cyanide 3. Blister agents 4. Oedemagens Nerve agents and cyanide are the most dangerous and can cause death within minutes. Correct identification ('Quick Look' Figure 0301) and treatment, are essential. Useful information includes: • To determine possible exposure: is there evidence of aircraft or artillery bombardment; spray, droplets, smoke or unusual smells? Was the casualty wearing individual protection 31 chapter_2_ballistics.qxd 28/09/2004 15:54 Page 32 2: Ballistic, Blast and NBC Injury

Military personnel equipment (IPE 0228)? Were others affected? who suddenly become a casualty Did detection equipment respond positively? without being • To identify the agent(s): symptoms, speed of wounded, or who are suffering a onset and effect of donning a respirator and use greater degree of Combopens (0235)? of incapacitation than is compatible • To assess degree of exposure: was the with their wounds, casualty under cover or exposed, exercising should be or at rest? Time lapse between exposure and considered a possible chemical decontamination? casualty. Single chemical casualties Protection are unlikely on the battlefield. 0228 Everyday clothing provides little protection; rubber and polythene are more resistant. Charcoal-embedded, liquid repellent NBC suits, Webbing and surrounding gloves and respirator (IPE), provide complete materials may protection against liquid and vapour agents for at present a hazard least six hours. Suits and gloves should be changed from 'off-gassing'. towards the end of this period (NB: following cyanide poisoning, change the respirator cannister after 20 minutes). Leather boots will be slowly penetrated; this can be prevented by the use of overboots. IPE is unpleasant to work in, is hot, bulky and impairs vision and hearing; prolonged use can cause heat illness.

Detection 0229 Chemical weapons can be detected by reagents that induce a colour change and by

32 Table 0202 Chemical agents and methods used for their detection.

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methods that detect the in vitro inhibition of the enzyme cholinesterase or, the presence of ionized agents. In liquid form, agents react with: • One Colour Detector Paper (turns blue in the presence of all liquid nerve and blister agents). • Three Colour Detector Paper (Table 0202).

Vapour may be detected by Man Portable Chemical Agent • Nerve Agent Inhibited Enzyme and Alarm Detector (MCAD): Detector (NAIAD) system. this is due to replace NAIAD in the near • Chemical Agent Monitor (CAM). In 'G' mode, future. It can detect CAM picks up and quantifies nerve agents; nerve, blister and in 'H' mode, it detects mustard vapour choking agents, (NB: it will not function at low temperatures). cyanides and some toxic industrial The main disadvantage of CAM is that it takes chemicals. approximately 6 minutes to monitor a single casualty and confirm no exposure. • Residual Vapour Detector (RVD).

Decontamination 0230 Start decontamination under shelter. Unless the casualty's condition is life-threatening, decontamination should take place before treatment. Carers must wear full IPE. • Removal of the casualties clothing will eliminate up to 90% of contamination (NB: deposit clothing in gas proof bags). • Scrub exposed skin, respirator and cuffs of gloves with 0.5% hypochlorite solution combined with a wetting agent (e.g., household detergent). Dabbing or rubbing with large quantities of Fuller's earth to absorb adherent liquid agents, can result in poisonous 'snowdrift'. • Irrigate eyes with normal saline. • Iif you have nothing else available, brush off adherent liquid (e.g., using a tree branch) and 33

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irrigate with copious amounts of water (nerve agents are not water soluble). • If casualty protection equipment (CPE) is available, remove the caualty's respirator and place the decontaminated victim within the bag. CPE consists of a sleeping bag with a clear patch over the face; it is supplied by pump-filtered air. • If buildings or equipment are contaminated, it is safer to use IPE, rather than attempt large scale decontamination.

Management of contaminated wounds 0231 This is discussed in 0503. Drop potentially contaminated fragments and wound debris into bleach to prevent “off-gassing”.

Nerve agents

Pathophysiology 0232 Most nerve agents are liquid With small doses, typical symptoms organophosphorous esters which appear colourless are: pinpoint pupils, or pale yellow. They are usually known by code runny nose and letters e.g., GA (Tabun), GB (Sarin), GD (Soman) chest tightness. and VX. Depending on formulation, they can be With larger doses, irregular and persistent liquids (especially V agents) or rapidly shallow breathing, vapourising gases. Nerve agents quickly penetrate bradycardia, mucous membranes and, in vapour form, are convulsions and absorbed by the respiratory tract and cornea. death follow these symptoms. Both liquid and vapour forms can enter via the skin (NB: symptoms may take several hours to develop). Once absorbed, nerve agents inhibit the enzyme acetylcholinesterase, resulting in an accumulation of acetylcholine at neural junctions and unabated stimulation of cholinergic receptors triggering a cholinergic crisis.

34 chapter_2_ballistics.qxd 28/09/2004 15:54 Page 35 2: Ballistic, Blast and NBC Injury Clinical features 0233 Features of cholinergic crisis include It can be (Figure 0301): difficult sometimes to differentiate • Pupils: pinpoint. between chemical weapon injury and • Respiration: bronchoconstriction, mental incapacitation wheezing, rapid shallow breathing. - see Chapter 27. • Secretions: excessive bronchial secretions, excessive salivation. • Skin: sweaty, cyanosed, underlying muscle fasciculation. • Brain: anxiety, depression of cerebral function, convulsions, loss of consciousness. • Heart rate: bradycardia or tachycardia. • Gut: vomiting, abdominal colic, involuntary defaecation and micturition. Death can occur in minutes and is usually from asphyxia secondary to bronchoconstriction, excessive secretions in the lungs, paralysis of respiratory muscles and failure of the respiratory centre in the brain.

Protection from the effects of nerve agent poisoning During the Gulf War 0234 Pretreatment with oral pyridostigmine, of 1990-91, 30mg eight hourly (Nerve Agent Pre-treatment Set approximately 1% of military personnel - NAPS tablets), protects a proportion of peripheral had to stop taking nerve cholinesterase. Start before any likely attack. NAPS tablets due to Side effects can include abdominal colic and side effects. urinary frequency.

0235 If symptoms of nerve agent poisoning are experienced, inject a Combopen (atropine 2mg, pralidoxime 500mg, avizafone 10mg) through clothing into the lateral thigh. Avizafone converts to the equivalent of diazepam 5mg. Injections can be repeated every 15 minutes up to three times. 35 chapter_2_ballistics.qxd 28/09/2004 15:54 Page 36 2: Ballistic, Blast and NBC Injury Treatment 0236 The CAM in 'G' mode is used to detect the presence of nerve agent on casualties. Start decontamination once under shelter (0230). • Suck out secretions or allow postural drainage; give oxygen. Depending on casualty numbers, ventilation (BVM or intubation) may be appropriate. Bronchospasm and excessive secretions can make this difficult. NB: avoid mouth to mouth contact! • Give i.v. • Atropine 2mg every 3-5 minutes (up to 200mg) until there is evidence of effect (pulse >90, drying of secretions, improved ease of ventilation). NB: do not use pupil size to monitor response. • Pralidoxime 500mg slowly (maximum, including Combopens, 3.5 g in 24 hours). • Diazepam 5mg as needed for convulsions. • Continue treatment e.g., atropine i.v., post-operatve respiratory support. The function of the respiratory centre and muscle power can return within 3-4 hours. Complete clinical recovery from acute effects may take several days.

0237 Atropine poisoning. This usually arrises from misuse of Combopens. Features include: • Mental changes: confusion, euphoria, hallucination, anxiety, restlessness, excitement and delirium, coma and depression of respiration. • Tachycardia. • Dry mouth. • Pyrexia.

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Tolerance to nerve agent • Failure to sweat (can result in heat illness). poisoning • Urinary retention. does not develop. Treatment is sedation with bolus doses of diazepam 2mg i.v., titrated against response (or use physostigmine).

Potential interactions 0238 Casualties who have suffered nerve agent poisoning and also need surgery, may have been given a cocktail of drugs before operation (e.g., pyridostigmine/nerve agent/muscle relaxants/atropine). This is usually of little consequence and should not prevent or delay surgery. The main problem is likely to be delayed reversal of anaesthesia requiring prolonged ventilation. NB: make sure the casualty continues to be well atropinised (0236).

Cyanide

Pathophysiology 0239 Hydrogen cyanide (prussic acid) is a gas at room temperature, making lethal concentrations difficult to obtain in the field (i.e., it is a non-persistant agent). It is colourless, smells of bitter almonds and can be experienced at sublethal levels. Detection of attack concentrations is by using NAIAD (0229). Cyanogen chloride and cyanogen bromide are the preferred forms, because they are heavy vapours. Once absorbed through the lung, they are both converted to hydrogen cyanide. The cyanide ion forms a reversible complex with the respiratory cytochrome oxidase enzyme system, resulting in impairment of cellular oxygen ultilisation. Detoxicification in the body is by conversion to harmless thiocyanate, a reaction catalysed by 37 chapter_2_ballistics.qxd 28/09/2004 15:54 Page 38 2: Ballistic, Blast and NBC Injury

intracellular trans-sulphurase enzymes, one of which requires thiosulphate as a substrate.

Clinical features 0240 The respiratory centre is particularly susceptible to cyanide, this leads to respiratory failure. A few breaths of concentrated hydrogen cyanide initially cause respiratory stimulation (the victim may be forced to take a breath whilst donning a respirator), followed by slow, deep breathing and convulsions. Cessation of respiration may occur within one minute. Nevertheless, blood remains well oxygenated and the skin is often pink (Figure 0301). With lesser exposure, there may be weakness, headache, nausea, dizziness, convulsions and coma lasting several hours. In addition, cyanogen chloride and bromide cause irritation of the eyes and upper airway, with tightness of the chest, coughing, choking and dyspnoea.

Treatment 0241 The treatment team is usually safe once the casualty is stripped. • Administer oxygen. Depending on casualty numbers, ventilation (BVM or intubation), may be appropriate (NB: avoid mouth to mouth contact). • Give slow injections i.v. of sodium nitrite 300mg and sodium thiosulphate 12.5g. This treatment may be repeated once only after 30 minutes. • Post-treatment metabolic acidosis may cause vomitting; if this happens, delay surgery and transfer where possible.

38

Management of Heat Illness: see Chapter 26 chapter_2_ballistics.qxd 28/09/2004 15:54 Page 39 2: Ballistic, Blast and NBC Injury Blister (vesicant) agents

Pathophysiology 0242 Blister agents are powerful alkylating agents, varying in colour from clear to brown. Their oily nature and absorption by surrounding material (e.g., wood, leather, rubber, paint), pose a persistant hazard. Both liquid and vapour damage eyes and skin (especially moist areas). Following exposure, irreversible tissue binding takes place within 3-5 minutes. Blister agents are primarily intended to produce casualties and reduce fighting efficiency, rather than kill. In the longer term they produce cytostatic, mutagenic and cytotoxic effects. Haemopoietic and gastrointestinal cells are particularly affected. The two main agent groups are: • Sulphur and nitogen mustards. Sulphur mustard smells of garlic and nitogen mustard has a fishy odour. • Arsenical blister agents (e.g., Lewisite). Lewisite smells of geraniums. Arsenical blister agents are often mixed with sulphur and nitrogen mustards.

The chief difference between these groups is that Depression of sulphur and nitrogen mustards have an insidious bone marrow is onset over several hours and a cumulative effect. a late effect, Conversely, skin and eye discomfort is instantaneous unlikely to be seen in the field. This following exposure to arsenical blister agents. results in anaemia, Systemic arsenical poisoning may follow exposure to neutropenia, Lewisite. Both classes of agent can be picked up thrombocytopenia using detection paper and RVD (Table 0202). and increased susceptibility to infection. Clinical features and management 0243 Liquid and vapour readily penetrate the skin and mucous membranes causing dermal injury and damage to the eyes. Inhalation results in pulmonary irritation and, if swallowed, there is delayed nausea, vomiting, diarrhoea and risk of 39 gastro intestinal perforation. chapter_2_ballistics.qxd 28/09/2004 15:54 Page 40 2: Ballistic, Blast and NBC Injury

0244 Skin: Hot, humid conditions accelerate onset and worsen the depth of injury. Moist areas are particularly affected (perineum, axillae, face and neck). With the exception of arsenical blister agents which have an immediate dermal affect, there are four clinical stages after all but the most trivial exposure: 1. Latent period lasting several hours. 2. Skin irritation, smarting, erythema. 3. Vesicle formation. 4. Necrosis. Damaged tissue is susceptible to secondary infection, ulceration and fibrosis. Healing is delayed and cutaneous scarring common.

NB Blister fluid Detection is by using CAM in 'H' mode. from Lewisite is Decontaminate the skin (0230) and treat burns hazardous conventionally. Because mustards and Lewisite - double glove and may be mixed, treat with systemic and/or local change immediately if contaminated dimercaprol (British Anti-Lewisite BAL). NB: because (2245). BAL cream chelates silver, it is not compatible with Flamazine use. Following systemic absorption, administer dimercaprol 5% (2.5mg/kg i.m.) four hourly for the first 16 hours, followed by a twice daily dose determined by the casualty's condition (NB: BAL injections are very painful). At Role 3 or 4, healing may be promoted by dermabrasion.

0245 Eyes Onset of symptoms occur approximately one hour after exposure. Features include: excessive lachrymation, burning, blepharospasm preventing eye opening, pain, severe conjunctivitis and lid swelling. There is a risk of secondary infection and temporary adherence of the eyelids. Treatment is immediate irrigation with normal saline. Administer topical antibiotics, mydriatics (dilates the pupil and paralyses 40 the ciliary muscle -Table 1702) and apply vaseline

Burns: see Chapter 22 chapter_2_ballistics.qxd 28/09/2004 15:54 Page 41 2: Ballistic, Blast and NBC Injury

(prevents adhesions). Use BAL drops after Lewisite injury. Give systemic analgesia (topical analgesia delays healing). Reassure the casualty and cover both eyes with an eye shield (1713) and refer to an ophthalmologist. NB: avoid pressure on the globe. Convalescence is often prolonged due to photophobia, lachrymation and blepharospasm, but recovery is usually complete.

0246 Respiratory effects Inhaled vapour causes inflammation followed by Carers are at risk necrosis affecting the mucous membranes of the of the cumulative whole respiratory tract. There is a triphasic response: respiratory effects of small doses • Sterile phase: several hours after exposure the e.g., bronchitis, casualty experiences a runny nose, sneezing, a pulmonary fibrosis. dry burning sensation in the throat, hoarse voice and a harsh, dry cough proceeding to bronchitis. The more rapid the onset of these symptoms, the worse the prognosis. • Secondary infection phase: results in expectoration of mucopurulent sputum. Death may occur secondary to bronchopneumonia. • Late phase: due to bone marrow depression and leucopenia (seen at Role 3 or 4). Management is nebulised oxygen, physiotherapy, sputum C&S and appropriate antibiotics. Late complications include: chronic obstructive airways disease, malignancy and sensitivity to further exposure.

Oedemagens 0247 The most important examples are phosgene and chlorine. During WWI, phosgene accounted for 85% of all chemical agent deaths. Phosgene and chlorine are rapidly vapourising liquids and consequently, do not generally pose a persistent threat (NB: pockets of gas can persist in clothing -wear IPE). Phosgene smells of new-mown hay 41

Management of Ophthalmic Injury: see Chapter 17 chapter_2_ballistics.qxd 28/09/2004 15:54 Page 42 2: Ballistic, Blast and NBC Injury

Oedemagens (there is no device available for detecting this agent), may be of military and chlorine of swimming pools. or civil origin e.g., toxic oxides Oedemagens cause increased permeability of the of nitrogen are alveolar capillaries leading to massive pulmonary contained in smoke from burning oedema. After a latent period there is coughing, buildings, ships, choking and increasing repiratory distress with aircraft or tanks. copious expectoration of frothy fluid. Treatment is rest, humidified oxygen and cough suppression (codeine phosphate 30-60mg). High dose steriods and diuretics are often tried as a last resort. Casualties frequently require assisted ventilation (0329).

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Battlefield Advanced Trauma Life Support

Introduction

0301 Managing trauma on the battlefield, is Do not become a stressful. It may be dark, dangerous, noisy, wet and casualty yourself. Make sure the scene cold. You are likely to be tired, hungry and frightened. is safe before you or Acquiring a drill will allow you to respond to casualties your team approach with life-threatening injuries with a minimum of the injured. mental effort, regardless of the environment and your own stress. What follows in this chapter is not about casualty management under fire, or other, equally dangerous situations. Casualty care in the face of enemy action may be best achieved by winning the firefight, in which you may be a participant! Then, deal with the injured. Under these circumstances, simple, life-saving first aid may be the reality. Attempting more sophisticated care may be achievable but, at the expense of your life and the lives of others. Nevertheless, in a relatively safe environment, even an austere one with limited equipment, diagnostic aids and assistance, it is possible to carry out advanced trauma life support techniques. It is incumbent upon those who provide medical care to the victims of war to have a thorough knowledge of the basic techniques that will save lives. Field medical personnel must learn to assess casualties - and the situation - using the five senses, tempered by the sixth sense - commonsense! That is what this chapter is about.

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A consistent, The first rule: prevent further injury to yourself and systematic approach the casualties! Reassure casualties that help is at is essential. hand. Get a quick history (Mechanism of injury, For every Injuries sustained, Signs and symptoms, Treatment casualty consider given - MIST). Then, consider immediate casualty the following: management in four phases: • Is the airway patent? • Primary survey Identifies life-threatening • Is the casualty problems. breathing? • Resuscitation Deals with these problems. • Is there life-threatening • Secondary blood loss? survey Top-to-toe examination. • Definitive care Specific management. The last two are likely to be carried out at a rearward echelon.

Primary Survey

0302. The primary survey is the most important phase; it is easily remembered as A B C D E Airway with (when indicated) cervical spine control. Breathing and ventilation. Circulation with haemorrhage control. Disability (Displaced brain) or neurological status. Exposure depending on environment or Evacuation.

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Airway with cervical spine control. Airway problems may be: immediate, delayed (minutes or Airway hours) or insidious 0303 Do not be distracted by other injuries; (deteriorates with time and is easily airway obstruction can quickly result in cerebral overlooked). hypoxia (3 minutes) and death (10 minutes). Talk to the casualty! A 'normal' reply indicates that the airway is patent, breathing is normal and brain perfusion adequate (NB: this can rapidly change). Failure to respond implies an altered level of consciousness with potential, or actual, airway compromise. Inappropriate or incomprehensible speech suggest onset of airway and/or breathing difficulties with reduced cerebral oxygenation. Look. Is the casualty agitated (hypoxia?), drowsy (hypercarbia?) or cyanosed? Look for evidence of facial fracture (1805) or neck injury (0307). Check the back of the mouth for blood, vomit or foreign bodies. Is there evidence of nerve agent or cyanide poisoning (Figure 0301)? Remember: • The absence of cyanosis does not mean the casualty is adequately oxygenated. • A casualty who refuses to lie quietly may be trying to sit up in an attempt to keep their airway open and/or breathing adequate. Similarly, the abusive casualty may be hypoxic rather than insubordinate or intoxicated. Listen for abnormal sounds. Snoring, stridor and gurgling are associated with partial airway obstruction. Remember: • Hoarseness implies laryngeal injury. • Total obstruction equals total silence! Feel for air movement on expiration.

45

Maxillofacial Injury: see Chapter 18 Chapter_3.qxd 28/09/2004 15:54 Page 46 3: Battlefield Advanced Trauma Life Support

NERVE AGENT CYANIDE

Pupils: Pinpoint Normal or large Skin: Sweaty, Dry, pink cyanosed, or cyanosed fasciculation Respiration: Initial respiratory Broncho- stimulation then constriction, rapid slow, deep, shallow, wheezing irregular

Secretions: Normal Excessive salivation/ bronchial secretions

Fig 0301 Chemical weapons: nerve agent and cyanide poisoning is likely to be most immediately fatal. Comparison of features identified at “quick look”. 0304 Early preventable deaths from airway problems are frequently due to: • Failure to recognise the urgent need for intervention. • Limited experience in clearing the airway. • Selecting an inappropriate airway manoeuvre. • Failure to secure the airway prior to casualty transfer. • Becoming distracted by less urgent problems.

0305 Battlefield injuries associated with airway compromise include: • Head injury with decreased level of consciousness allowing the tongue to fall back and block the hypopharynx. • Other causes of reduced consciousness (e.g., poisoning, alcohol, reduced atmospheric O2, carbon monoxide). • Maxillofacial injuries: • Displaced mid-face fractures obstructing the airway. 46 Chapter_3.qxd 28/09/2004 15:54 Page 47 3: Battlefield Advanced Trauma Life Support

• Unstable mandibular fractures Cervical spine injury occurs after ~ 4% causing tongue instability. of penetrating head • Blood, debris or mucus blocking the airway. injuries. In civilian practice, cervical • Injuries to the neck: spine injury is reported to occur • Direct trauma to the larynx in 7-15% of and supporting structures. casualties after blunt head injury. • Bleeding inside the neck compressing the hypopharynx and/or the trachea. • Burns to the face, neck and airways.

0306 A cleared airway may obstruct again if: • The casualty's level of consciousness deteriorates. • There is further bleeding or vomiting. • There is increasing swelling in or around the upper airway.

Cervical spine injury 0307 Cervical trauma is less of an issue on the battlefield; the management of life-threatening ABC injuries take priority. Nevertheless, the integrity of the cervical spine must be considered. Cervical spine injury is suspected: • In falls >5m. • Significant blunt injury above the clavicle. • Following high-energy trauma e.g., RTA, pedestrian injury, explosion. • In the unconscious casualty unable to give a history following blunt trauma. • In the casualty complaining of neck pain or loss of sensation and/or motor function in one or more limbs.

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25% of casualties 0308 Penetrating neck wounds involving the bony with chest injuries cervical spine or spinal cord, carry a 95% mortality. die unnecessarily In survivors, these wounds can be ignored in terms and 85% of these can be saved by of cervical spine protection. A combination of blunt simple care! and penetrating neck injuries should be managed as for blunt injury.

0309 Whilst moving from Airway to assessing the chest (Breathing), quickly examine the neck. An aide memoire is Twelve. Look for •Tracheal displacement. Feel with two fingers either side of the trachea in the suprasternal notch. In an advanced tension pneumothorax, the trachea is pushed away from the affected side. •Wounds. • Surgical Emphysema. This may affect the neck, face and trunk. Feel for the characteristic subcutaneous crepitus. Causes include: tension pneumothorax, tracheobronchial damage, oesophageal rupture, fractured larynx (rare), or a dislodged chest drain (commonest cause). •Laryngeal injury. •Venous distension. Consider tension pneumothorax or cardiac tamponade (NB: may be absent in hypovolaemic casualties). •Examine the neck everywhere, every time!

Breathing and ventilation 0310 Examine the following: • General: Repiratory rate, cyanosis, respiratory distress, wheezing, tachypnoea and haemoptysis. Rapid, shallow respiration is usually due to chest wall trauma, pain, air hunger or anxiety. Consider nerve agent or cyanide poisoning (Figure 0301). • Inspect: the anterior and lateral sides of the 48 chest, run your hands down the back feeling for Chapter_3.qxd 28/09/2004 15:54 Page 49 3: Battlefield Advanced Trauma Life Support

wounds, look for the presence of blood on your Wounds to the chest hands. Inspection of the back, unless urgently may be associated indicated e.g., detection of an open pneuthorax, with abdominal and spinal injuries. can wait until the secondary survey. Look for Do not forget the wounds, bruising and asymmetrical movement. abdominal cavity Signs of respiratory distress include: sitting extends up as high forward with use of accessory muscles of as the level of nipples and tips of respiration, intercostal recession, see-saw scapulae. respiration and supraclavicular and epigastric indrawing. Paradoxical movement associated with flail segments may not be obvious in a Meaningful chest muscular serviceman. examination is impossible in the • Feel: Rib fractures are suspected if there is local midst of battle, tenderness, pain on springing the chest, chest during tactical wall deformity or surgical emphysema (0309). casevac by air or Use the hands to check for wounds and in a moving vehicle! symmetrical chest movement, especially if lighting is poor. • Percuss: Hyper-resonance suggests a pneumothorax and dullness a haemothorax or lung contusion (Figure 0302). NB: All three conditions (pneumothorax, haemothorax and lung contusion) commonly coexist following major chest injuries. • Auscultate: breath sounds are absent or reduced with a pneumothorax or haemothorax. Heart sounds may be muffled in cardiac tamponade. NB: auscultation may be severely impeded by external noise!

0311 Identify or exclude the six crisis injuries (aide memoire: ATOMIC): •Airway obstruction. •Tension pneumothorax. •Open pneumothorax. •Massive haemothorax. 49

Chest Injury: see Chapter 15 Chapter_3.qxd 28/09/2004 15:54 Page 50 3: Battlefield Advanced Trauma Life Support

Aide memoire •Indented (Flail) chest. for sources of major blood loss: •Cardiac tamponade. Blood on the floor (external loss) and four more: Circulation with haemorrhage control • Chest. 0312 Shock is the general response of the body • Abdomen/Pelvis. to inadequate tissue perfusion and oxygenation. • Retroperitoneum. On the battlefield, this is usually due to bleeding or • Long bones. burns. Approximate volumes of blood lost in common injuries are shown in Figure 0303. In the young and fit, classical signs of shock do not usually appear until >30% of circulating volume is lost (Table 0301).

0313 Assess: • External bleeding. Do not forget the back; run your hands down the postero-lateral aspects of the head, trunk and limbs looking for blood and wounds. • Possible internal haemorrhage. Look for suspicious features in the: 1. Chest (0310). 2. Abdomen (1206) e.g., bruising, distension, open wounds, tenderness, guarding and rebound. NB: the abdomen is a silent reservoir for blood loss! Absence of signs does not equal absence of an intra-abdominal catastrophe! 3. Pelvis/retroperitoneum (1310) e.g., severe pain, buttock wounds, abdominal wall haematoma, deformity, pain with one pelvic compression (Figure 1302), crepitus, scrotal haematoma, meatal bleeding and bleeding PVE and/or PRE. 4. Long bones (0903) e.g., pain, swelling, wounds, deformity, loss of function, visible bone, absent pulses.

50 • Mental state. See Table 0301 Chapter_3.qxd 28/09/2004 15:54 Page 51 3: Battlefield Advanced Trauma Life Support

NB: In fit military personnel with a low resting pulse, any increase in rate due to haemorrhage may not initially, Hyper-resonant appear significant.

Dull

Fig 0302 Severe chest injury commonly causes a haemo-pneumothorax and lung compression/contusion. The percussion note is typically resonant over air and dull over blood. A chest drain should be placed so as to evacuate both.

Class of I II III IV shock Up to 750 750-1500 1500-2000 >2000 ml ml ml ml Blood loss <15% lost 15-30% lost 30-40% lost >40% lost

Heart rate <100/min >100/min 120-140/min >140/min

Systolic BP Normal Normal Decreased Decreased/ unrecordable

Pulse Normal Narrowed Narrowed Very narrow/ pressure absent

Capillary Normal Prolonged Prolonged Prolonged/ refill absent

Respiratory 14-20/min 20-30/min >30/min >35/min rate

Urine output >30 ml/hr 20-30 ml/hr 5-20 ml/hr Negligible

Cerebral Normal/ Anxious/ Anxious/ Confused/ function slightly frightened/ confused unresponsive anxious hostile

Table 0301 Classes of shock and associated clinical features. 51

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The volume of your Haemothorax fist is about 500ml up to 2.5L

500 ml

Major pelvic 250ml fracture 2-3L

1.5L

500ml will cover 2m2 1L

Fig 0303 Typical blood loss associated with common injuries.

• Colour. Hypovolaemic casualties are typically pale, cold, sweaty and cyanosed. • Presence of pulses. In the absence of a sphygmomanometer, minimum systolic BP can 52 Chapter_3.qxd 28/09/2004 15:54 Page 53 3: Battlefield Advanced Trauma Life Support

be estimated from the presence or absence of Level of consciousness palpable peripheral pulses: Radial = 90mmHg; not only reflects Femoral = 80mmHg; Carotid = 70mmHg. Absent neurological status, radial pulses (check both sides), is significant. it can be influenced by hypovolaemia • Pulse rate. A rate over 120 indicates significant with cerebral haemorrhage until proven otherwise. hypoperfusion. • Capillary refill time (CRT). Press the finger pulp for five seconds, normal colour should return within two seconds. Delay indicates impaired peripheral perfusion (NB: unreliable in cold and dark!).

Disability or neurological status 0314 This is a simple AVPU assessment of the casualty's level of consciousness and pupils (1610, 1612). Are they: Alert. Voice responsive. Pain responsive. Unresponsive?

0315 What is the approximate pupil size, are they equal and do they react to light? An abnormality suggests brain Displacement due to blood clot. Record the findings so that any change can be appreciated later.

Exposure 0316 This should be sufficient to allow assessment and treatment of life-threatening injuries. NB: total exposure may not be possible in austere surroundings; this may have to wait for a more stable environment but, do not miss life-threatening injuries.

53

Head Injury: see Chapter 16 Fig 0304The head and The second rescuer then supports Safe helmet removal requires two rescuers. neck are initially supported from above. The first rescuer removes the helmet and then takes control from the front. from above.

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Airway and cervical spine

Cervical spine 0318 In a casualty with suspected cervical spine injury (0307), inline immobilisation and airway management are carried out together. Avoid extending the neck (e.g., during chin lift). The head and neck are controlled bimanually at all times by an assistant. Remove any head gear (Figure 0304). Do not release head and neck control until injury has been excluded, or three point fixation is applied (semirigid collar, sandbags/blocks, head tape). Measuring for and applying a cervical collar, are illustrated in Figure 0305. Cervical spine control may initially have to be ignored (e.g., on the battlefield or a rescuer attempting to manage an airway single-handedly). In the combative casualty, trying to immobilise the spine may cause more harm than good; compromise by using a cervical collar only.

Airway management 0319 This comprises clearing, maintaining and protecting the airway at risk and may need to be supplemented by ventilatory support. If the casualty's neck is bent and there are problems maintaining the airway, gently move the head into the 55

Chemical Casualties: see Chapter 2 (A) (B) (C) Fig 0305The head must be immobilised during application in (A) the cervical collar is sized from the tip of the chin to the top of trapezius. the vertical (B) and horizontal positions (C).

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Try simple airway manoeuvres first. If the casualty gags or coughs, stop and use another method.

Ventilation is generally beneficial after severe head injury. Attempting to intubate the semiconscious casualty may Fig 0306 Chin lift: in the unconscious casualty, this may be aided by increase intracranial placing the thumb in the mouth. Avoid extending the neck . pressure and worsen the situation. neutral position. Stop if there is resistance, or the casualty complains of pain. Immobilisation may have to be in a suboptimal position.

0320 Clearing the airway • In a casualty with an altered level of consciousness, the tongue falls back and obstructs the hypopharynx. This can be corrected by a chin-lift (Figure 0306) or jaw thrust (Figure 0307) manoeuvre. Jaw thrust is preferred because it is will successfully open an obstructed airway in 95% of casualties (chin lift 70-80%) and is less likely to destabilise a cervical spine fracture. • Blood and vomit should be aspirated under direct vision i.e., use a torch or laryngoscope. Alternatively, perform a finger sweep using a gauze swab wrapped around the fingers. Solid material may be removed with the aid of Magill forceps. Do not inadvertently push foreign bodies further down the airway. • Where airway obstruction is due to a fractured maxilla, attempt to reduce it as in Figure 1805. A mandibular fracture may destabilise the tongue; treatment is to pull the mandible and tongue forward until the airway can be maintained by other means. 57 Chapter_3.qxd 28/09/2004 15:54 Page 58 3: Battlefield Advanced Trauma Life Support

OPA and NPA devices maintain the airway but do not protect from aspiration. This can only be prevented by a secure (definitive) airway i.e., a cuffed tube placed in the trachea by the surgical route or by endotracheal intubation.

Fig 0307 Jaw thrust: fingers are positioned behind the angle of the mandible. Place palms on cheekbones for counter traction.

0321 Maintaining the airway Clearing the airway may result in an improvement in level of consciousness and the casualty being able to breath unaided and protect their own airway. It may then be safe to turn them into the three-quarters prone position (Figure 0308). NB: consider cervical spine injury. If they cannot maintain their own airway, continue with jaw thrust or chin lift; alternatively, use an oropharyngeal (OPA) or nasopharyngeal airway (NPA). An OPA (e.g., Guedel, Figure 0309) is simple and quick to insert. A NPA (Figure 0310) can be used when there is oral injury, a fractured mandible or masseter spasm. It is better tolerated than an OPA and is less likely to be dislodged during transfer.

58 Fig 0308 Three-quarters prone position.

Insertion of OPA: see 3002 Insertion of NPA: see 3003 Chapter_3.qxd 28/09/2004 15:54 Page 59 3: Battlefield Advanced Trauma Life Support

Oxygen mask Reservoir bag

O2

Fig 0309 Insertion of an OPA. Place a mask and reservoir bag over mouth and nose.

A suspected fractured base of skull is a relative contraindication for its use: if it is needed to maintain an airway, use it!

0322 Protecting the airway at risk This requires advanced airway techniques: a surgical airway (cricothyroidotomy 3005 rarely, tracheostomy 3007), or endotracheal intubation (3009). Insertion of an appropriate tube into the trachea maintains a clear passage and the cuff provides a protective seal 59

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Fig 0310 Insertion of NPA. Lubricate well and stay close to the floor of the nose. against aspiration. Indications include: In casualties being evacuated • Real or anticipated difficulty clearing by air, inflate the and maintaining an airway: cuff with saline; air expands with • Maxillofacial and neck injuries. increasing altitude. • Face and airway burns. • Obstruction due to swelling or aspiration. It is not lack of intubation that kills, • Continued loss of consciousness. it is lack of oxygen! • To allow accurate control of oxygenation and ventilation (e.g., general anaesthesia, treatment of head injury). • Management of some chest injuries. • Safe transfer of “at risk” casualties. 60

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Unless an anaesthetist is available, or you are Do not use the mouth-to-mouth experienced and have access to anaesthetic drugs or mouth-to-mask for those too awake to intubate without their use technique if there (i.e., GCS >4), a surgical airway is recommended. is a chemical agent Endotracheal intubation without drugs, has very little, vapour hazard either in the if any, part to play in airway management in trauma. environment A laryngoscope and endotracheal tube in the wrong or on the casualty. hands, can deprive casualties of oxygen! A cricothyroidotomy can be performed under LA and is easier than a tracheostomy in the field. Commercial sets are available for rapid access using a Seldinger guide wire technique. There are limited indications for needle cricothyroidotomy (3004). Both the laryngeal mask airway (LMA) and Combitubes have been used in civilian practice to manage the trauma casualty's airway. Their role in military trauma has still to be evaluated.

Breathing and ventilation 0323 Thoracic trauma can be penetrating and/or

blunt (includes blast injury). Occasionally, injury is Tracheal deviation occult e.g., a missile tracking across the diaphragm and cyanosis from the abdomen. Pulmonary function is affected by are late signs of the degree of lung tissue damage and the presence a tension pneumothorax. of blood and air in the pleural cavity. This may or may You must perform not be accompanied by rib fractures and an open a needle wound; both can compound the problem. thoracocentesis. Having assessed the casualty, you must decide whether they: • Require resuscitation thoracotomy as part of the primary survery (rarely indicated) (1529). • Require urgent thoracotomy (1530). • Have thoracic pathology requiring non-surgical treatment e.g., insertion of a chest drain (3013). • Do not have significant thoracic injury.

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Performing a Tension pneumothorax needle thoracocentesis in a 0324 Features suggestive of a tension casualty who does pneumothorax are illustrated in Figure 0311. If you not have a tension pneumothorax may suspect the diagnosis, perform an immediate needle produce a thoracocentesis (3012) on the most likely side. NB: pneumothorax can be bilateral. or lung damage in 10 to 20%. Open pneumothorax (“sucking chest wound” 1508) On the battlefield, it is safer to 0325 For wounds <12 cms in diameter (size of follow needle closed fist), apply an Ashermann seal (3011), or thoracocentesis by occlusive dressing; follow this by insertion of a chest insertion of a drain remote from the defect (3013). Cover any exit chest drain. wounds with an occlusive dressing. Wounds >12 cms in diameter are managed by If respiratory distress supervenes applying the external cover of a field dressing following the (clean side against the wound) taped to the skin on application of all sides. Insert a chest drain remote from the wound. occlusive dressings If the defect overlies the normal site of insertion, the and before the insertion of a chest drain may be laid in the wound before the application drain, assume the of occlusive dressings. In a dire emergency, the chest development of drain can be inserted through the defect, irrespective a tension of its location. pneumothorax and perform needle Small chest wall defects (<1cm) are more likely thoracocentesis. to result in a tension pneumothorax than a sucking wound. If there is respiratory distress, perform an immediate needle thoracocentesis (3012), apply an occlusive dressing followed by insertion of a chest drain (3013).

Massive haemothorax On an erect chest X-ray, at least 500 ml 0326 This is usually due to a penetrating wound of blood can be disrupting the systemic or pulmonary vessels. hidden behind the Each hemithorax can hold up to 2·5 litres of blood. shadow of the diaphragm. Clinical signs are of hypovolaemic shock and A massive respiratory distress, with absent breath sounds haemothorax is and dullness to percussion on the affected side defined as >1500ml. (Figure 0302). 62 Chapter_3.qxd 28/09/2004 15:54 Page 63 3: Battlefield Advanced Trauma Life Support

Distended Anxious The injured lung neck veins Agitated is sensitive to over hydration as Cyanosis Dyspnoea well as hypovolaemic Tachypnoea shock - give i.v. Trachea deviated fluids carefully. towards normal side

Chest wound

Hyper-resonant Reduced/absent breath sounds

Mediastinum pushed towards Hypotensive opposite side Cold and clammy Subcutaneous emphysema

Fig 0311 Features of a tension pneumothorax

Treatment is i.v. fluid resuscitation followed by insertion of a chest drain if there is respiratory distress (3013). Most cases will stop bleeding spontaneously. In the absence of respiratory distress (RR < 30), consider delaying chest drainage until there are facilities for immediate thoracotomy: inserting the drain can lead to circulatory collapse as the tamponading effect of blood in the chest cavity, is released.

Flail chest 0327 This occurs when a complete segment of chest wall loses bony continuity with the rest of the thoracic cage (Figure 1502). Associated features are haemothorax and underlying lung contusion, the latter being the main problem. Field management involves inserting a chest drain and appropriate pain relief (Figure 0701). Use of intercostal nerve blocks (0736) can reduce pain and aid respiration. Subsequently, a period of positive pressure ventilation may be required.

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Cardiac tamponade 0328 Leakage from the heart or great vessels into the pericardial sac is commonly due to a penetrating injury. Unless small, it is usually immediately fatal - the most likely outcome on the battlefield. Consider the diagnosis in casualties with a penetrating chest injury who do not rapidly respond to resuscitation. Classical signs are hypotension, muffled heart sounds and distended neck veins (Beck's triad). An open subcostal pericardiocentesis is preferred (1542). Needle pericardiocentesis even with monitoring, is rarely effective (3015). A subsequent thoracotomy is required for direct repair of the cardiac injury.

Ventilatory support Unconscious casualties without 0329 The aim is to improve gaseous exchange in a definitive airway the lungs and to breathe for the casualty if spontaneous must not be ventilation has stopped, or is inadequate. Indications transferred lying for assisted ventilation include: on their backs. • Head injury.

A face mask • Chest injury, usually lung contusion. without a reservoir bag can deliver • Respiratory depression 35-60% oxygen. (e.g., nerve agents and opiates). With a reservoir this increases to 85%. Assisted ventilation can be achieved by the following A correctly fitting techniques: bag-valve-mask with a reservoir, • Mouth to mouth (NB: pinch nostrils) or mouth will deliver up to to nose. Use a face shield where available. 100% oxygen. • Mouth to mask (Figure 0312) • Bag-valve-mask (Figure 0313) • Bag-valve surgical airway (3005) or intubation (3009). • Automatic ventilation. The aim is to achieve obvious chest movement at a 64 rate of approximately 12-15 breaths per minute (one

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Fig 0312 Mouth to face mask ventilation. NB: Combined with Jaw thrust.

breath, release for three to four seconds). An oxygen source and reservoir should be attached. If there is no oxygen inlet, place the oxygen tubing under the side of the mask.

Circulation with haemorrhage control Crystalloids are 0330 The treatment of shock is to restore cellular cheap and safe and organ perfusion with oxygenated blood. Think of but, only remain in the circulation for 30 haemorrhage as either compressible: you can deal minutes. with this, or, non-compressible: a surgeon deals with Three volumes are this. External haemorrhage must be arrested. This is required to replace more important than establishing i.v. lines. Remember, one volume of blood blood on the floor is forever lost to the casualty! lost. Colloids remain in circulation for longer and replace lost volume on a one-to-one basis. They become viscous below 10°C.

Fig 0313 Bag-valve-mask (BVM) ventilation. NB: Combined with 65 Jaw thrust. Chapter_3.qxd 28/09/2004 15:54 Page 66 3: Battlefield Advanced Trauma Life Support

Fig 0314 Use of a tourniquet.

Options for haemorrhage control include local pressure (digital, pressure dressing), elevation, compression over the brachial or femoral arteries Attempts to control bleeding by and application of a tourniquet. the blind insertion of • One or more sterile field dressings are packed a clamp or artery forceps into the into the wound and held in place with a firmly depths of a wound applied crepe bandage (0502). It they become are unlikely to be saturated with blood cover with fresh dressings. successful and Removal of the original dressing risks dislodging may cause further damage. any clot that has already formed. • It may be possible to reduce bleeding from a puncture wound in the root of the neck or groin by inserting a urinary catheter, inflating it with 50-60ml of water and pressing over the balloon. A technique for safely applying pressure to a neck wound is to place a rolled-up dressing over the defect and an i.v. fluid bag on the opposite side and to firmly bandage around both. • Tourniquets should only be used to control life-threatening haemorrhage when all other 66 measures have failed. The ideal tourniquet is Chapter_3.qxd 28/09/2004 15:54 Page 67 3: Battlefield Advanced Trauma Life Support

broad and can be applied single-handedly by the casualty. It should be positioned as distally Unless released as possible to preserve limb length should for 2-5 minutes every hour, a amputation become necessary. Place a pad tourniquet is likely over the artery to be compressed. Tighten until to cause irreversible bleeding stops (Figure 0314). Record the time soft tissue damage and draw the letter 'T' on the casualty's forehead; after 6-8 hours necessitating release it hourly. Often, on first release, you will amputation. find that bleeding has ceased or local pressure You are sacrificing will suffice! the limb to save the casualty's life. • Clotting adjuncts are currently under trial. These take the form of impregnated sponges, dry fibrin sealant dressings, water absorbent granules which concentrate clotting factors or sytemically administered clotting factors (e.g., recombinant Factor VIIa).

0331 Splint and immobilise fractures and extensive soft tissue wounds by any means available (Figures 0315, 0316). Elevate the part if possible (Figure 0317). Malleable (e.g., SAM splint Fig 0318), inflatable or vacuum splints, provide good emergency support. Where available, use a traction splint for a fractured femur (e.g., Sagar splint Fig 0319) or apply

Fig 0315 Immobilisation of upper limb injuries in the field. 67

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Fig 0316 Immobilisation of lower limb injury in the field.

a Thomas splint with a Crookham halter. (Figure 0320). In addition to holding the fracture, traction has the effect of converting the initial spherical wound haematoma into a smaller volume ellipse, thereby reducing blood and tissue fluid loss (Figure 0321). In anteroposterior compression pelvic fractures (open book - 1305), some control of bleeding may be achieved by pelvic splinting (Figure 0322).

0332 Non-compressible haemorrhage requires “hypotensive” resuscitation and urgent surgical control. Occasionally, an immediate thoracotomy or laparotomy is necessary, as part of the primary survey in casualties with major bleeding.

0333 Restore circulation to an acceptable level. Establish two large calibre intravenous lines (i.e., size 12 or 14) in both antecubital fossae. Where this is not possible, perform a cut down (3017) or a femoral vein cannulation (3019). Intra-osseous fluid infusion is an option when intravenous access is difficult or impractical. 68

Damage Control Surgery: see Chapter 4 3: Battlefield Advanced Trauma Life Support 69 Collar and cuff for Collar and cuff supracondylar fracture St John sling St Standard sling Standard Sling for fractured humerus Fig 0317 Supporting the injured arm. Chapter_3.qxd 28/09/2004 15:54 Page 69 Page 15:54 28/09/2004 Chapter_3.qxd Chapter_3.qxd 28/09/2004 15:54 Page 70 3: Battlefield Advanced Trauma Life Support

For dislocated shoulders fold to form a triangle “Airplane splint”

The splint can be doubled for increased strength

A T-bend increases strength

The ankle is splinted with Two splints can be a single splint - folded under the used one on each side foot and applied to each side for knee or leg injuries

Fig 0318 Uses of the (Splint Aluminuim Maleable) SAM splint.

Civilian data Infuse warmed crystalloids or colloids. Where suggest that, available, use blood in Class III or IV haemorrhage where urgent as an adjunct to surgery. In the shocked casualty, transfer is possible, “scoop and scoot” give fluid at a rate that will quickly restore the radial is better than pulse. Thereafter, infuse according to response. “stay and play” The aim is to obtain a blood pressure sufficient to maintain tissue perfusion to vital organs (~ 90mmHg), that is, a just palpable radial pulse. Over enthusiastic resuscitation causes rebleeding by inducing transitory rebound hypertension, hypothermia (unless the fluid o is at 37 C) and dilutional coagulopathy. In fit soldiers, a systolic pressure of 75-80 mmHg, is acceptable. If it is possible to urgently transfer a casualty with non-compressible haemorrhage to a surgeon, do not delay by attempting to gain i.v. access and starting 70 Chapter_3.qxd 28/09/2004 15:54 Page 71 3: Battlefield Advanced Trauma Life Support

Fig 0319 Application of the Sagar traction splint for femoral fracture.

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Fig 0320 Immobilisation of a fractured femur using a Thomas split and Crookham halter.

resuscitation. Follow the algorithm in Table 0302. Hypertonic saline dextran (HSD) is used in some units for emergency fluid restoration (1ml replaces 10ml lost). Give casualties suffering from non-compressible haemorrhagic 100ml HSD i.v. over 5 minutes. Further aliquots should be administered as required to maintain a radial pulse. Where transfer time is prolonged, a total of 5 x 100ml aliquots may be administered before conventional fluid therapy is started.

Fluid Resuscitation: the end point of resuscitation: a palpable radial pulse Compressible haemorrhage Not shocked Control/no fluids Compressible haemorrhage Shocked Control/i.v. fluids Non-compressible Urgent No fluids haemorrhage transfer Non-compressible Transfer i.v. fluids haemorrhage delayed

Table 0302 Summary of battlefield fluid resuscitation. 72 Chapter_3.qxd 28/09/2004 15:54 Page 73 3: Battlefield Advanced Trauma Life Support

Fig 0321 Traction reduces the volume of the fracture haematoma.

Assess effects of resuscitation 0334 Monitor: • Alertness (AVPU, GCS 1611). • Respiration (rate, expansion and symmetry). • Pulse rate and rhythm. . • Capillary refill time. • Blood pressure. • Urinary output (ideal: adults 50ml/hr - children 1-2ml/kg/hr). • Pulse oximetry/ECG (if available). • Arterial blood gases (if available).

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Remember every orifice merits a finger, a light or a tube.

Figure 0322 Immobilisation of a fractured pelvis in the field. Place padding between pressure points.

Secondary Survey and Packaging

0335 Carry out a secondary survey when and only when the casualty is stable. Remember: all of us have backs, sides tops and bottoms, as well as lots of holes, both natural and as a result of injury, all should be examined! Perform a log roll where spinal injury is a possibility (Figure 0323).

74 Fig 0323 Performing a four-man log roll.

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Examine systematically: • Scalp and vault of skull (1618). • Face and skull base (1805). • Neck and cervical spine. • Chest (0310). • Abdomen (1206). • Pelvis (1310). • Limbs (0903). • Spine and neurological examination (2006).

0336 Following polytrauma, take X-rays of the lateral cervical spine, pelvis and chest. In penetrating chest injuries, perform an additional abdominal X-ray. Look for: • Foreign bodies. • Position of fractures (NB: fractures of the transverse processes and first and second ribs indicate severe force). • Position of any tubes. • Soft tissue injury, evidence of lung contusion, pneumothorax and/or haemothorax.

0337 Methods used to aid the diagnosis of intraperitoneal bleeding following blunt trauma include: • Focused Abdominal Sonography for Trauma (FAST-1213). • Diagnostic Peritoneal Lavage (DPL 1212). • CT scanning (1214). Penetrating abdominal injury invariably requires a laparotomy.

75 Chapter_3.qxd 28/09/2004 15:54 Page 76 3: Battlefield Advanced Trauma Life Support Packaging prior to transfer Whenever possible and if the situation 0338 Consider the following: does not demand a “scoop and scoot” • Is the airway secure? approach, the casualty must be • Is in-transit (escort) care adequate? adequately packaged before transfer. • Explain and reassure. • Analgesia (Figure 0701). • Antibiotics (0813-0822) and tetanus toxoid (0828). • Insertion of a urinary/suprapubic catheter (Figure 1409), nasogastric tube or chest drain (3013). • Stabilisation of fractures and soft tissue injuries. • Where indicated, fix to a spinal board or vacuum mattress (Figure 0324) • Record events. Whenever possible and if the situation does not demand a 'scoop and scoot' approach, the casualty must be adequately packaged before transfer. Once in an evacuation vehicle, especially a helicopter, dealing with a deteriorating casualty is virtually impossible. Even simple monitoring procedures can be difficult.

Definitive Care

0339 Definitive care generally takes place in rear areas and is discussed in the relevant Chapters. It is equally important to remember that if you do not get the primary survey and resuscitation phases correct, definitive care may be in the hands of the War Graves Commission!

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Damage Control Surgery

Introduction

0401 The traditional role of surgery in the management of torso trauma is to control bleeding and, within the abdomen, deal with enteric, biliary and pancreatic spillage. This is usually attempted by definitive repair or removal, of damaged structures. It has been demonstrated that this approach can be associated with an unacceptably high mortality in the severely injured. The recognition that outcomes are determined by the physiological limits of the seriously injured casualty, rather than by the efforts of the surgeon to restore disrupted anatomy, has led to the acceptance of “damage control” being the optimal surgical approach for selected victims of major trauma. In other words, the approach that is most likely to save life. Descriptive terms applied to this process include: abbreviated laparotomy, bail-out surgery and temporary abdominal closure. These terms imply damage control is only applicable to abdominal trauma; this is not the case. For this reason, the term “damage control surgery” (DCS) is preferred, especially in the context of military trauma. Put simply, DCS techniques are applied when the magnitude of tissue and organ damage are such that, prolonged surgery is likely to exceed the casualty's physiological limits. The concept is that only the minimum is done to deal with life-threatening problems. Examples include: methods for rapid control of bleeding, control of enteric spillage without restoration of gut continuity, tractotomy for 79

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penetrating lung injury, rapid amputation of a mangled limb in the presence of other equally NB: laboratory serious injuries and temporary restoration of blood measurements for flow to a limb using vascular shunts. Further surgery standard laboratory is then delayed until various physiological parameters values are obtained on specimens have been restored to as near normality as possible. warmed to 37°C, hence in-vitro clotting times may Why Perform DCS? be normal in the face of in-vivo 0402 The commonest cause of death on the coagulopathy battlefield is shock due to blood loss. Hypovolaemic due to hypothermia. shock leads to the onset of three inter-related variables: metabolic acidosis, profound hypothermia and overt coagulopathy (Figure 0401). Each of these factors reinforces the others and contributes to the death of the casualty, usually by exsanguination. Metabolic acidosis occurs as a result of reduced tissue perfusion and oxygenation triggering the onset of anaerobic metabolism. Hypothermia is induced or compounded by: reduced heat production due to shock, a low ambient temperature, exposed body cavities (operative or traumatic), anaesthetic agents and infusion of cold fluids. A core temperature below o 35 C, significantly affects coagulation despite normal levels of clotting factors. Mortality in casualties with o a core temperature below 32 C, approaches 100%. By comparison, aggressive re-warming is associated with a reduction in mortality, blood loss, fluid requirement, organ failure and in subsequent length of time to recovery.

When to Perform DCS?

0403 The majority of battlefield casualties require The onset of diffuse bleeding in a cold traditional surgical management (0401). DCS should casualty implies the be limited to the minority who are critically unstable. physiological limit These will usually have multi-visceral injuries and for that casualty exsanguinating haemorrhage; DCS is an integral part has already 80 been passed. of resuscitation for this group. In one large civilian

Amputation: see Chapter 11 Hypothermia: see Chapter 26 Chapter_4.qxd 28/09/2004 15:54 Page 81 4: Damage Control Surgery

Major Trauma

Hemorrhage

Progressive latrogenic Factors Coagulopathy Cellular Shock Hypothermia

Tissue Injury Metabolic Acidosis

Contact Activation Massive Transfusion Clotting Factor Deficiency Pre-existing Disease

Fig 0401 Consequences of major trauma.

series, DCS was only necessary in 5% of casualties requiring laparotomy for trauma. This figure is likely to be higher in military practice, where surgical facilities can be exposed to simultaneous multiple casualties - when operative procedures should be as short as possible - and where the surgeon may lack the skills or equipment for complex reconstruction. In the latter case, simple, short procedures will often produce the best results. The decision to adopt a DCS approach to casualty management should be taken in the early stages of surgery or, better still, before surgery is started. The longer the decision is delayed, the more futile the process becomes because the outcome is likely to be unfavourable. Some of the factors that indicate the need for a damage control approach, are in Tables 0401 and 0402.

0404 Disadvantages of DCS include: an increased consumption of resources (e.g., transfusion, stapling devices, ITU facilities etc., all of which may be 81

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severely limited) and the potential build up of post-operative DCS casualties requiring time consuming and complex second-look surgery in the next 24 to 48 hours. In such circumstances, techniques such as intraoperative autotransfusion of blood and a “minimal transfusion” approach, are helpful in reducing the need for blood products. To ensure that resources are not "wasted" on the unsalvageable casualty (DCS is not synonymous with futile care!), triage protocols driving casualty selection for DCS, must be rigorously enforced.

1 Haemodynamic instability 2 Multiple torso penetrating injuries 3 Survivors of class IV haemorrhage 4 Pre-operative core temperature <35°C 5 Arterial pH < 7.3 6 Serum lactate > 5mmol/l 7 Established coagulopathy: PT or PTT > 50% normal 8 Multiregional injuries, e.g., quick laparotomy before neurosurgery

Table 0401 Pre-operative casualty selection for DCS.

1 Resuscitation and operative time exceeding 90 minutes 2 Core temperature 34°C or less (further surgery is probably futile) 3 Worsening non-mechanical diffuse bleeding 4 Massive transfusion, > 10 units packed cells (unlikely in a war setting)

Table 0402 Per-operative indications for DCS.

82 Chapter_4.qxd 28/09/2004 15:54 Page 83 4: Damage Control Surgery DCS Techniques

Initial operation

Incision: 0405 Always make generous incisions. For abdominal injury, perform a full midline incision (Figure 0402), with the casualty draped to allow extension into a thoracotomy, median sternotomy or to gain vascular access at the groin.

Laparotomy 0406 Evacuate the haemoperitoneum and pack the four abdominal quadrants and pelvis. Carefully removing each one in turn should allow identification of the sources of bleeding (Figure 0403). Perform a systematic laparotomy looking for organ damage and other sources of blood loss (Figure 0404).

Median Anterio- sternotomy lateral thoracotomy

Thoraco- abdominal Transverse through extension 6th interspace

Incision for exposure of vessels at the groin

Fig 0402 Standard abdominal midline incision for trauma. Drape the casualty so as to allow extension into the chest and vascular access. 83

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Left upper quadrant

Subhepatic

Left lower Right lower quadrant quadrant

Retrovesical pouch

Fig 0403 The classical sites for blood to collect in the abdomen. Initially control by packing. A peacetime manoeuvre for controlling torrential abdominal haemorrhage is to clamp the thoracic aorta through a left anterolateral thoracotomy (Figure 0405). Visualisation may be easier than controlling the abdominal aorta above the coeliac axis (Figure 0406). Both techniques are unlikely to be applicable in the field (1276).

4 3

5

2

1

Fig 0404 Perform a systematic laparotomy NB: examine both leaves of the small bowel mesentery. Consider opening the lesser sac, 84 mobilising the colon/rectum and “Kocherising” the duodenum.

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Lung

Clamp across aorta

Pericardinal sac

Phrenic nerve Oesophagus

Fig 0405 Clamping the thoracic aorta to temporarily control torrential abdominal haemorrhage.

Control of haemorrhage 0407 This is achieved by direct means using sutures, ligatures, clips and diathermy, or indirectly, by packing or various tamponade techniques. Packs should be so placed as to re-approximate disrupted tissue planes. Unless packing is effective at the time of laparotomy, the hope that time, tamponade and haemostatic mechanisms will control bleeding, especially if arterial in origin, is futile. In this case, repack or use other means. Conversely, overpacking within the abdomen risks compressing the inferior vena cava thereby increasing intra-abdominal pressure and reducing venous return (1258). Packing may also be used to control pelvic and retroperitoneal bleeding. Clotting adjuncts, such as recombinant factor VIIa (rVIIa), are currently under investigation (0330). Preliminary results suggest timely administration of rVIIa will help control severe haemorrhage.

Liver Injury 0408 Compression is the quickest and most effective method of controlling bleeding from a disrupted liver; it is even applicable following retrohepatic caval injury (Figure 0407). The injured lobe is mobilised and compressed by packs placed above, below and lateral, or in front and behind 85

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Liver

Stomach

Fig 0406 Clamping the abdominal aorta above the coelic axis. (Figure 0408). The key is to pack the liver so as to re-approximate its shape and not to force packs into disrupted liver substance. A non-crushing clamp placed across the structures in the free edge of the lesser omentum (Pringle’s manoeuvre), will reduce blood flow to the liver via the portal vein (70% of hepatic blood flow) and hepatic artery (Figure 0407). Continued bleeding following liver packing and release of the clamp, indicates bleeding from the retro-hepatic vena cava. Balloon tamponade can be used to control deep or through-and-through hepatic wounds. A Penrose drain tied at one open end then passed over a rubber tube and tied around the inner tube at the other end, then inflated via the tube, gives good tamponade along a lengthy wound track (the same principle as a Sengstaken tube compressing

Pringle manoeuvre

86 Fig 0407 Manually compression and Pringle’s manoeuvre to control hepatic bleeding. Chapter_4.qxd 28/09/2004 15:54 Page 87 4: Damage Control Surgery

Liver laceration

Packs behind and lateral to liver

Fig 0408 Placing packs to compress the liver.

oesophageal varices). Vena caval tamponade using a Foley catheter inserted via a small venotomy, can be used as a last resort (Figure 0409). Splenic injury on the battlefield necessitates splenectomy (1251).

Abdominal visceral injury. 0409 Spillage following damage to the gastrointestinal tract may be controlled by tying with tapes, simple runnning sutures or the use of stapling devices, including skin staples (Figure 1204). The closed-off loops of bowel are returned into the abdominal cavity. Large bowel perforations may be exteriorised in the manner of a loop colostomy (Figure 1213); small perforations can be closed quickly using skin staples. Biliary (Figure 0410), pancreatic (Figure 0411) and urinary leaks (1408, 1417, 1421), should be controlled by external tube drainage. All reconstruction is deferred until relaparotomy Chest wounds 0410 Thoracic injuries do not lend themselves to packing as a means of controlling blood loss. Cross clamping the hilum (Figure 1549) or rotating the lung through 180 degrees after dividing the inferior pulmonary ligament, will control major lung haemorrhage and/or air leak. Other useful DCS techniques include: non-anatomical lung resection 87

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Catheter balloon inflated above liver

Pringle manoeuvre

Rubber sloop around IVC below liver

Fig 0409 Massive liver bleeding: isolating the vascular supply using Pringle's manoeuvre and controlling the IVC with a balloon catheter and sloop. using staples (Figure 1550) and tractotomy (Figure 1514). The latter is achieved by passing two long arterial clamps down the length of a penetrating wound, the tissue between the clamps is then divided This allows the wound to be inspected, vascular control obtained and an airtight seal effected by oversewing the tissue in the clamps (1550). The

Fig 0410 Draining the biliary tree: cholecystostomy tube and 'T' tube 88 in the bile duct.

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same procedure can be done more quickly employing linear staplers in place of clamps. Shunts may Vascular injuries become dislodged e.g., during transfer, 0411 Simple repair is the preferred treatment leading to sudden following vascular trauma. It can usually be completed unrecognised quickly and will control haemorrhage and restore haemorrhage. They should only be circulation. Other options include: ligation, placement used where trained of a temporary vascular shunt or insertion of a personnel are synthetic graft: available to monitor and treat this • The risk of critical limb ischaemia (CLI) complication. necessitating limb amputation following ligation of a supplying vessel, is shown in Figure 0412. CLI is more likely if there is extensive soft tissue trauma causing damage to collateral vessels and in elderly casualties with pre-existing vascular disease. When necessary, all leg veins and the inferior vena cava can be ligated (1277). This is likely to result in varying degrees of limb oedema. The individual jugular veins can be tied off without major sequelae. In extremis, the portal vein can be ligated; this is likely to result in massive ascites (1280). • A Shunt can be used to temporarily restore distal blood flow (Figure 0413), allowing time for return of normal physiology, transfer to a vascular surgeon, or whilst first attending to higher priority injuries. Examples include: bridging a defect in the common femoral artery or carotid artery and re-establishing venous return following major vein injury. Shunts may be purpose made (e.g., heparin-bonded silastic, Javid shunt) and held in place by ring clamps or snugging devices, or extempore shunts. A length of sterile plastic tubing (e.g., cut from a giving set), inserted into both ends of the damaged artery and held in place with double ties, will suffice. Complications include: shunt displacement, thrombosis and intimal damage. Alternatively, 89

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Retracted Stomach

Exposed common bile duct

Pancreatic duct

Nasogastic tube

Drain Balloon catheter

Fig 0411 Placing balloon catheters and drains to control a major tear of the head of the pancreas and duodenum.

consider inserting a synthetic graft (GoreTex™ is preferred) - this is almost as quick in the right hands, as shunting. • Where available, angiographic embolisation may complement other methods of haemostasis.

Temporary abdominal closure 0412 Formal abdominal closure is unnecessary in the interval before relaparotomy. Techniques include: 90 closure of the skin only using clips or a running Chapter_4.qxd 28/09/2004 15:55 Page 91 4: Damage Control Surgery

Axillary/ high brachial 25 - 50%

Common iliac Brachial 75% 25% External iliac 30% Radial Common 5% femoral Ulnar 50% 2% Profunda femoris 1% Superficial femoral 10 - 30%

Popliteal 60%

Anterior tibial 5 -10%

Posterior tibial 5 -10%

Fig 0412 The likelihood of emergency arterial ligation leading to limb amputation in a young fit casualty. suture or, suturing a piece of plastic (e.g., infusion bag) to the wound edges (“Bogota Bag”). A sutureless technique that reduces the likelihood of abdominal compartment syndrome and prevents soiling of the ward bed, is the “Opsite sandwich”. An abdominal pack is opened out and covered by the adherent surface of a sheet of Opsite™ (1290). This sandwich is tucked under the edges of the wound (rectus muscle) and two suction drains placed over it. The entire wound is then occluded with a large Opsite sheet and the drains attached to continuous, low-pressure suction (Figure 0414). 91

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Fig 0413 Insertion of a temporary arterial shunt.

Restoring Normal Physiology

Laboratory tests 0413 Interventions include: of coagulation and haematocrit • Mechanical ventilation to improve oxygenation lag behind real-time and removal of CO2. blood-loss and empirical transfusion • Enhancing oxygen delivery. Therapeutic options is recommended. include: improving cardiac output with volume Placement of a infusion and inotropic drugs and increasing pulmonary artery oxygen-carrying capacity by blood transfusion. catheter will allow measurement of • Rewarming can be achieved by increasing oxygen transport the ambient temperature to the thermoneutral o parameters. zone (28-30 C), employing external warming devices and warming all intravenous fluids and ventilator circuits. • Restoration of normal coagulation using fresh frozen plasma and platelets

Re-operation

Timing 0414 Timing of further surgery depends on the casualty's condition and the type of trauma e.g., an injury requiring revascularisation calls for earlier, definitive repair than reanastomosing stapled bowel. Ideally the casualty should be normothermic with 92 a normal coagulation profile. Conversely, delaying

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Opsite sheet Suction drain Abdominal wall

Gauze swab wrapped in Opsite

Fig 0414 Temporary abdominal closure: the Opsite™ sandwich. surgery beyond 72 hours may lead to sepsis, ARDS and organ failure. The majority of casualties are returned to the operating theatre between 6 to 48 hours post-DCS. In a military setting, the tactical situation may need to be considered when deciding timings for re-operation. If the surgery has been carried out in a forward mobile unit, the casualty should be transferred rearward as soon as possible, ideally using “helevac”. The most suitable time is likely to be soon after surgery when there is physiological improvement. Delay beyond this may see the onset of deterioration demanding surgical intervention beyond the capability and capacity of a small, mobile unit. The unit's mobility may also be compromised. Re-operation should ideally, be carried out in a well equipped, well resourced field hospital.

Other onsiderations 0415 Relaparotomy provides an opportunity to search for the 10% of intra-abdominal injuries missed at initial operation. They are a potent cause of morbidity and mortality. Classic markers that may alert to this possibility include: a discontinuous missile trajectory, or an odd number of gastrointestinal perforations.

0416 Packs are sequentially removed and repairs inspected, vascular reconstruction may then 93

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be undertaken and urological and gastrointestinal continuity restored. If possible, 'critical' packs should be left undisturbed until the last moment as unpacking may lead to recurrent bleeding and the need for repacking.

0416 Trauma victims have increased nutritional needs and early enteral feeding has been shown to reduce postoperative septic morbidity after trauma. It may be possible to manipulate a fine-bore feeding tube beyond the pylorus, if not, consider a feeding jejunostomy. Intestinal anastomoses are not a contraindication to enteral feeding.

0417 It may not be possible to close the abdominal wall due to distension. Alternatively it may be considered undesirable to do so because of concerns over the development of the abdominal compartment syndrome, or possible need for a further laparotomy. Definitive closure may have to wait until visceral oedema has completely subsided (0412).

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Principles of Wound Management

Comparison of Civilian and Military Wounds

0501 There are important differences; military Delays in transfer wounds are usually: averaged 10 hours between wounding • Caused by penetrating trauma. Involvement of and starting appropriate surgery more than one body compartment or area, is during the 1990-91 common e.g., thigh and pelvic wounds can be Gulf war. complicated by spillage of abdominal contents. By comparison, civilian wounds are usually due to blunt trauma and tend to be associated with solid organ damage. • More heavily contaminated than civilian wounds, notably with Clostridia species and Gram-negative bacteria (0808). • Infected because of delays in transferring the casualty to a surgeon. • Treated in less than ideal circumstances with limited resources. The presence of large numbers of casualties may influence management.

General Casualty Management

Overview 0502 1. Apply Battlefield Advanced Trauma Life Support (BATLS) measures, as soon as the tactical situation permits. 2. Apply a sterile field dressing, or dressings, firmly over the wound. If this becomes saturated, put further dressings on top. Do not remove or loosen 95

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Sterile dressings dressings unless there is evidence of distal limb applied at point of wounding and left circulatory compromise, until the casualty has undisturbed until reached a surgeon. surgery, reduce the risk of established 3. Give systemic antibiotics (0816) and tetanus pre-operative sepsis toxoid (0828) as soon after wounding as possible. from 20% to 5%. Antibiotics should be self-administered or, given by buddy aid within one hour of wounding; they delay the speed of onset of wound infection (0804). 4. Where the missile has penetrated a body cavity, Provided there is no explore via a standard incision (e.g., abdominal urgency to control midline, anterior thoracotomy) and not through haemorrhage, deal with any wounds on the wound. the back first. 5. Initial wound excision followed by delayed primary closure, is the norm for military wounds. .Antibiotics must The wound is lightly packed and the skin left not be regarded open to avoid tension and aid drainage. Ideally, as a substitute excision should be within six hours of wounding. for surgery or a reason for For many soft tissue-only wounds, this time inadequate surgery. frame can be stretched, providing appropriate antibiotics have been administered. Injuries of the face, scalp and scrotum are discussed in 0504. 6. Many superficial fragment wounds can be successfully managed by scrubbing them clean, followed by application of a dressing and antibiotics (0816). 7. Major limb wounds require fasciotomy (0908). Splint fractured limbs and extensive soft tissue injuries. Elevate the injured part. 8. Delayed primary closure is usually performed four to five days after wound excision. Heavily contaminated wounds and limbs that may require amputation, are reassessed at 48 hours. 9. Exposed joint surfaces should be covered at the initial operation to reduce the risk of infection 96 cover vascular suture lines.

Haemorrhage control: see - 0407 Chapter_5.qxd 28/09/2004 15:55 Page 97 5: Principles of Wound Management

10. Consider DVT/PE prophylaxis (0980).

Wound excision

0503 Once the casualty has reached a surgical Neither antibiotics facility, the vast majority of military wounds require nor the method exploration and wound excision or cleansing, under of splintage are GA or LA. The principle is to remove all foreign and a substitute for adequate wound non-viable tissue and to leave the wound open: excision. • Following wounding in a chemical environment, remove hazardous material e.g., clothing, with a no-touch technique. Irrigate the track with dilute Milton or 0.5% hypochlorite solution for 2 minutes. Wash body cavities with saline only. Place foreign bodies and fragments into bleach to prevent "off-gassing" (0230). • All wounds should be thoroughly irrigated at the beginning, during and at the end of the procedure.

• Start by excising the skin (Figure 0501). Remove Traumatic flaps, only that which is obviously beyond survival, once cleaned and repositioned, often or grossly contused. In a penetrating missile recover to provide wound, it is usually only necessary to excise useful skin cover. 1-2mm of the skin edge. Degloving injuries may necessitate more radical excision. • Superficial fragment or low energy-transfer bullet wounds, can usually be managed by scrubbing the wound, applying dressings and administering systemic antibiotics. • If extension of skin wounds is required, incision should be in the long axis of the limb and obliquely or transversely across joints to prevent late contracture (Figure 0502). If for example, the track between entry and exit wounds crosses a joint, do not simply expose the damaged area between these two points; an "S"- shaped incision Avoid opening up intact tissue planes is appropriate. A tourniquet is often helpful for and spreading forearm, hand and foot wounds. In the face, contamination. make incisions parallel to skin creases (asking the casualty to screw their face up will aid 97

Abdominal Injury: see Chapter 12. Thoracic Injury: see Chapter 15 B) Removing damaged deep fascia, C) Excising necrotic muscle, up, plain gauze. D) Loosely dressing wound with fluffed C D B A Fig 0501 the skin edge, Trimming A)

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When using a tourniquet, a broad, pneumatic device is preferred. Aim for a pressure of ~250 mmHg. Do not inflate for longer than 90 minutes. Home made or non-pneumatic devices will cause local tissue damage. Back of leg

Fig 0502 Perform wound extension in the long axis of the wound and obliquely or transversely across joints. In the face, make incisions parallel to skin creases.

identification if surgery is being done under local anaesthesia). • Damaged subcutaneous fat should be removed, but additional areas of degloving must not be created by over generous excision. • Deep fascia should be incised to give adequate access to underlying muscles. Do not incise deep fascia unnecessarily unless it needs to be converted into a fasciotomy. • Adequate excision of all non-viable muscle is essential. Irrigate with warm saline before starting to excise muscle; its colour may change, especially if the wound is very dirty. Excise with care until viable tissue is apparent. Do not gouge out large divots of muscle, this may sacrifice living tissue. But, if in doubt, remove it. 99

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Look for the "four C's" that indicate viability: •Capillary bleeding when cut. •Contracts when pinched.

The inexperienced •Colour of red meat. surgeon may be surprised by the •Consistency firm and not looking like 'stew'. extensive damage caused by a • Do not worry about exposing bone and tendons, standard 5.56mm leaving dead muscle will not provide protection round and will for underlying bone. frequently underestimate the • Many deep limb wounds, crush injuries, open amount of tissue and closed fractures, major vein ligation and requiring excision. re-vascularised limbs, require fasciotomy (0908), splinting (0331) and elevation. • Primary amputation may be necessary as part of the operative management i.e., “radical” wound excision. Below knee amputation is commonly required after anti-personnel mine trauma (0221).

Avoid antiseptic • Nerves, patent blood vessels and tendons in soaked dressings. continuity with muscle, are not excised. Divided If wound excision nerve ends and tendons should be marked with has been adequate, a non-absorbable, monofilament suture for antiseptics are unnecessary and subsequent repair (tendons 3027, nerves 2119). are toxic to bone Exposed bone or tendon does not have to be forming cells. covered at the initial operation, but consideration should be given to early closure of these wounds to prevent desiccation. Bone or tendon left uncovered for long periods will usually require further excision despite appearing viable at initial surgery. All vascular repairs, including grafts, should be covered by muscle: do not apply dressings directly to vascular suture lines (1028); the vessel or graft is likely to thrombose. • All dead and contaminated bone must be removed. The aim is to create a clean and non-infected wound in which later reconstruction 100 can take place. Viability of bony fragments can

Compartment syndrome: see 0906 Chapter_5.qxd 28/09/2004 15:55 Page 101 5: Principles of Wound Management

be difficult to determine. Bone regeneration depends on leaving as much periosteum as possible. Pieces of bone with no, or only minimal, soft tissue attachments, should be removed. Dirty bone ends are cleaned by scraping or use of bone nibblers back to bleeding healthy bone. The same applies to necrotic bone when operating on neglected wounds.

Wounds of the face, scalp and scrotum 0504 Because of their excellent blood supply, wounds in these areas can be closed primarily. Only minimal excision is usually required. Extensive facial wounds usually benefit from a deep layer of absorbable sutures. Try and match up landmarks e.g., edge of lip (Figure 0503). Use closely spaced, 6/0 interrupted nylon sutures for the skin (remove at 4-5 days and apply Steristrips™). Trimming the skin edge may produce a better cosmetic result, especially if the skin is contused. Where there is significant loss of skin and mucosa, tack them together, as in Figure 0503; this can be reconstructed later employing a plastic procedure. Repair of injuries to cartilaginous structures see 1903.

Open joint wounds 0505 Penetrating joint injuries require exploration through the wound or a separate incision, removal of unattached bone or cartilage and foreign bodies, followed by irrigation. Preserve as much synovium and osteochondral fragments as possible. Insert a suction drain. The joint must be covered at the initial operation to reduce the risk of infection. This can be achieved by closure of the synovium using an absorbable suture, or covering the defect with adjacent capsule, muscle or skin. The remaining wound is left open for delayed primary closure. Immobilise the joint and elevate the limb. Repair of the capsule and ligaments is performed at the second operation. 101

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Fig 0503 Facial wounds: only minimal excision of facial wounds is usually required. Closure may necessitate a layer of deep absorbable sutures. Try and match up landmarks. Where there is significant loss of skin and mucosa, approximate using sutures.

Retained foreign bodies 0506 The majority of foreign bodies are removed at the time of initial wound excision: • Fragments - Do not open healthy tissue purely to locate fragments. Retained, radio-opaque foreign bodies, are often found on subsequent 102 radiography. Most can be left, with only a small Chapter_5.qxd 28/09/2004 15:55 Page 103 5: Principles of Wound Management

risk of complications. If wound sepsis occurs, secondary surgery will be required to remove the fragment. • Bullets - If lying subcutaneously, these may be removed. Bullets retained in soft tissues and bone, can be treated conservatively. By comparison, those lodging in joints, bursae or spinal meninges, are preferably retrieved due to the risk of lead arthropathy and toxicity. This can be delayed until after casualty transfer and may be facilitated by arthroscopic techniques.

Irrigation 0507 All wounds should be irrigated with copious amounts of fluid. In the case of open It has been fractures, the bone ends must be washed. Where recommended that 5-10l of sterile fluid supplies are restricted, potable water can be used be used for fracture with a final washout of 1l of sterile saline. Following a irrigation. high energy-transfer wound, tissue planes should be thoroughly irrigated "the solution to pollution is dilution".

Dressings 0508 Wounds should be dressed with large quantities of fluffed up, plain gauze, then covered with cotton wool or Gamgee and the skin left open. Do not pack wounds tightly; this prevents drainage and oxygen diffusion. Bandages and tape used to secure the dressing must not tightly encircle and constrict the limb. Repeated postoperative examination is unnecessary, painful and contributes to the spread of infection; the wound should not be disturbed unless specific indications arise: • Evidence of systemic infection e.g., unexplained pyrexia, tachycardia or toxicity. • Presence of spreading local erythema, oedema or crepitus. 103

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Offensive odour alone is not an indication to take down the dressing.

Superficial fascia Deep fascia

Fig 0504 Undermining of the wound edges to facilitate closure.

• signs of distal vascular insufficiency, NB: remove all restricting bandages and casts (0908). Immobilisation 0509 Splint extensive soft tissue wounds (0331). Sometimes, a bulky dressing is sufficient. Elevate limbs where possible. Fixation of bony injuries is discussed in Chapter 9. NB: walking wounded should not be turned into stretcher cases by inappropriate immobilisation, particularly if mass casualties are present.

Delayed primary closure 0510 Following adequate excision, the wound is generally left undisturbed for four to five days. Heavily contaminated wounds and limbs that may require amputation, are reassessed at 48 hours - earlier, if indicated by the presence of fulminating sepsis. Inspection of large wounds should be performed in 104 theatre under GA. If there is tension, infection or

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necrotic tissue, closure is inappropriate. Perform a further wound excision. Deep exploration of the wound is not routinely performed. If necrotic tissue remains, the tissue planes will fall apart to reveal it. Where appropriate, close the wound in layers. This may require some undermining of the wound edges (Figure 0504). A suction drain is advisable for deep cavities. This may be an appropriate time to perform tendon (3027) or nerve repair (2119). Use staples or monofilament nylon for the skin. Small wounds often close themselves after repeated dressings. Surgical tape, rather than sutures, should be used. A panoply of plastic procedures are available to close wounds too large for complete delayed primary suture (2310). Not infrequently, a combination of skin suture and split skin grafts, are necessary to achieve wound cover.

105

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Triage

Introduction

0601 The management of a single, seriously injured casualty in peacetime, is frequently difficult. On the battlefield, problems are compounded by environment, difficult terrain and tactical constraints. The situation is even more difficult when faced with large numbers of casualties. If a system for prioritisation of care of the injured is not in place, many salvageable casualties may die unnecessarily. Triage (from the French verb trier, to sieve or to sort), has evolved through military conflicts dating from the Napoleonic Wars and American Civil War, to recent civilian disasters. It may be defined as: Sorting casualties and the assignment of treatment and transfer priorities to wounded at each echelon of medical care.

0602 The principles of military triage are: • Do the most for the most. • Use available resources as efficiently as possible. • Transfer rearwards those casualties requiring further treatment who can withstand the journey. • Return personnel to duty as soon as possible.

Triage Priorities

0603 The T (Treatment) System of triage is widely employed. Triage priorities in a compensated situation - when the medical facilities can cope - are: 107 Chapter_6.qxd 28/09/2004 15:55 Page 108 6: Triage

T1 - casualties needing immediate life-saving resuscitation and/or surgery. T2 - stabilised casualties needing early surgery but, delay is acceptable. T3 - casualties requiring treatment but, a longer delay is acceptable. Dead.

Examples of a 0604 In a mass casualty setting, when medical mass casualty facilities are overwhelmed, the situation becomes situation include a single MO with uncompensated and triage priorities must change limited equipment in order to save the maximum number of lives. dealing Priorities become: simultaneously with 6 major casualties, T1 - Immediate Treatment. Casualties needing or a field hospital emergency, life-saving resuscitation and/or surgery. suddenly receiving 100 chemical Procedures should not be time consuming and casualties. concern only those with a high chance of good quality survival. Examples are: remedial airway obstruction, accessible haemorrhage and emergency amputations. Some T2 - Delayed Treatment. Those requiring major ambulatory casualties surgery (after initial treatment such as i.v. fluids, categorised as T3, antibiotics and fracture splinting), or medical may have injuries of treatment, but where conditions permit some sufficient magnitude delay without endangering life. Examples are: to cause clinical deterioration open fractures of long bones, large joint requiring a dislocations and burns covering 10-30% BSA. change in priority. T3 - Minimal Treatment. Casualties with relatively minor injuries, where a longer delay before treatment is acceptable. T3 casualties can effectively take care of themselves or be helped by untrained personnel. Examples are: minor lacerations and uncomplicated fractures. T4 - Expectant Treatment. Multiply-injured casualties needing extensive time-consuming treatment, or with a poor chance of survival. They 108 should receive appropriate supportive treatment

Severe Head Injury: see 1607 Severe Spinal Injury: see Figure 2001 Chapter_6.qxd 28/09/2004 15:55 Page 109 6: Triage

YES WALKING DELAYED PRIORITY 3

NO DEAD

NO NO OPEN BREATHING BREATHING AIRWAY

YES YES

Below 10 RESPIRATORY IMMEDIATE RATE 30 or more PRIORITY 1

10-29

Over 2 sec

Pulse over 120/min CAPILLIARY Under 2 sec URGENT REFILL OR PRIORITY 2 PULSE RATE Pulse under 120/min

Fig 0601 The triage sieve for treatment.

compatible with resources, e.g., analgesia. Examples are: severe head and spinal injuries, extensive burns and large doses of radiation. Once casualties in the other categories have been treated, medical personnel can then turn their attention to survivors in the T4 group. Dead

0605 Categorisation and the level of care provided, depends on resources and casualty numbers. During a mass casualty situation, life- saving treatment may initially be confined to opening airways and stopping compressible haemorrhage.

Triage for treatment 0606 A widely accepted physiological method of triage for treatment is the Triage Sieve. This involves an assessment of the casualty's mobility, followed by airway, breathing and circulation (Figure 0601). 109

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Assessing CRT 0607 Triage is only a 'snapshot' of how the is unreliable in the cold or dark. casualty is at the time of assessment. In order to identify changes, the triage sieve must be repeated In a casualty with a respiratory rate in at each link of the casualty evacuation chain and the the normal range, priority adjusted to reflect deterioration or improvement absence of a radial in the casualty's clinical condition. It is important pulse will put them initially not to try to predict how a casualty may in the Priority 1 category for deteriorate, this will lead to over-triage (a higher than treatment. necessary triage category) and can overwhelm the system with T1 and T2 casualties.

Triage for transfer 0608 Following performance of the triage sieve and initial treatment, casualties should be more stable with, for some, a significant change in their initial triage category. The next consideration is who should be transferred rearwards first and the optimum facility they should go to. Determining priority for transfer can be accomplished with the aid of the Triage Sort. Triage sort uses the respiratory rate, systolic blood pressure and Glasgow Coma Scale, to numerically score the casualty from 0 to 12 and give an indication of priority for transfer and/or the need for further intervention (Figure 0602). This score has a proven direct relationship to outcome from severe injury.

0609 After coding each of the three parameters, add them together to give a score ranging from 0 (dead) to 12 (physiologically normal). Priorities for transfer are assigned as follows: •T1 1-10 •T2 11 •T3 12 •T4 1-3 • Dead 0

110

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Eye opening Spontaneous 4 To voice 3 To pain 2 None 1 Verbal response: + Orientated 5 Confused 4 Inappropriate words 3 Incomprehensible words 2 No response 1 Motor response + Obeys commands 6 Localises 5 Pain withdraws 4 Pain flexion 3 Pain extension 2 No response 1 = Glasgow Coma Scale Total: Total Glasgow13 - 15 4 Coma Scale 9 - 12 3 6 - 8 2 4 - 8 1 3 0 + Respiratory 10 - 29 4 Rate more than 29 3 6 - 9 2 1 - 5 1 0 0 + Systolic BP 90 or more 4 76 - 89 3 50 - 75 2 1 - 49 1 0 0 = 12 = Priority 3 Total: 11 = Priority 2 10 or less Priority 1 Time

0602 Triage sieve.

The overlap in scores for T1 and T4 (expectant) allows for the seriously injured to be placed in either category, depending on number of casualties and available resources. Similarly, where the priority determined by physiology does not match the anatomical severity of injuries, the priority can be upgraded. An example is the soldier with severe haemorrhage from a leg wound. Because of the Circulation problem, he is triaged for treatment using the triage sieve as T1. Following application of a tourniquet and fluid resuscitation the triage sort score is 12 i.e., low priority for transfer. Because he requires urgent surgery, this is changed to T2. 111

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0610 Medical cases are categorised in exactly the same way in relation to their need for resuscitation and timely intervention by a physician.

0611 Psychiatric cases generally fit into the T3 bracket. Treating them as far forward as possible results in the maximum number being rendered fit enough to be returned to duty.

Casualty Transfer Chain

0612 During military operations, casualties are usually transferred rearwards through Echelons of Medical Care. These correspond with the levels of operational deployment: • First Line at unit level. • Second Line at brigade or divisional level. • Third Line between the divisional rear boundary and point of entry. • Fourth Line at the base.

0613 Echelons should not be confused with Roles of Medical Support which is the term used throughout NATO to define levels of medical capability. Role 1 Treatment to restore and stabilise vital functions. (Regimental Aid Post - Unit Aid Post - Medical Section). Role 2 Resuscitation and stabilising treatment. If A&E, surgical and intensive care teams are attached, thereby enhancing capability at this level, this is described as Role 2+. Role 3 Field Hospital. All hospital facilities and support staff. Role 4 Time consuming, specialist and long term treatment, usually back in the home country. 112

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0614 Early surgery is generally carried out at Role 3 (i.e., Field Hospital; Primary Casualty Receiving Ship - PCRS), with subsequent care taking place at a Role 4 hospital There will be occasions when surgery, through a field surgical team being attached, is available forward of field hospitals. This will be the norm in airborne, airmobile and amphibious operations and when surgical teams are attached to Squadrons of Close Support Medical Regiments (previously Field Ambulance). Specialist teams, such as burns, neurosurgery and maxillofacial, are allocated to selected field hospitals. All of these considerations will influence the transfer of casualties.

113

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Analgesia in Forward Areas

Introduction

0701 The priority for most casualties after injury Physiological is rapid and effective pain relief. Pain is a complex response to pain: phenomenon, the perception of which can be affected • Increased by psychological, emotional and physiological sympathetic activity processes. Effective management requires you to causing release of “stress” chemicals deal with all of these aspects simultaneously by: (catecholamines). • Repeated explanation and reassurance. This • Nausea and vomiting. decreases both physiological and emotional • Hyperventilation. factors and is helped by keeping the casualty • Tachycardia. warm, treating them in quiet and familiar • Peripheral surroundings and early transfer. vasoconstriction • Reducing the pain stimulus e.g., by splinting causing reduced tissue O2 delivery. fractures and cooling burns. • Increased O2 • Reducing pain sensation by giving analgesics consumption. using the battlefield protocol (Figure 0701). • Increased intracranial pressure. • Hypoxia, Effects of Inadequate Pain Control hypercarbia and hypovolaemia lower the pain threshold. 0702 Pain exaggerates clinical shock, There is evidence to show that pain relief reduces the potential for serious complications following major injury. Inadequate pain relief is associated with: • Reduced ability to cope psychologically with the effects of injury and surgery. • An uncooperative casualty who is difficult to assess. • Reduced casualty mobility resulting in:

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leading to hypoxia. • Increased risk of DVT (0979). • Delayed recovery from surgery. • Painful casualty transfer.

0703 Pain relief after injury or surgery is Spinal damage frequently inadequate for a variety of reasons: may prevent the casualty feeling pain • Not viewed as a priority by rescuers below the level or medical staff. of the injury. This can result in injuries • Inadequate assessment and reassessment. being missed or worsened. • Analgesia inappropriately withheld e.g., fear of side effects. • Inappropriate method of analgesia, choice of drug and route of administration. • Inadequate dosage. • Inadequate frequency. • Poor operator technique e.g., nerve block.

Analgesia

0704 Careful assessment and reassessment of the casualty's degree of pain and a logical approach to the choice of analgesic technique or drug, are required to achieve the best results. Initial assessment of pain immediately follows the primary survey and should be hourly thereafter. Improvement or deterioration can be monitored using a numerical (for example 0 - 10) or visual analogue scale (Figure 0701). An increasing pain score despite treatment, can be the first indication that the casualty is developing complications and should cause you to re-examine them.

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This analgesic protocol summarises A – Clear casualty airway the principles of B – RR > 8- 10/min? C – Palpable radial pulse? acute pain D – AVPU: A or V ? management in the field. Unless YES NO contraindicated: No analgesia. Entonox can be In pain ? Urgent resuscitation, then reassess used at any stage for rapid, short-term Assess pain score initially, then hourly pain relief. Is pain better or worse since last assesment? i.v. morphine works rapidly and may be given by trained 0 1 2 3 4 5 6 7 8 9 10 personnel titerating dose against effect. Paracetamol 1g If ABCD satisfactory and in pain, every 4-6 hours give morphine 10-20mg i.m. Most i.m. and oral max 4g daily initially and then 10mg 2hrly preparations take =10-30 minutes ±Ibuprofen 400mg every 6 - 8. hours to work. Adding ibuprofen enhances the Fig 0701 Basic approach to battlefield analgesia. analgesic effect and may reduce morphine Considerations requirement. 0705 Use of pain relieving drugs will depend on a number of factors: Logistic • What drugs are available? • Stocks of necessary equipment e.g., syringes and needles. • The number of casualties requiring treatment. • Tactical situation. Casualty • Contraindications to a drug's use e.g., allergy. • The clinical condition of the casualty, in particular, the presence of shock or respiratory distress. 117 Chapter_7.qxd 28/09/2004 15:55 Page 118 7: Analgesia in Forward Areas

• Whether the casualty is about to undergo general anaesthesia and surgery. Personnel • The level of care and monitoring available. • The skill, experience and training of the person administering the drug. • The legal entitlement of the medical or nursing personnel to use a particular drug.

Severe pain

Morphine sulphate 0706 Morphine Sulphate is the gold standard The most feared side effects from the analgesic for moderate to severe pain in the field. use of morphine Acting on opiate receptors, morphine influences pain in the field transmission within the spinal cord and perception of are respiratory pain in the brain. This results in analgesia, anxiolysis, depression and vasodilation in the mood elevation and a degree of sedation. under-resuscitated casualty, resulting in 0707 Morphine can be administered at the point worsening of wounding using the Medimech Auto Injector hypotension. device. It contains 10mg of the drug and is designed for injection through the casualty's clothing deep into muscle. The preferred site is the upper outer Injecting into the quadrant of the buttock on the uninjured side. lateral thigh risks damaging the lateral This can be done by the casualty, a buddy or a medic cutaneous nerve. administering first aid. An 'M' should be drawn on the casualty's forehead along with the time the drug was given. It usually starts to work after 10-30 minutes, but the peak effect is later. A further dose may need to be given after 30 minutes. Subsequently, no more morphine should be administered until the casualty has been reviewed by a medical officer. A medic is allowed to give further 10mg injections every two hours, providing that certain physiological criteria are met (Figure 0701). This approach is equally applicable at Role 1 or Role 4. 118 Chapter_7.qxd 28/09/2004 15:55 Page 119 7: Analgesia in Forward Areas

0708 Intramuscular morphine has the advantages Age is a good of not requiring qualified staff and a more sustained, predictor of if less predictable effect, than i.v. morphine. In the total morphine cold or shocked casualty, morphine can linger in requirement during poorly perfused muscle until warming and the first 24-48 hour period. Casualties resuscitation allows absorption into the blood. >20 years of age If several doses have been given and are usually need 100 mg simultaneously washed out of the muscle, per 24 hours minus this can lead to a relative overdose. their age in years. For example, the 0709 Morphine is available in ampoules of 10 approximate dose for a 20 year old soldier or 15mg which may be given i.m. or i.v. Intravenous would be 100 mg morphine has the advantage of a rapid response. minus 20 = 80 mg of Dilute 10mg with 0.9% saline to give a volume of morphine in divided 10ml (1mg morphine = 1ml). In the resuscitated adult doses. give an initial slow i.v. injection of 5 mg of morphine followed by boluses of 1 to 2 mg according to pain control, heart rate and BP. Continuous i.v. infusions of morphine and Patient Controlled Analgesia (PCA) devices, are available at Role 3.

0710 Antiemetics These will frequently be necessary where morphine has been used, particularly when the casualty is being transported, as the incidence of vomiting during transfer is significant. The phenothiazines (e.g., prochloperazine 12.5mg i.m.) and metoclopramide (10mg i.v./i.m.), are effective in treating nausea and vomiting caused by drugs but, ineffective in motion sickness. Prior to transfer, motion sickness can be prevented with hyoscine (400mcg s.c./i.m.), cyclizine (50mg i.v./i.m.) or ondansetron (4mg i.v/i.m.).

0711 Naloxone Naloxone antagonises the effects of morphine. Available as a 400 mcg/ml i.v. injection, initial doses are 100-200 mcg, with increments of 100 micrograms every two minutes. Its action is specific but short 119

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lived and the reappearance of respiratory depression after 1 hour is a possibility. The duration of action of naloxone can be prolonged by giving additional doses i.m. Side effects include: nausea, tachycardia and hypotension. Analgesia will also usually be reversed.

0712 Side effects of morphine These include: • Drowsiness. • Nausea and vomiting (common). • Hypotension (due to histamine release and vasodilation). • Respiratory depression (rare when pain is still present).

Do not withhold • Constriction of pupils. morphine because of fears of addiction: • Constipation. Casualties do not develop dependence 0713 Contraindications when morphine is used to treat Morphine should not be given to: acute pain. • An unconscious casualty. • Respiratory depression i.e., respiratory rate <8-10/minute. • Hypotension (systolic BP <90mmHg).

Ketamine hydrochloride 0714 In sub-anaesthetic doses (adults 0.5mg/kg), ketamine can be used to provide analgesia for potentially painful procedures. Examples include: redressing burns, manipulation of fractures or the extrication of a trapped casualty. Advantages are: • Powerful dissociative analgesia. 120 • Sedation. Chapter_7.qxd 28/09/2004 15:55 Page 121 7: Analgesia in Forward Areas

• A wider margin of safety than other anaesthetic agents. • Possible to titrate dose against response. • Short acting (5-10 minutes). • Laryngo-pharyngeal reflexes tend to be preserved and the airway maintained better than with other anaesthetic agents (NB: not guaranteed). • Stimulates the cardiovascular system resulting in maintenance of cardiac output and BP (although both may fall in the shocked casualty).

0715 Side effects of ketamine • Transient psychosis/hallucinations. These NB: Use of symptoms occur in the recovery phase and benzodiazepines are more common with high doses or repeated increases the administration. They can usually be prevented risk of airway by small doses of a benzodiazepine compromise and cardiovascular (e.g., midazolam 1-2mg i.v.). suppression. • Nausea and vomiting. • Salivation (may need suction). • Respiratory depression (more likely to occur if morphine or other sedative drugs have been given). • Increased intracranial pressure following head injury. In ventilated casualties, where blood CO2 levels can be controlled, this is less of a problem. • Increased intraocular pressure.

Entonox™ 0716 This is a safe and effective analgesic gas which, when inhaled, enters the circulation, crosses the blood/brain barrier and produces a central effect. It is composed of 50% nitrous oxide (weak anaesthetic agent) and 50% oxygen. 121

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0717 Entonox is primarily used for pain relief at the scene of an incident and when manipulating and splinting fractures. Give Entonox for at least two minutes before attempting treatment (NB: it takes on average two to five minutes to take effect, but may be as long as 10 minutes).

0718 Explain the purpose of the gas mixture to the casualty and how to use the mask. Suitable candidates must be fully conscious, capable of understanding what is being offered and not have any airway or breathing problems. The very young or very old may have difficulty in correct mask fitting and require assistance. Reassure the casualty about the possibility of nausea or drowsiness.

0719 Because the mixture will separate below o 6 C with oxygen on the top and nitrous oxide below, o cylinders should be stored above 10 C. Alternatively, o rewarm by immersing the cylinder in water at 37 C for five minutes then invert several times to mix the gases. Size D cylinders allow 20 - 30 minutes continuous use.

0720 Special features include: • Self-administered on demand by the casualty inhaling deeply through a hand-held mask connected via a demand valve to the gas cylinder. • Inhalation of excess Entonox is prevented by the casualty becoming drowsy and releasing the mask. • Minimal side effects. • Analgesic effect rapidly reverses.

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• Head injuries (see 0737) • Chest injuries (see 0738) • Intoxication - Entonox increases the depressant effects of alcohol, morphine and/or illicit drugs. • Mental Illness or psychiatric disturbances - The casualty may not understand instructions or become distressed or violent.

0722 Contraindications In casualties from diving injuries nitrous oxide will increase the size of the nitrogen bubbles that come out of solution in large joints (‘the bends’), in the spinal cord (‘the staggers’), in the lungs (‘the chokes’) and in the skin (‘the creeps’).

Mild to moderate pain

Codeine phosphate Oral analgesia is of limited value in 0723 Codeine is a weak opioid analgesic battlefield injuries. available for oral or i.m. use (15 mg every 2 hour, Its effectiveness or 30mg every 4 hours to a maximum of 240mg). depends, in part, on gut motility and It is useful in the management of mild to moderate absorption; both can pain, particularly after head injuries or neurosurgery. be delayed by injury and shock. Compound analgesic preparations 0724 Oral preparations combining paracetamol Compound preparations have and one of the weaker opioid analgesics such as little advantage over codeine, dihydrocodeine and dextropropoxyphene, paracetamol alone are available for the treatment of moderate pain. and can produce the These may be useful in postoperative casualties or full range of opiate side effects, in those with minor fractures or soft tissue injuries. including nausea, vomiting, drowsiness Non-steroidal anti-inflammatory drugs (NSAIDs) and respiratory depression. 0725 NSAIDs act on the pain chemicals released at the site of injury. Ibuprofen (400mgs 4-6hourly; max 2.4g daily), diclofenac and ketorolac, are available in oral, rectal and injectable preparations. 123 Chapter_7.qxd 28/09/2004 15:55 Page 124 7: Analgesia in Forward Areas

Adding ibuprofen They have a place in the management of soft tissue can reduce the need for morphine by injuries, minor fractures and postoperative pain, 20-50% and improve either in isolation or in combination the quality “balanced analgesia”. of analgesia. The antiplatelet 0726 Contraindications to the use of NSAIDs effect of ibuprofen include: results in a small increase in wound • Severe asthma, especially if sensitive to aspirin. bleeding which is rarely of clinical • Where there is a threat of reduced renal importance. perfusion, as in shock or dehydration. • Active haemorrhage, in the anticoagulated casualty or a history of peptic ulceration/ cerebral bleeding. A new class of selective NSAIDs (COX-2 inhibitors) are available which may have fewer side effects.

Paracetamol Using several types of analgesia 0727 This is a simple analgesic and antipyretic. together, such as Side effects are rare. The usual dose in adults is morphine, ibuprofen and a local nerve 2 tablets (1g) 4-6hourly. Because of the risk of liver block, can produce damage, the casualty should ideally not receive more superior pain control. than eight tablets per day (4g/day). This is referred to as "balanced analgesia". Local analgesia 0728 The infiltration of local anaesthetics around a wound or the use of nerve blocks, can significantly reduce pain in the pre- or post-operative periods and decrease the casualty's requirement for morphine. Local anaesthetic blocks can provide safe and effective analgesia in acute trauma. The most commonly used agents are lignocaine and bupivicaine. There are a number of limitations in field conditions: • Wounds do not respect anatomical boundaries and may be multiple; the chance of treating the casualty's pain by the exclusive use of local 124 anaesthetics is slim. Chapter_7.qxd 28/09/2004 15:55 Page 125 7: Analgesia in Forward Areas

• Personnel with appropriate anatomical knowledge and training may not be available. • Preparation of both casualty and materials is usually less than ideal in respect of casualty access and positioning, fluid resuscitation and sterility. • There may be insufficient time to perform and wait for the technique to work. • Inadvertent toxic problems, although rare, will be difficult to manage on scene.

0729 Lignocaine (Lidocaine)

Lignocaine is a rapidly acting local anaesthetic In clinical practice, available in 0.5, 1.0, or 2.0% concentrations, with lignocaine and or without adrenaline. It usually starts to work within bupivicaine are often mixed together two to five minutes and persists for up to 90 minutes. in equal proportions The maximum safe dose (MSD) is 4 mg/kg body in the same syringe weight without, and 6 mg/kg of body weight with, so as to achieve adrenaline. 1% solutions are suitable for most rapid action and prolonged duration infiltration and nerve block techniques. Because (NB: beware of the risk of complications, the use of solutions of MSD). containing adrenaline are best avoided in the field.

0730 Bupivicaine Available concentrations are 0.25% (2.5mg/mL) or 0.5% (5mg/mL). Bupivicaine takes five to 30 minutes to work, but lasts up to 12 hours. The MSD of bupivicaine is 2mg/kg (up to 60ml of 0.25%, or 30mL of 0.5%).

0731 Safety This is maximised by • Inserting an i.v. cannula to allow rapid fluid resuscitation and treatment of allergic and toxic reactions. • Always draw back on the syringe before injecting to avoid accidental i.v. injection. 125 Chapter_7.qxd 28/09/2004 15:55 Page 126 7: Analgesia in Forward Areas

• do not exceed the MSD relevant for nerve block and infiltration techniques.

0732 Regional techniques such as spinal and epidural analgesia may be used at Role 3 or Role 4 (see 2524 - 2525)

0733 Topical analgesia is useful in eye injuries (Table 1702) and for urethral catheterisation.

Specific blocks 0734 Femoral nerve block Inject 10 to 15 ml of a mixture of 1% lignocaine and 0.5% bupivicaine just below the inguinal ligament at a site 1.5 cm lateral to the femoral artery (Figure 0702). Aspirate the syringe before injecting to check the artery has not been punctured. The block will onset in 5 to 15 minutes and last up to 12 hour. It provides good analgesia for femoral shaft fractures, allowing them to be reduced and splinted. If necessary, this block can be used in combination with morphine or ketamine.

0735 Haematoma block for reduction of closed wrist fractures This is useful when dealing with a large number of casualties. Attention to sterile technique is important to avoid infecting the haematoma. Adrenaline containing solutions should not be used. Inject 15 ml of a mixture of 1% lignocaine and 0.5% bupivicaine into the haematoma at the fracture site. The block will take effect in about 5 minutes and last about 12 hours.

0736 Intercostal nerve blocks and pleural anaesthesia Intercostal blocks are used to treat the pain from fractured ribs. They are also useful when placing 126

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Ingulnal ligament Femoral nerve Femoral artery Femoral vein

Fig 0702 Performing a femoral nerve block.

chest drains in alert casualties. The practical danger is the risk of pneumothorax. Using short, small gauge needles will reduce the risk. Palpate the rib to be blocked in the posterior axillary line. If the rib cannot be palpated - do not attempt the block. Insert the needle through the skin until it hits bone close to the lower margin of the rib (Figure 0703). When the needle contacts bone, slowly move it downwards until it just slips under the lower margin of the rib. Aspirate the syringe checking for absence of air and blood. Inject 5ml of a mixture of 1% lignocaine and 0.5% bupivicaine. Good analgesia will usually require additional blocks at one or two levels above and below the fracture(s). Following thoracic trauma, pain is often due to injury to the sensitive pleura. If a chest drain has been inserted this can be used to introduce 15mL of 0.5% bupivicaine into the pleural space. Afterwards, clamp the drain for 5 minutes to allow the drug to take effect. Observe the casualty during this period.

127

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Intercostal vein

Intercostal artery

Intercostal nerve

Fig 0703 Performing intercostal nerve blocks.

Clinical Problems

Analgesia in head injury 0737 Untreated pain may cause a rise in intracranial pressure which, in turn, can worsen a developing brain injury. Excess use of morphine will cause respiratory depression (with hypoxia and hypercapnia) and make pupillary assessment unreliable (1612). Pain management in the head injured military casualty is a balance between treating pain and masking an injury requiring neurosurgical intervention. • The casualty in coma after resuscitation is assumed not to be feeling pain. • Headache in the casualty with minor/moderate Severe headache associated with head injury is treated with either paracetamol, vomiting or NSAIDs or codeine phosphate. neurological deterioration, • Pain due to other injuries is treated with may indicate a combination of nerve blocks, paracetamol and an intracranial NSAIDs. Ideally, morphine, if needed, is given haematoma (1625). as incremental i.v. doses (0709). Level of consciousness and cardiorespiratory state need careful monitoring. 128

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• In a casualty with a fractured skull, the nitrous oxide in Entonox coming out of solution (see 0739) could increase the size of an intracranial air collection (pneumocephalus). This may cause deteriorating CNS signs. Practically, casualties with a serious head injury are unlikely to be able to self administer Entonox. In those with mild concussion and pain from other injuries, Entonox should be safe, particularly as the gas is only likely to be given over a short period of time.

Analgesia for casualties with chest injury 0738 Fractured ribs and other chest injuries are very painful. The act of breathing moves the broken ribs making the pain worse. The casualty is reluctant to take effective breaths and to cough. This results in retained secretions, atelectasis, poor oxygenation and carbon dioxide retention. Infection and respiratory failure may follow. Treat chest injuries with a combination of intercostal blocks, paracetamol or NSAIDs and incremental i.v. morphine, depending on effect and the changing clinical picture. At Role 3 or 4, management may include physiotherapy and epidural or intrapleural blocks. The casualty presenting in respiratory failure needs ventilatory support and management in a field ITU.

Entonox and chest injury 0739 Nitrous oxide is 35 times more soluble than nitrogen. It readily diffuses into air-filled spaces faster than nitrogen can be removed, causing increases in pressure and volume. In a casualty with a pneumothorax, the nitrous oxide in Entonox increases the size of the air collection and may even cause it to tension. A functioning chest drain must be in place before Entonox is used.

Mass casualties

0740 The provision of effective analgesia for 129

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mass casualties needs to be simple in its scope and application, supporting the principle of providing the greatest good for the greatest number. Following triage and resuscitation, administration of intramuscular analgesics is likely to be the most practical approach, particularly if personnel lack i.v. injection and cannulation skills and resources are limited. Large numbers of casualties with minor injuries can be given oral analgesia. The monitoring of such casualties may need to rely on minimally trained personnel using simple clinical parameters.

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Infections, Antibiotics and Biological Weapons

Introduction

0801 Despite the best efforts of man, battle injury has never been the greatest cause of death and injury during warfare. That distinction falls to infectious disease, accounting for up to 10 times the number of trauma casualties. An example is the American Civil War, which remains the single greatest loss of life by American Forces in combat - infectious disease accounted for three quarters of casualties and two thirds of deaths.

0802 Most infectious diseases of military significance are transmitted by direct person-to-person contact, faecal-oral spread, or by arthropod vectors. The importance of secondary infections of both battle trauma and subsequent surgical wounds, has long been recognised. One of Florence Nightingale's observations at Scutari was the apparent futility of military medical care: injured soldiers would be saved by heroic surgery in the field, only to succumb several days later to wound infections acquired in the squalid hospitals. Around the same time, Ignaz Semmelweiss demonstrated the importance of hand washing on post-operative infection rates. Changes in management brought about by such observations, formed the basics of infection control and present-day surgical techniques.

0803 The history of using biological agents to achieve military advantage ranges from the simple 131 Chapter_8.qxd 28/09/2004 15:55 Page 132 8: Infections, Antibiotics and Biological Weapons.

smearing of spears with faeces in order to induce wound infection, to the use of toxins such as ricin applied to modern munitions.

Back to Basics - War surgery and infection

Antibiotics do not 0804 The fundamental principles of much battle eliminate bacteria from contaminated surgery are based on reducing the risk of subsequent wounds, but merely wound infection. These include: delay the speed of onset of • Primary surgery to remove foreign bodies clinical infection. - that may act as foci for infection - and dead Their use in the field and dying tissue that provide a bacterial is complimentary to growth medium. immediate and definitive surgery. • Prophylactic antibiotics to reduce rates of bacteria multiplication in compromised tissues. • Aseptic technique reduces further bacterial contamination of wounds. NB: this may not always be important in wounds heavily contaminated by extraneous material and the casualty's own microflora, and not The single, always practicable. most important means of reducing • Infection control to reduce post-operative post-operative contamination of wounds by bacteria from rates of infection is hand hygiene, even elsewhere on the casualty, other casualties on the battlefield. or medical attendants.

Battle Trauma and Infection

0805 In elective surgical wounds, infection rates for many procedures can be reduced to <5%. In contrast, battlefield injuries are prone to develop infections, either de novo or following surgery. Contributing factors include: • Breach of skin and exposure of underlying tissues to microorganisms. 132

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• Implanted foreign matter. • Tissue necrosis due to penetrating and blunt trauma, impaired blood supply, burns or chemicals. • Penetration of hollow viscera releasing large numbers of microorganisms into previously sterile areas. • Delays in primary or definitive surgical intervention. • Deliberate contamination by an aggressor (0803).

Microbiology of War Wounds

Infection control 0806 One of the few joys that a microbiologist is an integral part has is the taunting of surgeons, either by discovering of good surgical new bacteria or by changing the names of existing practice. ones. In reality, there are few pathogens of importance to be aware of, and even these vary in their degree of significance. A rule of thumb in assessing surgical infections is to treat the casualty rather than the microbiology results! Clinical judgement will usually determine if a wound is clinically infected. Bacteria are said to colonise sites from which they were previously absent - infection, by definition, implies a disease process. It follows that there is little to be gained by "routine" sampling of normal wounds - treatment would only be indicated if infection was present. The main reason for knowing something about the microbiology of war wounds is to allow the clinician to make an informed and rational selection of antibiotic treatment when infection occurs. In practice, pathogens are grouped according to the site and nature of the injury; this can be used to determine therapy.

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0807 Simple skin penetration or laceration, with or without environmental contamination Likely organisms: • Conventional pathogens. • Aerobic organisms (grow well in the presence of oxygen). • From the casualty's skin Staphylococcus aureus, less commonly Streptococcus pyogenes. • environmental origin - Bacillus cereus.

0808 Wounds with necrotic tissue or poor perfusion, with or without environmental contamination Likely organisms: • conventional pathogens. • anaerobic organisms (grow well in the absence of oxygen). • Originating from the casualty's skin anaerobic cocci (Peptococcus species, Peptostreptococcus species). • Environmental origin Clostridium species (such as Cl. tetani, Cl. perfringens, Cl. septicum). • Often mixed infections with simple aerobic organisms.

0809 Wounds involving perforation of a viscus (usually gut) Likely organisms: • Conventional pathogens. • Usually mixed aerobic and anaerobic organisms.

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• Gut origin. • Aerobic Gram-negative bacilli (Escherichia coli, Klebsiella species, Proteus species). • Anaerobic gut bacilli (Bacteroides fragilis).

0810 Post-operative infection Likely organisms • Often hospital-associated infection. Contributory factors include: • Infected and highly susceptible casualties concentrated together. • Most casualties will be taking or have taken antibiotics. • Sub-optimal control of infection practices in field conditions. • Types of organism encountered are varied and sometimes unexpected.

Utility of Laboratory Support

0811 Basic microbiology investigations are not essential in forward locations, since the range and sensitivity patterns of organisms involved is largely limited. In addition, casualties are likely to be transferred before any culture results are available (usually at 24 - 48 hours post-sampling). In a more static location, the laboratory will provide: • Organism identification. • Organism sensitivity patterns.

0812 In a large, static facility, microbiological laboratory studies will allow: • Identification of infections due to sensitive organisms. This allows tailoring of treatment to a specific antibiotic or to investigate possible 135 Chapter_8.qxd 28/09/2004 15:55 Page 136 8: Infections, Antibiotics and Biological Weapons.

surgical reasons for persistence of an infection The appearance of drug resistance (e.g., a foreign body, abscess), is important even • Identification of infections due to resistant in field conditions. In some organisms, allowing change to an circumstances, appropriate antibiotic, a facility may be forced to close to • Identification of clusters of infection in parts new admissions, to of the hospital due to similar organisms. Also, stop or delay identification of organisms causing infections surgery, or be unable to transfer infected in staff (e.g., Streptococcus pyogenes), casualties. · monitoring of antibiotic resistance patterns (such as multi-drug resistant Klebsiella species, methicillin-resistant Staphylococcus aureus -MRSA).

Antibiotic Use

Principles of treatment 0813 The basics of antibiotic use are the same regardless of clinical situation or location. Any antibiotic should be given: • Only when indicated and not when unnecessary. • Ideally target the organism i.e., have a narrow spectrum of action. • By the appropriate route i.e., in serious infection this is i.v. • In a large enough dose; underdosing is common. • To reach the target area. Some antibiotics do not pass into urine, bile or CSF. • For long enough. i.e., until the clinical condition resolves. • Then: be stopped when extended use is of no value.

136

Antibiotics following Maxillofacial Injury: see 1819 Chapter_8.qxd 28/09/2004 15:55 Page 137 8: Infections, Antibiotics and Biological Weapons. Battlefield considerations 0814 These include: • Antibiotics buy time to surgery but are not an alternative. • Injectable drugs are more reliably absorbed. • Antibiotics may need to be given by non-Medical Officers. • Simple regimens are easier to pre-position in forward locations. • Narrow spectrum drugs will cover most common pathogens and make subsequent choices of antibiotics in hospital easier.

Choice of antibiotics 0815 Knowledge of the basic microbiology of battle trauma allows a rational choice of antibiotics to be made according to a clinical assessment of a wound:

0816 Limb, soft tissue and muscle injuries (pre-surgery). Likely organisms are Staphylococcus species, Streptococcus species or simple anaerobic organisms. Most are sensitive to penicillin. Give: benzyl penicillin 1.2 g as a single i.m. dose (ideally, within 1 hour of wounding).

0817 Perforating wound of gut or other hollow viscus. Organisms are likely to be mixed aerobes and anaerobes of gut origin. Most will be penicillin resistant. Suitable antibiotics: co-amoxyclav (Augmentin™) 1g as a single i.v. dose or ceftriaxone (Rocephin™) 1g as a single i.v. dose plus metronidazole (Flagyl™) 500 mg as a single i.v. dose. Ceftriaxone can be given by non-medical staff by deep i.m. injection. 137

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0818 Open head injury. Organisms are likely to be aerobes. Consider anaerobes (and possible subsequent brain abscess) if there is a breach of the air sinuses or the middle ear. Antibiotics must penetrate the blood-brain barrier. Suitable choices are: ceftriaxone (Rocephin™) 1 g as a single i.v. dose or, if there is sinus/middle ear involvement: ceftriaxone (Rocephin™) 1 g plus metronidazole (Flagyl™) 500 mg as a single i.v. dose.

0819 Hospital-acquired infection. Because of the wide range of organisms and likelihood of drug resistance, seek microbiology guidance

0820 Urinary tract infection. Uncomplicated infection is commonly due to Escherichia coli and similar organisms. A suitable antibiotic is: trimethoprim 200mg twice daily orally for 7 days. Complicated infection may be due to any organism (including drug resistant species). A suitable antibiotic is: ciprofloxacin (Ciproxin™) 250mg twice daily orally for 7 days (i.v. if evidence of systemic disease).

0821 Lower respiratory tract infection. Uncomplicated infection is commonly due to Streptococcus pneumoniae. A suitable antibiotic is: co-amoxyclav (Augmentin™) 500mg orally three times daily for 7 days. Complicated infection may be due to any organism (including drug resistant species). A suitable antibiotic is ceftriaxone (Rocephin™) 1g i.v. once daily until resolved. Consider adding clarithromycin (Klaricid™) 500mg i.v. twice daily.

0822 Wound infection. This is usually due to Staphylococcus aureus, less commonly Streptococcus pyogenes. In civilian hospitals, 138 Staphylococcus aureus is usually resistant to

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penicillin. Resistance is less of a problem in field hospitals where the operating theatres, at least initially, are unlikely to be colonised by penicillin resistant bacteria. A suitable antibiotic for penicillin resistance is: flucloxacillin 500mg orally four times daily for seven days (i.v. if there is evidence of severe disease).

Penicillin allergy 0823 True penicillin allergy (anaphylaxis) is rare. (0.05%) Most reactions are minor ones, e.g. transient rashes, nausea and gastrointestinal upset. In life-threatening infections, such events should not be a contraindication to treatment. Of those individuals with true anaphylactic reactions, only about 15% have cross-reaction to cephalosporins. For severe illness where a penicillin-type drug is required give: cefuroxime (Zinacef™) 750 mg i.v. three times daily. For less severe illness, a different class of antibiotic could be used e.g. ciprofloxacin (Ciproxin™) 250mg twice daily orally for 7 days or clarithromycin (Klaricid™) 250mg orally twice daily for 7 days.

Specific Conditions Related to the Battlefield

0824 A number of infective complications are traditionally associated with battlefield injuries. Accurate microbiology in recent years has enabled the underlying pathogens to be identified. With few exceptions, the clinical diagnoses are characteristic. Whilst antibiotics may reduce some of the local effects and delay systemic spread of infection, definitive treatment is usually surgery.

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Because the toxin is The cause is Clostridium tetani, a widely distributed non-immunogenic, spore-forming organism, present in greatest numbers clinical infection does not provide where human or animal faeces are to be found. natural immunity to Sporulation requires an anaerobic environment. re-infection: immunisation Once inoculated into tissues, the incubation period with altered toxin is up to 7 days. Local and systemic effects are due ("toxoid") is required to release of toxin. (0828). 0826 Clinical features These include: • Muscle stiffness e.g., masseter muscles (trismus or “lockjaw”), facial muscles (risus sardonicus), limbs and thorax. • Muscle spasm, often painful and typically triggered by mild stimuli. • Death associated with respiratory impairment or unstable cardiovascular system.

0827 Treatment Principles of treatment are based on the disease pathogenesis and include: • Medical management (ventilatory support, stabilisation of cardiovascular system, antispasmodics). • Elimination of circulating toxin by human tetanus immunoglobulin (5,000-10,000 units i.v.). • Removal of the source of toxin (usually surgical with a secondary role for antibiotics), prevention of recurrence (0828).

0828 Prevention Prevention is easier than cure. 140

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• Immunise with tetanus vaccine (0.5ml i.m.) followed by further doses at 4 and 8 weeks. Give a booster dose every 10 years (NB: all UK military personnel should be covered). • Non-immunised battlefield casualties: perform wound excision; start immunisation (see above), give human tetanus immunoglobulin (250-500 units i.m.) and antibiotics (0816).

"Gas gangrene" 0829 Pathophysiology Caused by spore-forming organisms related to Clostridium tetani (0825), of which Clostridium perfringens is the commonest. Once inoculated into anaerobic tissues, the incubation period is usually 48 hours or less. Wounds prone to Clostridium perfringens infection tend to be deep, necrotic, avascular and often associated with the presence of foreign bodies. Clinical features are caused by a variety of toxins, producing both severe local reactions (myonecrosis and gas production in tissues) and systemic effects.

0830 Clinical features Local: severe pain, intramuscular and subcutaneous gas, extensive tissue necrosis. Systemic: cardiovascular collapse, renal failure, intravascular haemolysis.

0831 Treatment This is based on first principles: • Medical management - resuscitation, antibiotics (limited role). • Surgery - excision of all necrotic tissue. • Adjuncts - hyperbaric oxygen therapy can be of benefit but, is not practical for the battlefield. 141

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Antitoxin is available in limited supplies but is of minor importance. Human vaccine is unavailable. Disease prevention is by appropriate wound management (0503).

Necrotizing fasciitis 0832 Pathophysiology Necrotizing fasciitis comprises two distinct microbiological aetiologies which produce identical clinical features: • Streptococcus pyogenes alone • A mixture of anaerobic cocci, with or without aerobic organisms (usually Gram-negative bacilli). This is the most common form. The aetiology is important - Streptococcus pyogenes is highly transmissible to both other casualties and staff whereas, the mixed infection, is not. Initial trauma may be trivial. The incubation period is variable. This is followed by a rapidly spreading infection involving subcutaneous tissues. Tracking into muscle is a late event.

0833 Clinical features Signs and symptoms develop rapidly. These include: • Pain and tenderness; erythema with a poorly demarcated edge. Loss of sensation in the affected area is a late, characteristic complication. Gas in tissues commonly occurs with the mixed infection group. • Systemic toxaemia is common and out of proportion to local symptoms.

0834 Treatment • Medical management - resuscitation. Antibiotics 142 are of minor importance (0816). In the absence Chapter_8.qxd 28/09/2004 15:55 Page 143 8: Infections, Antibiotics and Biological Weapons.

of microbiology, choice of antibiotics should cover both aerobic and anaerobic organisms. • Surgery - perform early and extensive surgical excision beyond the advancing edge of infection. Amputation is not usually necessary, it is usually sufficient to excise an affected muscle compartment. Delayed surgery or sub-total resection, is associated with a poor outcome. • Adjuncts - hyperbaric oxygen therapy can be of benefit, but is not practical for the battlefield.

Infection Control on the Battlefield

0835 When operating under field conditions, The efforts of heroic it can be tempting to dismiss infection control surgery must not be practices as being of limited benefit. On the contrary, compromised by the subject is of greater importance than in aseptic, sloppy infection civilian environments, since the consequences of control practice. infection are more serious. Measures to prevent spread of infection from the environment, and between casualties and carers, include: The most appropriate • Staff hand hygiene approach will be (reduces post-operative cross-infection). dictated by individual circumstances and • Skin cleansing. will always be a compromise between • Source isolation. the "gold standard" and what is safe. • Occlusive dressings The aim is to (disturb them only when really necessary). develop local practices that are • Use of gloves and operator masks practical and of (the latter are of limited value). maximum benefit. • Air filtration (unlikely to be of benefit in the field). • Clinical waste management, sharps policy (important to prevent blood-borne virus infections).

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Introduction 0836 The term "biological weapon" is applied to any organism or material of biological origin, used with the intention of causing death or disease in a target. A "biological agent" refers to either a micro- organism or a toxin of biological origin (e.g., ricin). For practical purposes, agents are grouped according to their effects - lethal or non-lethal and behaviour in the target population-transmissible or non-transmissible. 0837 Following its initial dissemination by whatever means, the agent behaves in exactly the same manner as naturally-occurring disease. In other words, the management of casualties outside the immediate area of attack, with an illness caused by a specific agent, is no different from that of the "normal" infectious disease.

Likely or possible agents

0838 Anthrax Bacillus anthracis is a Gram positive, spore-forming rod. The disease normally has an incubation period of 1-6 days. There are three forms: Cutaneous: originates from infected livestock. Pustules, which progress to fluid filled vesicles, develop on the hands and forearms. Eventually, these dry to form a black scab. Approximately 25% of local infections progress to a fatal, systemic infection. Gastrointestinal: is rare and is secondary to eating infected meat; it carries a 100% mortality. Inhalational (Woolsorter's disease): is due to inhalation of spores. Initial symptoms are: fever, malaise, fatigue, cough and chest discomfort, 144 progressing to severe respiratory distress and shock. Death generally occurs within 24-36 hours. Chapter_8.qxd 28/09/2004 15:55 Page 145 8: Infections, Antibiotics and Biological Weapons.

The organism can be detected by Gram-staining of blood and by blood cultures. Treatment, including supportive measures and high dose antibiotics (penicillin, ciprofloxacin or doxycycline), is of limited effectiveness. Prophylaxis is by anthrax vaccination and administration of ciprofloxacin or doxycycline to those who may have been exposed. Mortality in established disease is close to 100%.

0839 Plague The causative organism is Yersinia pestis, a transmissible, Gram-negative organism. Three forms occur in man. 1. Bubonic plague: is spread by fleas from infected rodents. After an incubation period of 2-10 days, the casualty develops a high fever, malaise, abdominal pain and painful lymphadenopathy. Because the fleas tend to bite the lower limbs, nodes in the groin are particularly affected (buboes). There may be hepato-splenomegaly Approximately 25% progress to the septicaemic form. 2. Septicaemic form: features are similar to other Gram-negative septicaemias and may progress to shock, thrombosis and DIC. 3. Pneumonic plague: is an infection of the lungs, either due to inhalation - primary (incubation period 1-6 days) or, rarely secondary to septicaemia. In biological warfare, the organism is likely to be disseminated as an aerosol. Clinical features include: acute onset of pyrexia, malaise and respiratory distress, classically accompanied by haemoptysis. Gastrointestinal symptoms are often present. Death is due to respiratory failure, circulatory collapse and a bleeding diathesis.

145

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Suspect the diagnosis if a group of previously healthy service personnel or casualties develop Gram-negative pneumonia. The diagnosis can be confirmed from Gram-stain of sputum, CSF or lymph node aspirate and by blood culture. Early administration of ciprofloxacin, doxycycline or gentamicin is essential; delay is invariably fatal. Prophylaxis for those at risk is with doxycycline. No effective vaccine is currently available.

0840 Botulinum toxin Botulism is caused by a group of neurotoxins produced by the spore-forming bacillus Clostridium botulinum. These neurotoxins are the most potent known to man (weight for weight 15,000 times more lethal than VX; 100,000 times more lethal than Sarin), even at small doses. Deaths continue to occur due to ingestion of contaminated food. The toxin can be dried and is most likely to be administered by an aerosol attack. Symptoms usually begin 12-36 hours after exposure, with paralysis of the cranial nerves (ptosis, blurred vision, diplopia, dry mouth, dysphagia and dysphonia). This is followed by symmetrical, descending flaccid paralysis with generalised weakness and progression to respiratory failure. Diagnosis is clinical. Treatment is supportive. An antitoxin is available.

0841 Smallpox The causative organism is an orthopox virus (variola major and minor). It is an attractive biological weapon because: • It is relatively easy to manufacture. • Can be administered by an aerosol. • Is transmissible. • Immunity across the population is now 146 relatively low.

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• There is no effective chemotherapy. After an incubation period of 7-19 days, there is acute onset of malaise, fever, rigors, vomiting, headache and backache. Approximately 2-3 days later, macules appear on the face, hands and arms; these progress to papules and eventually to distinctive vesicles. Diagnosis is clinical and treatment supportive. Smallpox can be prevented by vaccination. Mortality in unvaccinated casualties is 30%.

Battlefield considerations 0842 What is the target? • Military personnel: may be protected by IPE (0228), vaccines and antibiotics. • Civilians: are usually easier targets than military personnel. • Animals and plants: with the aim of compromising the food supply and logistic infrastructure. • Environment: employing organisms currently available which can degrade organic materials (such as crude oil and hydraulic fluids).

0843 What is the strategy?

• Death or incapacitation? The latter may be Greater resources more effective. are required to nurse the sick than bury • Individual or tactical targeting e.g., assassination the dead! or targeting of small, mission-essential groups on the battlefield. • Operational e.g., attack against one functional sector of an operational theatre, or a logistic "choke point", such as a key airfield. • Strategic e.g., to affect an entire operational theatre or, the use of a non-deniable organism, such as smallpox. 147 Chapter_8.qxd 28/09/2004 15:55 Page 148 8: Infections, Antibiotics and Biological Weapons.

• Terror i.e., psychological warfare ("PSYOPS"). . • Bluff i.e., take advantage of disease control measures likely to be employed by an opponent, such as quarantine and cessation of offensive operations.

0844 What is the impact on Field Surgery? • All members of the surgical team need to be individually protected against likely agents (vaccination, antibiotics, IPE). • Forward surgical teams may need to operate in areas of collective protection This can be problematic, in terms of its efficacy, when biological agents have been used. It can also severely reduce casualty throughput. • Casualties require decontamination before medical treatment (NB, chemical agents may also have been used). • All infectious diseases (natural or unnatural) have an incubation period - any casualty operated on could subsequently develop symptoms up to 3 weeks after exposure. • Because of their contact with casualties, it is likely that the first indications of a covert biological attack will be seen in medical units. Concentration of casualties and medical personnel will allow rapid spread of transmissible agents, unless infection control practices are enforced.

• The critical nature of medical support units means that they become an attractive target for an aggressor - loss of such a unit will cause a disproportionate impact on offensive operations.

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0845 What actions can be taken? The effect of deliberately releasing • Rapid communication of medical suspicions to biological agents on the command chain. field surgical units can be reduced by • Application of infection control precautions at all high standards of clinical practice. times, with "source isolation" when suspected cases are identified. • Sample collection. Samples are required for: • Clinical diagnosis - "quick and dirty" to allow effective treatment to be given. • Forensic - "slow time" with a detailed chain of custody, for use in later legal and political actions. Technology changes rapidly and advice on current procedures should be sought through the medical command chain. • Restriction of movement will limit the spread of a transmissible disease. This will be a command decision since there are significant implications for force effectiveness. From a medical perspective, this will mean both suspension of resupply, and cessation of all medical evacuation.

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Limb Injuries

Introduction

0901 Limb trauma accounts for 50-70% of all war Ten percent of injuries. The lower limb is more frequently affected battlefield casualties than the upper limb, in a ratio of 2:1. Life-threatening with limb wounds bleed to death injuries include: complete or incomplete traumatic unnecessarily. amputation, multiple long bone fractures and major Do not allow this pelvic injuries. Other wounds can be sufficiently to happen. serious to threaten limb viability. These include: Limb bleeding is compressible or vascular damage, crush injury, compartment controllable by use syndrome and bone and soft tissue sepsis. of a tourniquet. The majority of casualties will have relatively minor To a lesser extent, soft tissue injuries and may be able to walk to find haemorrhage from pelvic fractures is aid or, apply self-aid. Between 35% and 50% of limb also compressible. wounds have bone involvement. Fracture types are illustrated in Figure 0901. In addition to war wounds, deployed service personnel may experience the same range of orthopaedic trauma seen in civilian practice. The management of these injuries is described in the second half of this Chapter.

0902 Differences between military and civilian Delays in managing wounds are discussed in 0501. Features of limb limb wounds are not wounds in war include: usually life- threatening, so • Damaged bone is more likely to communicate most casualties are triaged as T3. with the skin surface resulting in open (compound) fractures (Figure 0902). • They are generally triaged as T3, consequently, delays in transfer mean that the majority of wounds will be infected by the time the casualty reaches a surgical facility.

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AB C DE

A Green stick fracture (children) B Simple transverse fracture C Simple oblique or spiral fracture D Comminuted fracture E Incomplete drill hole and avulsion type fractures F Crush

F

Fig 0901 Fracture types. Fractures can be open or closed depending on whether they communicate with a skin wound.

• Thigh and pelvic wounds may be complicated by spillage of abdominal contents. • Initial treatment is often under field conditions and may take place in the absence of equipment and an orthopaedic surgeon.

Management

Management in the field

0903 Initial management includes: • ABC, with emphasis on arrest of compressible haemorrhage as part of the resuscitation phase of BATLS (0330).

152 • Analgesia.

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Fig 0902 Manual reduction of an open lower leg fracture. The penetrating fragment is repositioned by local pressure.

• Look for long-bone fractures, covert vascular injury (the six ‘Ps’ 1010) and neurological deficit Be suspicious of (2114 - 2117). Note deformity, CRT, skin colour open wounds in and temperature, the presence of peripheral close proximity to a major artery. pulses, cutaneous sensation and active and passive limb movement.

• Correct deformity by manual traction (Fig 0902). 153

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This relieves pain and protects the circulation. Peripheral pulses are A bone fragment poking through the wound palpable in 30% of injured limbs despite should be repositioned by direct pressure. major arterial • Clean and, where feasible, irrigate wounds; trauma.. dress wounds with firm, sterile dressings (0502). • Splint and elevate fractures and extensive soft tissue wounds (0331). If possible, use a traction splint for a fractured femur (Figure 0319) or apply a Thomas splint with a Crookham halter around the boot (Figure 0320). • Give parenteral antibiotics, preferably within one hour of wounding (0816). Consider DVT prophylaxis (0980). • Transfer to a surgical facility.

Management at Role 2 or 3 0904 The principles are: • Restoration of circulation. • Wound excision, for subsequent delayed primary closure. • Fasciotomy if appropriate. • Stabilisation of fractures and major soft tissue injuries. Reduction of dislocations. • Obtaining skin cover.

Restoration of circulation 0905 Following major arterial injury, revascularisation should be achieved within six hours to optimise limb survival.

Compartment syndrome 0906 A rise in pressure in an enclosed body compartment (e.g., a limb, the abdomen), such as to interfere with tissue perfusion, is a ‘compartment 154 syndrome’. Causes include:

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• Tight bandages or plaster cast. • Trauma and surgery. • Arterial injury. • Crushing. • Burns. • Strenuous exercise. In the limb, accumulation of blood and tissue oedema within a muscle compartment surrounded by inelastic fascia, interferes with capillary flow, leading to local muscle ischaemia and tissue necrosis.

0907 The limb is typically swollen, tense and Limb fasciotomy: the tender (NB: if late in onset - consider DVT 0979). commonest causes Peripheral pulses and capillary filling are usually of failure are operative delay and normal distal to the affected compartment(s). Pain is the use of a closed often out of proportion to the injury and may be technique ; this is uncontrollable with morphine. Increasing discomfort insufficient to fully on gently dorsiflexing the toes or fingers of an release all affected tissues. affected limb, can be an early sign. Where pressure monitoring is available, insertion of a pressure probe below the deep fascia, will aid diagnosis.

0908 When a compartment syndrome is suspected, initial treatment is to split any plaster If transfer is delayed, cylinder or circumferential dressing down to skin consider whether 'at level, then open them widely along their complete risk' wounds require fasciotomy in the length. If this does not improve symptoms, rapidly field. Perform under perform a fasciotomy (see under Specific Management). sterile conditions The whole length of the compartment(s) must be (GA or LA). Avoid decompressed. After fasciotomy, the wound is left using a tourniquet. open, dressed with a bulky dressing, splinted and the limb elevated to reduce swelling. Unless obviously necrotic, excision of non-viable muscle is usually deferred until the casualty is reviewed in the operating theatre 2-5 days later. By then, tissue oedema will have partially subsided and the wound can usually be approximated. Any remaining defect 155

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may require application of a split skin graft 7-10 days after fasciotomy.

Wound excision 0909 The majority of military limb wounds require exploration and wound excision under GA or LA (0503).

Principles of stabilisation of fractures and major soft tissue wounds 0910 Radiographs are useful to assess the nature of a limb fracture and plan stabilisation, but are not essential for initial management. Taking radiographs must not delay treatment or transfer.

0911 The majority of fractures and deep or extensive soft tissue wounds, should be splinted. Where there is significant deformity or joint Following penetrating, high dislocation, reduce under GA, i.v. ketamine (0714), energy fractures, Entonox (0716), or nerve block (0734 - 0736). the extent of contamination can Reduction and stabilisation: be estimated from the position of the • Provides pain relief. fragments on X-ray. • Reduces haemorrhage. • Prevents further soft tissue injury. • Reduces the incidence of fat embolism. • Allow some casualties to care for themselves.

0912 The optimal method of splinting a fracture depends on which bone is injured, the wound and the nature of any bone defect. In general, the initial treatment of choice for long bone fractures is application of a plaster of Paris (POP) splint. Because of the direction of pull of attached muscles, femoral fractures tend to result in overriding of the bone ends, an extensive haematoma and limb shortening. Place the limb in a Thomas splint and 156 immobilise it by applying either fixed skeletal (0935)

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or skin traction (0936). Stabilisation during transfer can be improved by conversion to a Tobruk splint (0937).

0913 At Role 3 or 4, a back slab may be converted to a full POP cylinder or another method of immobilisation (e.g., external fixation). Similarly, it may be decided to nurse the casualty with a fractured femur in a Thomas splint with balanced traction or, use intramedullary nailing.

Joint dislocation 0914 Dislocation may complicate a fracture and interfere with reduction. Ideally, obtain a radiograph before treatment. All dislocations should be reduced at the earliest opportunity (for techniques: see ‘Civilian Limb Injury’); Check the circulation and neurological function before and after manipulation. The joint should subsequently be immobilised.

Methods of stabilisation Plaster of Paris (POP) 0915 This is rapid and easy to apply with minimal equipment. It is suitable for most limb soft tissue wounds and fractures. With the exception of the femur, it is the treatment of choice in the initial management of long bone fractures. It can be combined with other external splints. • Apply stockinet (not Tubigrip™) to prevent plaster sticking to the skin and cover this with a Plaster was originally layer of wool padding, particularly over bony developed for use on prominences. Cut a suitable length of full- the battlefield. Encasing the wound thickness plaster and apply this as a backslab in plaster and (Figure 0903A). For major arm and tibial allowing it to heal fractures, the backslab must incorporate the joint was employed above and below the defect and, where extensively during the Spanish Civil necessary supplemented with lateral slabs War with good (Figure 0903B). Wet the POP thoroughly then results (Trueta technique). 157

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A

B

Fig 0903 A) POP back slab for: ankle injury (stockinet and padding omitted for clarity). B) POP back slab for lower leg injury.

squeeze out excess water before application. Mould plaster slabs to the limb until set and hold them in place using a crepe bandage. Ensure the edges and ends of the plaster are smooth and do not dig in. Check the circulation and elevate the limb. In the acute situation, or after initial wound excision, plaster must not be allowed to encircle the limb. • At the second operation, manipulation of the fracture may be required to obtain optimum alignment. By now, swelling should have subsided and the backslab can be converted to a complete cylinder. Mould the POP cast to prevent limb rotation. In civilian practice, lightweight synthetic plaster substitutes are commonly employed. To reduce the risk of developing a compartment syndrome, cylinders may be split down to skin along their complete length (Figure 0904) and the two halves bandaged to the limb. Bi-valve of a POP cylinder is essential 158 prior to lengthy casualty transfer by air.

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• Limited wound access can be achieved by Symptoms of too tight a plaster are creating a plaster window (Figure 0904), but this pain and numbness. may compromise fracture reduction by Check for swelling, weakening the plaster. pulses, CRT and cyanosis. • If the casualty develops numbness or disproportionate pain, consider a compartment syndrome (0906).

Traction 0916 Traction is a simple method of maintaining a satisfactory reduction, especially where orthopaedic experience and resources are limited. It has the advantages of safety and of not interfering with subsequent methods of bone fixation but, may require prolonged bed rest.

External fixation If the casualty has a 0917 Indications for external fixation rather than long bone fracture plaster include: and requires a fasciotomy, the • Unstable fractures with extensive bone loss. fracture must be stabilised by a • Large soft tissue wounds e.g., after fasciotomy. method which allows access to the • Vascular injuries requiring repair. fasciotomy wound i.e., application of an • Fractures associated with burns. external fixator or Thomas splint. • Polytrauma. • To facilitate casualty transfer.

0918 External fixators allow wound access, early mobilisation and discharge but, are technically difficult to apply well in the field. Commom complications include pin site infection and loosening. Fixators must only be used by those with previous experience. Technical points for their use include: • Stab incisions in the skin should be at least 1cm in length.

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Plaster window

Full length plaster cylinder split on both sides

Fig 0904 Completed full leg POP cylinder split on both sides. A 'window' allows wound access.

surface of a bone. Where there is a risk of damaging adjacent structures, use an open technique (e.g., distal humerus, distal radius). • Insert 2-3 pins to hold the main bone ends above and below the fracture (Figure 0905). Additional pins may be required to immobilise major fragments. • Because of the risk of infection and propagating cracks, avoid inserting pins within 2-3 cm of a fracture. • Ensure bicortical pin placement; the pin must pass through the cortex, medullary canal and penetrate the far cortex (Figure 0905). In hard bone, pre-drilling with a 3.2mm drill bit will be necessary with the older type of British military-pattern external fixators. The newer Hoffmann II™ pattern pins are self- drilling and self-tapping. • Ideally, all pins should be connected to the same bar. This can be achieved by inserting the most proximal and distal pins first. These are then connected to a single bar and the fracture reduced as accurately as possible. Further pins can than be inserted by fixing pin-to-bar 160 connectors to the bar and using these as guides.

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Skin and subcutaneous fat

Tibia

Fibula

Fig 0905 External fixation. Note bicortical pin placement.

Generally, a second bar should be used to increase the stability of the frame. • Following fracture reduction, pin wounds should be checked and any tenting of the skin released. The pin wounds are regularly cleaned to prevent crusting and are left exposed to drain.

Internal fixation 0919 This requires appropriate equipment and implants. Internal fixation is technically demanding. It is not available at forward surgical facilities, where its use is inappropriate. It may be required for subsequent, definitive surgery. Disadvantages include an increased risk of infection. 161 chapter_9.qxd 28/09/2004 15:55 Page 162 9: Limb Injuries Obtaining skin cover 0920 Delayed primary closure of military wounds is the norm (0503). If the wound is clean, it is closed by sutures, split skin grafts or soft tissue flaps. Small defects can be left to heal by formation of granulation tissue. Fractures are often manipulated at this stage to obtain a better position and a decision made as to the optimum method of stabilisation during healing.

Crush injuries 0921 Crushing causes tissue ischaemia and may necessitate limb amputation. Depending on the amount of tissue damaged and the duration of entrapment, return of circulation after release can be associated with: • Acidosis and release of intracellular potassium, leading to fatal cardiac arrhythmias. • Severe tissue oedema causing hypovolaemic shock. • Release of mediators of the systemic inflammatory response syndrome (SIRS) resulting in vasodilatation and shock. • Breakdown of muscle tissue and release of myoglobin. The presence of this large molecule in the circulation may cause acute renal failure.

0922 Following a significant crush injury (e.g., whole leg entrapment for >3hours): • Administer high flow oxygen, analgesia and set up an i.v. infusion prior to release.

• Be prepared to administer 2 to 3l of crystalloid quickly to control shock and maintain a urine output of >100ml/hour.

162 • Give 500ml of 10% Mannitol to promote a diuresis.

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• Perform a fasciotomy. Dress the wounds, splint the limb and elevate. • Ideally, the casualty should be connected to a cardiac monitor and observed for arrhythmias in an ITU. • It may be appropriate to manage a severely injured (mangled) limb by application of a tourniquet at scene, followed by amputation after release (1106).

Specific Management of Military Limb Trauma

Upper limb Humerus 0923 Following wound excision, fractures and extensive soft-tissue wounds are initially splinted. • Use a POP back slab extending from the shoulder to the forearm (Figure 0906). Gravity will help pull displaced fractures of the neck and shaft of the humerus into alignment. • A SAM or improvised splint can be similarly effective (Figure 0318). • Provide support using a lesser arm sling, or collar and cuff with the elbow at 90 degrees. Hold the arm in place by bandaging it to chest wall under the casualty’s clothing. • Nurse the casualty sitting up; encourage them to exercise their fingers and wrist.

0924 If the radial pulse is absent, gently moving the elbow may relieve pressure from a bone fragment on the brachial artery and restore flow. Immobilise the limb in this successful position. If the elbow cannot be readily flexed, lay the casualty on a stretcher and strap the arm to their side (Figure 163

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Plaster backslab held in place with crepe bandage

Lesser arm sling

Fig 0906 Hanging back slab and lesser arm sling used to treat a fractured humerus. 0315). Continue to monitor neurovascular function. Transfer to a surgical facility as priority T1.

0925 External fixation of the upper arm is avoided unless there are specific indications (e.g., bone loss, vascular repair, multiple injuries). If external fixation is considered necessary: • Do not insert pins into the proximal humerus because of poor hold and the risk of neurovascular damage (Figure 0907). • Insert pins through the lateral aspect of the shaft avoiding the anteromedial neurovascular bundle. • Insert distal pins laterally using an open approach to prevent damage to the radial nerve. • A bridging fixator, with pins inserted into the distal humerus and the shaft of the ulnar, can be used to treat fractures or severe soft tissue injuries around the elbow joint.

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Avoid pins

Perculaneous insertion of pins

Open insertion of pins

Flexor compartment Humerus

Neurovascular bundle

Pins should be inserted laterally

Extensor compartment

Fig 0907 External fixation of the humerus: sites for pin insertion.

and related muscles and extensor, containing the triceps (Fig 0907). Decompression is rarely required. When considered necessary, perform this through a single, lateral incision.

0927 After transfer to Role 4, treatment using POP or splinting is usually continued. This may be converted to internal or external fixation. 165 chapter_9.qxd 28/09/2004 15:55 Page 166 9: Limb Injuries

Anterior incision Median nerve Flexor carpi radialis Brachioradialis Flexor digitorum Radial superficialis nerve Flexor carpi ulnaris

Ulnar nerve

Flexor Radial digitorum artery profundus Radius Ulna

Extensor Extensor carpi radialis digitorum brevis communis Dorsal incision

Fig 0908 Cross-section of forearm showing approaches to the flexor and extensor compartments.

Forearm 0928 The forearm can be divided into flexor and extensor compartments (Figure 0908). The closely applied neurovascular bundles are easily damaged during wound excision. • Both soft tissue and bony injuries, are treated by application of a POP backslab and elevation in a sling. Once tissue swelling has subsided, this can be converted to a cylinder that includes the wrist. For proximal injuries, the elbow should be incorporated in the plaster. • Unless viability is a problem, vascular injuries in the forearm are unlikely to be repaired at a forward surgical facility (1043). • In casualties with severe soft tissue and bone injuries, primary amputation may be necessary (1120). This usually follows anti-personnel mine injuries, where the device has been handled.

166 0929 External fixation is rarely required. Where

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Fig 0909 Decompression of forearm flexor compartment: 'lazy-S' skin incision and division of deep fascia.

indicated, pins are inserted through the subcutaneous border of the ulna. If it is essential to place a pin into the radius, use only the distal part of the bone and employ an open technique. Internal fixation with plates may be considered at Role 4, together with a bone graft to replace extensive bone loss.

0930 Decompression: • The superficial and deep flexor compartments are approached through a single anterior skin incision beginning proximal to the antecubital fossa and extending to mid-palm (Fig 0909). • Skin flaps are raised and the dissection continued in the interval between flexor carpi ulnaris and flexor digitorum superficialis, so as to expose the median and ulnar nerves and the flexor digitorum profundus (Figure 0908). This allows division of the superficial and deep fascia, as well as release of the carpal tunnel by incision of the transverse carpal ligament. • Where necessary, the approach to the extensor compartment is through a posterior incision in the pronated forearm, beginning 2cm medial and 167

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Fig 0910 Skin incision for decompression of forearm extensor compartment.

2cm distal to the lateral epicondyle (Fig 0910). The incision extends towards the wrist. Skin flaps are raised and the dorsal fascia divided throughout the length of the forearm. Dissection is between extensor carpi radialis brevis and extensor digitorum communis (Figure 0908). In the forearm, incise the fascia over individual muscles.

Hand 0931 Extensive wound excision is not necessary and removal of skin is kept to a minimum. • Skin flaps should be preserved for subsequent closure, even if they appear degloved. • Tendon (Figure 3032) or nerve repair (Figure 2110) is usually inappropriate in the field. • All injuries should be splinted using POP; the optimal position is with the wrist slightly bent back, the metacarpo-phalangeal joints at 90 degrees and the interphalangeal joints extended (Figure 0911).

• The hand is elevated in a high sling (Figure 0317) to reduce swelling and the tips of the fingers left exposed for inspection.

0932 To optimise functional recovery, early 168 transfer to a hand surgeon is indicated. Definitive chapter_9.qxd 28/09/2004 15:55 Page 169 9: Limb Injuries

Fig 0911 Immobilisation position following hand injury.

management may involve the use of K wires, plates and mini external fixators.

0933 Crush injuries can produce carpal tunnel compression and/or a compartment syndrome affecting the interossei, thenar or hypothenar muscles. Treatment is division of the transverse carpal ligament (0930) together with dorsal incisions over the affected muscles (Figure 0912).

Lower limb Pelvic injury See 1304-1309 Femur 0934 Blood loss following a femoral fracture is approximately 1.5-2l (Figure 0303). This may be increased by the presence of extensive, open thigh wounds. Though such casualties may appear stable, there is a risk of sudden deterioration. They require resuscitation, traction splintage and early transfer to 169

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Fig 0912 Hand injury: incisions for interosseus muscle decompression.

a surgical facility. Open traction splints (Figure 0319), are ideal for first aid management and initial transfer Skeletal or skin traction in a Thomas splint can be used to provide both immediate and definitive management of thigh injuries (Figure 0320). It requires experience and several personnel to apply a Thomas splint quickly and effectively.

0935 Skeletal traction: • Under general, ketamine (0714) or local anaesthesia (0728), short medial and lateral incisions are made 1-2cm distal and 1-2cm posterior to the tibial tubercle (Figure 0913A). The muscles deep to the lateral wound are opened with forceps. Prior to inserting a pin, align the great toe and patella in the same vertical plain. A 4mm Steinman or Denham pin is inserted using a ‘T’ handle, there is no need to predrill the bone. • Stout cord is fixed under tension to both ends of the pin and hence to the end of the Thomas splint. Tightening is achieved using a windlass (Figure 0913B). • The pin site should be cleaned daily with saline and left exposed. Inspect for inflammation, tenderness and pin loosening. 170

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Fig 0913A Position for Steinman pin insertion through tibia.

0936 In skin traction, wide Elastoplast™ tape and a bandage are applied to the lower leg which is then fixed under tension by stout cord to the end of the splint (Figure 0914).

0937 Plaster on its own is unsuitable for femoral fractures. It can be used to support the leg in a Thomas splint by encasing both leg and splint in POP (Tobruk splint Figure 0915).

0938 External fixation is generally avoided when stabilising femoral fractures. When indicated, there must be sufficient proximal and distal bone to take three good pins into each segment, with at least 2-4 bars used to connect them. Insertion is through the anterior, lateral or postero-lateral surface of the femur. The safe area for pin insertion is shown in Figure 0916.

0939 At Role 4, intramedullary nailing may be carried out for definitive treatment. Alternatively, the casualty can be managed by Thomas splint and balanced traction (Figure 0917) until the fracture is healed.

0940 Decompression: The thigh contains three compartments: anterior (quadriceps), extensor (hamstrings) and medial adductor (Fig 0918). In civilian practice, release of anterior and posterior 171 chapter_9.qxd 28/09/2004 15:55 Page 172 9: Limb Injuries

Failure to decompress the deep posterior compartment is the commonest error when performing lower limb fasciotomy. This usually occurs when, in freeing up the soleus muscle, the surgeon mistakenly believes that he has released the compartment. Steinman pin

Windlass

Fig 0913B Skeletal traction in a Thomas splint. Tightening is by means of a windlass.

compartments through a single lateral incision, is usually sufficient. The superficial fascia is divided longitudinally over both compartments. Penetrating injuries to the thigh may require release of the medial 172 compartment through a separate incision. chapter_9.qxd 28/09/2004 15:55 Page 173 9: Limb Injuries

0914 Use of skin traction to immobilise a fractured femur in a Thomas splint.

Knee 0941 Injuries around the knee can be immobilised with a Thomas splint, or using a full-length POP backslab, with side supports at the knee and ankle. Extensive injuries can be effectively immobilised by external fixation with pins inserted in the femur (Figure 0916) and proximal tibia.

0942 The popliteal artery (0971) and peroneal nerve (0972) are at risk from posterior dislocation of the tibia.

Lower leg 0943 The prognosis for open fractures of the tibia is worse than that of other long bones. Consequently, 173 chapter_9.qxd 28/09/2004 15:55 Page 174 9: Limb Injuries

0915 Tobruk splint: the injured limb, Thomas splint and all attachments are encased in plaster.

they require appropriate, early wound excision, fasciotomy and immobilisation.

0944 Decompression: There are four compartments (Figure 0919): • Anterior. • Lateral. • Superficial posterior. • Deep posterior.

The posterior tibial artery is located between the two posterior compartments and is used as a landmark during surgery (Figure 0919). With the casualty in the 174 supine position, a two longitudinal incision technique

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Area into which pins should be inserted

Fig 0916 External fixation of the femur: safe area for insertion of pins. is recommended, leaving an adequate bridge of anterior skin (Figure 0919). To ensure complete decompression, incisions should extend from level with the head of the fibula to the malleoli.

0945 The anterior and lateral compartments are decompressed through a longitudinal skin incision between the lateral border of the tibia and the fibula (Figure 0920).

Fig 0917 Ballanced traction to treat a fractured femur. 175 chapter_9.qxd 28/09/2004 15:55 Page 176 9: Limb Injuries

Rectus femoris Vastus intermedius Vastus medIalis Femur Vastus Medial lateralis incision

Femoral artery and vein

Sartorius

Adductor Lateral longus incision Sciatic nerve Adductor Short head magnus of biceps

Gracilis Long head of biceps

Semimembranosus Semitendinosus

Fig 0918 Cross section of the mid thigh showing lateral and medial incisions used for decompression.

• The skin edges are undermined. The exposed fascia is first incised transversely to help identify the lateral intermuscular septum. • Separately incise the fascia over each compartment in the line of the skin incision. • Avoid the superficial peroneal nerve, which lies in the lateral compartment just posterior to the septum.

0946 The posterior compartments are decompressed through an incision 2cm posterior to the medial border of the tibia (Figure 0921). • The skin edges are undermined and the saphenous vein and nerve retracted anteriorly. • A transverse incision is made in the fascia in order to identify the septum between superficial and deep posterior compartments. 176 chapter_9.qxd 28/09/2004 15:55 Page 177 9: Limb Injuries

Anterior tibial Deep peroneal artery nerve

Anterolateral Posteromedial incision incision

Posterior tibial artery Superficial peroneal nerve Tibial nerve Peroneal artery Sural nerve

Fig 0919 Medial and lateral skin incisions and approach used to decompress the four lower leg compartments.

• The superficial posterior compartment, containing the gastrocnemius and soleus muscles, is decompressed by a longitudinal fasciotomy. • The deep posterior compartment is released by dividing the fascia overlying flexor digitorum longus and tibialis posterior muscles distally, then proximally under the soleus bridge. In order to adequately free the posterior compartment, the soleus may require mobilisation from the tibia.

0947 An above knee plaster backslab with side supports provides sufficient initial stabilisation for most fractures and soft tissue injuries Mould to the leg so that the ankle is held at 90 degrees and the knee is flexed to 30 degrees. A below knee POP is sufficient for ankle injuries (Figure 0903).

0948 External fixation is increasingly used (0918). Pins are inserted into the subcutaneous surface of 177 chapter_9.qxd 28/09/2004 15:55 Page 178 9: Limb Injuries

Anterior fasciotomy

Anterior intermuscular septum

Lateral fasciotomy

Fig 0920 Decompression of the anterior and lateral compartments: a short transverse incision is used to identify the anterior intermuscular septum. Separate fascial incisions are made over both compartments.

the bone (Figure 0905). Remember, the tibia is triangular in cross section: make sure there is There is no place for so-called 'blind' bi-cortical pin placement. fasciotomy via small skin incisions. 0949 Tibial traction is occasionally employed. A Steinman pin is inserted through the calcaneum, 2.5cm below the malleoli then, traction of approximately 0.5kg per 10kg body weight, is applied (Figure 0922). 178 chapter_9.qxd 28/09/2004 15:55 Page 179 9: Limb Injuries

Deep posterior fasciotomy

Superficial posterior fasciotomy

Intermuscular septum

Tibia

Saphenous nerve and vein

Fig 0921 Decompression of the superficial and deep posterior compartments. A short transverse incision is used to identify the intermuscular septum. Separate fascial incisions are made over both compartments. Retract the saphenous vein and nerve posteriorly.

Foot injuries 0950 Foot injuries are not life-threatening, but can cause late morbidity and impairment of function. Management principles are the same as listed above. Stabilisation of severe foot injuries can be difficult. Plaster is inadequate, except in the short term. External or wire fixation are preferred methods. The fracture can be stabilised by means of an external triangulation frame with pins inserted into the tibial shaft, the great toe metacarpal and a 179 chapter_9.qxd 28/09/2004 15:55 Page 180 9: Limb Injuries

Fig 0922 Calcaneal traction used to treat a fractured tibia.

transfixion pin through the calcaneus. By maintaining the foot at 90 degrees, the risk of developing an equinus deformity is reduced.

0951 At Role 4, management of severe foot injuries may include flap coverage, bone grafting, local bone fusion or partial amputations.

Civilian Limb Injuries 0952 Military limb trauma will predominate during armed conflict. On low-intensity military operations, civilian-type injuries are more common. Military surgeons require a basic knowledge of the emergency management of these injuries. Because most civilian fractures are closed injuries without the risk of wound contamination, there is less urgency for surgical intervention. The majority of these injuries can be simply managed by analgesia, splintage and transfer to a Role 3 facility or, local civilian hospital. Joint dislocations do require early reduction.

Upper limb

Clavicle fracture 0953 Fractures of the clavicle are common. They may be caused by direct trauma or indirectly e.g., falling on the outstretched hand. Most clavicle 180 fractures are closed, occur in the midshaft of the chapter_9.qxd 28/09/2004 15:55 Page 181 9: Limb Injuries

bone and are associated with overlap of the fragments. • Treatment is to rest in a broad arm sling (Figure 0317), followed by mobilisation as comfort allows. Internal fixation is occasionally performed.

Acromioclavicular joint injuries 0954 Disruption of the acromioclavicular joint is relatively common. It is typically a sports injury seen in young males. There is superior subluxation or dislocation of the lateral end of the clavicle; this is usually obvious on clinical examination. • Most injuries are treated conservatively with a broad arm sling (Figure 0317).

Fractures of the scapula 0955 Fractures of the scapula are uncommon injuries usually caused by direct trauma. Management of any associated chest injury takes priority. • Management is an arm sling with early active movement of the shoulder joint (Figure 0317).

Dislocation of the glenohumeral joint 0956 This is the commonest site of major joint dislocations in adults. In the majority, the humeral head is displaced anteriorly as a result of forced abduction/external rotation, often sport related. Less than 5% of dislocations are posterior. A dislocated glenohumeral joint should be reduced as early as possible; this can usually be accomplished under sedation. Ideally, a radiograph is obtained to confirm the diagnosis and exclude a fracture. If there is delay in obtaining a radiograph or, a history of previous dislocation, attempted relocation is justified. There are three common methods. Once relocated, the arm is rested in a sling. 181 chapter_9.qxd 28/09/2004 15:55 Page 182 9: Limb Injuries

Fig 0923 Hippocratic method for reduction of anterior dislocation of the shoulder joint.

0957 Hippocratic method: The casualty lies supine on a bed or the ground. Traction is applied Manoeuvres to to the arm with the elbow extended. The arm is then reduce a dislocation flexed and abducted at the shoulder. As traction of the glenohumeral joint should be continues to be applied, the humeral head is eased carried out gradually back into the joint, classically, by the surgeon's as spiral fractures stockinged foot (Figure 0923). of the humerus, and brachial plexus injuries have 0958 Kocher’s method: Traction is applied to the been reported. arm with the elbow flexed to 90 degrees.The arm is slowly externally rotated, then internally rotated and flexed across the body. Kocher’s method may be modified by abducting as well as externally rotating the arm (Figure 0924). A collar and cuff bandage in the axilla, can be used to provide counter-traction over the humeral head. Those who are not familiar with Kocher’s method, should use a different technique.

0959 Hanging-arm method: The advantage of this method is that it may be attempted by the inexperienced without sedation. The casualty is placed face down on a bed, or bent over a chair. The arm is allowed to hang free under gravity with the elbow extended; a fluid bag can be tied to the arm to provide traction.

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0960 Posterior dislocation: The humeral head appears ‘light bulb’ shaped on antero-posterior radiographs, an appearance that is best seen on a lateral or axillary view. Reduction is by applying traction to the abducted arm, followed by gentle external rotation.

Humeral shaft fracture 0961 Humeral shaft fractures commonly occur as a result of RTAs; there may be an associated radial nerve palsy causing wrist drop. Nerve exploration will be required. • Closed fractures are splinted with a plaster U-slab (Figure 0906). • Because of the risk of neurovascular damage, external fixation of this bone should only be attempted by an experienced surgeon (0925).

Elbow dislocation 0962 Axial loading on a slightly flexed elbow can cause it to dislocate posteriorly. There may be associated fractures of the distal humerus, radial head and coronoid. The elbow should be reduced as soon as possible; this is generally accomplished by closed means under GA. • Traction is applied with the arm slightly flexed. The olecranon can usually be pushed into place over the distal humerus, reducing with an audible ‘clunk’. • Post-operatively, the arm is immobilised in a collar and cuff.

Forearm fractures 0963 The majority of forearm fractures are displaced; definitive treatment is open reduction and internal fixation with plates. 183 chapter_9.qxd 28/09/2004 15:55 Page 184 9: Limb Injuries

.

Fig 0924 Kocher's manoeuvre for reduction of anterior dislocation of 184 the shoulder joint. 9: Limb Injuries 185 . Open (Figure 0925) In the field, the arm should be splinted until the In the field, the arm should casualty reaches a hospital. Use an above elbow POP splint with application of gentle traction to facilitate some reduction of the fracture. Ensure adequate immobilisation of the elbow. External fixation is inappropriate except for selected cases. fracture of one bone of this injury e.g., a Variants are uncommon; plus a dislocation of the other, they should not be diagnosed without an adequate radiograph. Position of backslab Fig 0925 fracture: application of a back slab. Wrist • • • • fractures Wrist 0964injuries and should be managed by a POP splint until The majority of wrist fractures are closed radiographs are available fractures are dealt with as in 0965. Hand injuries 0965 hands is common; damage to the Trauma chapter_9.qxd 28/09/2004 15:55 Page 185 Page 15:55 28/09/2004 chapter_9.qxd chapter_9.qxd 28/09/2004 15:55 Page 186 9: Limb Injuries

may include crushing and tendon lacerations. • Open wounds should be excised (0503), irrigated and the hand immobilised in a high sling (Figure 0317). Conserve as much tissue as possible. • Decompression may be necessary (0933). • In general, tendon (3027) or nerve repairs (2119) should not be attempted at a forward location. Transfer the casualty to a hand surgeon.

Lower limb Pelvic injury See 1315-1317 Hip dislocation 0966 This usually occurs during high energy vehicular trauma; There are two types.

Following hip • Ninety percent of dislocations are posterior. dislocation, exclude Clinically, the limb is shortened and internally associated injuries to the head, chest and rotated. Sciatic nerve palsy occurs in 10% of abdomen. cases (diagnosis 2115). There may be damage to the posterior acetabular wall (1308). • An anterior dislocation may cause femoral nerve palsy and rarely, damage to the femoral vessels. The limb is shortened and externally rotated. Beware - limb shortening and internal rotation 0967 Treatment is early relocation under GA occur with femoral (generally, this is not possible with sedation alone). neck fractures. In the dislocated position, the blood supply of the femoral head is compromised. Delay may cause osteonecrosis and permanent sciatic nerve damage. The casualty is placed on the floor or table. • In order to reduce a posterior dislocation, the pelvis is fixed by an assistant (Figure 0926). The operator takes control of the limb with the knee and hip each flexed at 90 degrees. Firm upward traction is applied. Slight adduction of the thigh may aid reduction. The femoral head 186 should palpably ‘clunk’ back into place. In

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Fig 0926 Reduction of a posterior dislocation of the hip.

extreme cases, the knee may be placed over the kneeling operator’s shoulder from behind as they face the casualty’s feet, allowing greater application of force.

• In anterior dislocations, the knee is flexed to 90 Approximately 5% of degrees and the hip to 60 degrees. The proximal all femoral shaft thigh is pulled laterally by an assistant: The thigh fractures will have an is adducted to 30 -40 degrees and the lower leg ipsilateral femoral neck fracture. rotated away from the body (internal rotation of the hip). Firm downward pressure on the kneecap causes the hip to relocate. • Following relocation of either type of injury, a distal femoral or proximal tibial traction pin (0935) is used to apply 10kg of skeletal traction for 6 weeks, followed by a further 6 weeks of partial or toe-touch weight bearing on crutches.

Femoral neck (hip) fractures

0968 A high energy injury is required to fracture The use of external the femoral neck in young casualties. If the fracture fixators on closed femoral shaft is displaced, there is a significant risk of avascular fractures is not osteonecrosis of the femoral head. Optimal care in recommended. young casualties is reduction and internal fixation within 6 hours. • Initial treatment in the field is to apply a traction splint or, other form of traction to the affected limb.

• For older casualties or when specialised 187 chapter_9.qxd 28/09/2004 15:55 Page 188 9: Limb Injuries

operative intervention is unavailable, bed rest in skeletal traction for 6 weeks may be the only alternative; the complication rate is high.

Femoral shaft fractures . 0969 If transfer to hospital is likely within two to three days, apply skin traction. Further management is described in 0939. If intramedullary nailing is unavailable within the theatre of operations, apply skeletal traction (trans-tibial or trans-femoral condylar Denham pin) for 6 weeks, followed by a hip spica or cast brace for 6 weeks.

Knee dislocation 0970 Dislocations of the knee are either anterior or posterior and are usually clinically obvious. If the cause was a vehicle accident, there may be a history of the kneecap striking the vehicle's dashboard.

0971 Between 20-35% of knee dislocations are associated with popliteal artery damage. An intimal flap tear is the most frequent finding (1005). This is important because the circulation may initially be intact. Later, as the flap extends, the circulation fails; this may be missed in a sedated casualty undergoing transfer. If appropriate, vascular repair is undertaken within 6 hours: even then, the amputation rate is 11%. Ideally, arteriography should be undertaken in all cases of knee dislocation (Figure 1004). Where arterial repair is delayed beyond 8 hours, the amputation rate is >85%.

0972 Peripheral nerve damage after knee dislocation occurs in 30-40% of casualties, particularly affecting the lateral peroneal nerve, leading to foot drop. Recovery may be limited and is not generally helped by nerve exploration. Excessive dimpling of the skin over the medial part of joint, combined with a knee that is irreducible, implies that 188

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the medial collateral ligament or joint capsule is entrapped within the joint. This requires surgery.

0973 Treatment is to relocate the knee as early as possible under GA. In the field, the limb is stabilised with a long leg POP back slab.(Figure 0903 B) Rapid assessment of the popliteal circulation by Doppler ultrasound or arteriography, is then undertaken. If neither is available and intimal damage is suspected, the artery is exposed and, if necessary repaired with a reversed saphenous vein graft (1030, 1048).

Patellar dislocation 0974 This is a separate entity from complete joint dislocation. The patella dislocates laterally after a low-energy blow to the medial side of the knee. The knee is held in flexion. • Simple extension of the knee allows spontaneous relocation. Vascular damage does not occur. • Subsequent treatment consists of 6 weeks in a padded POP cylinder with the knee in 5 degrees of flexion.

Tibial fractures 0975 Treatment: • Simple transverse or short oblique fractures (Figure 0901) can be managed to union in a POP cast for 8-12 weeks. • Open fractures are managed as in 0943. • Long, unstable spiral fractures, may benefit from the informed use of an external fixator to hold the bones in anatomical alignment (0948).

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Ankle dislocations 0976 Ankle dislocation typically occurs after falls or parachuting injuries. The deformity is obvious. Not infrequently, the skin is tented over the displaced talus and shows signs of vascular compromise. • Emergency reduction under analgesia is necessary. Longitudinal traction and correction of the deformity will allow the talus to relocate. • A well moulded, padded plaster is then applied. Check X-rays are taken to ensure adequate reduction. • Some dislocations will not reduce. This implies that a tendon, usually the tibialis posterior, has become displaced into the joint. This requires an open, medial approach, to free it and relocate the joint.

Ankle fractures 0977 Ankle injuries are common in all theatres of operations: • Isolated lateral malleolar fractures without any medial tenderness or injury, may be treated with ice, compressive elastic bandages, elevation and physiotherapy. • Where there is medial injury, either in the form of ligament damage or a medial malleolar fracture, a well-moulded below knee plaster is used as the definitive treatment (Figure 0903). • Most injuries involving service personnel are best managed by transfer to a Role 4 facility for internal fixation. • For local civilians in a Theatre of Operations, closed reduction and a below-knee POP, may be the only, or better, option to open reduction and internal fixation. 190 chapter_9.qxd 28/09/2004 15:55 Page 191 9: Limb Injuries

Ankle ligament sprains 0978 The majority of ankle sprains can be managed within the area of Operations and thereby avoid casualties unnecessarily clogging the transfer chain. • Treatment includes immediate physiotherapy, ice, compression, elevation, analgesia, support with stirrup taping or bracing and controlled mobilisation beginning 24 hours after injury. Avoid POP immobilisation.

Deep vein thrombosis (DVT) and pulmonary embolism (PE) 0979 Casualties suffering major limb, hip or pelvic trauma are at risk of developing a DVT and PE. Onset of symptoms is classically 3-7 after injury. Features of a DVT include: • Limb swelling. • Pain. • Redness. • Dilated superficial veins. • Calf tenderness. • Low-grade pyrexia. Up to 75% of DVTs are silent. Where thrombosis affects the veins above the knee, there may be embolisation to the lungs resulting in chest pain, dyspnoea and haemoptysis. Three percent of hospital deaths are due to PE. Confirmation of DVT is by venography or Duplex scanning (1016).

0980 The value of prophylaxis for these conditions in the field, is unclear. However, prophylaxis should generally be started as soon as haemorrhage is controlled.

• Traditional therapy is with s.c. heparin 5000 units 191

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12 hourly until ambulant. APTT monitoring is not required. • Prevention of dehydration, limb elevation, graduated compression hosiery and early mobilisation, may be of benefit. • Using a low molecular weight heparin is convenient (single daily dose) and will be more effective.

0981 Treatment of a confirmed case is by: • Continuous i.v. infusion of 25,000 -40,000 units of heparin per 24 hours. • Start oral warfarin. An initial regime is 9 mg of warfarin on Days 1 and 2 followed by 6mg on Days 3 and 4. Monitor by daily measurement of prothrombin time (PT). Once PT is twice or three times the control value, heparin can be stopped. Adjust the daily dose to keep PT in this range.

Fat embolism 0982 This complication typically occurs 3-10 days after major long bone fractures. Lipid globules lodging in the brain, lung, skin and kidneys may cause: • Drowsiness, confusion, coma and death. • Pyrexia and tachycardia. • Petechial rash over the upper trunk. • Dyspnoea, cyanosis and reduced PO2. • Renal failure. Diagnosis is confirmed by the finding of lipid globules in sputum or urine. The appearance of the lung on CXR is similar to that seen in ARDS. Treatment is supportive. Ventilation and dialysis may be necessary.

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Vascular injury

Introduction

1001 Major vascular injury in surviving The challenges of casualties is uncommon. Nevertheless, these vascular trauma are: injuries require timely intervention, with rapid • Making the control of haemorrhage at point of wounding or diagnosis. early recognition that bleeding is non-compressible. • Planning the This should be followed by urgent transfer to a appropriate surgical facility. It should not be forgotten that procedure. haemorrhage is the commonest cause of death • Exposing and controlling damaged on the battlefield - 10 to 20% of these deaths vessels. occurring in those with limb injuries. Casualties • Performing difficult with compressible haemorrhage are salvageable. surgery in adverse Those with non-compressible haemorrhage are likely circumstances. to die unless they undergo emergency surgery. Damage control techniques may be necessary (0407). The incidence of major vascular injury is between 1 and 4%, the vast majority involving the limbs. This figure has risen from 1% in WW II in parallel with the increasing use of pre-formed fragmentation weapons causing multiple wounds. Approximately 60% occur in the lower limb, 30% in the upper limb, 5% in the neck and the remaining few in the torso. Arterial injury alone is uncommon; 40% are associated with injury to a major vein and/or nerve. This is especially so in injuries around the axilla and popliteal fossa. Vascular injury is frequently accompanied by significant soft tissue damage and one third are associated with injury to bone.

193

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Mechanisms of combat vascular trauma 1002 These include:

Prior to definitive • Penetrating injury: low energy-transfer missile vascular repair, injuries and stabbings typically cause vessel fractures and laceration or transection. Occasionally, distal dislocations should flow is maintained by the surrounding be reduced and fixed. haematoma, leading to diagnostic difficulties. High energy-transfer missiles can result in massive vascular disruption. In these cases, injury can occur remote from the missile track due to stress wave and cavitation effects or, be caused by secondary bone fragments (0206). • Blunt trauma: vessel disruption can be direct (e.g., crushing) or indirect (e.g., traction or shearing). Examples of indirect trauma include damage to the brachial artery secondary to a supracondylar fracture of the humerus, or injury to the popliteal artery following dislocation of the knee joint. Blunt trauma, including the effects of blast, can result in intimal disruption and thrombosis.

Blood loss • Blast: see 0218. in trauma may be • Iatrogenic injury: examples include arterial into five sites: disruption during cannulation, accidental ligation • External. • Chest. or a neglected tourniquet. Occasionally, a major • Abdomen. vessel is deliberately tied off in an attempt to • Pelvis/ control life-threatening haemorrhage e.g., the retroperitoneum. internal iliac arteries after pelvic fracture (1282). • Around long bones (especially the femur). Consequences of vascular trauma

“Blood on the floor 1003 Haemorrhage: bleeding may be external and four more”. and obvious “blood on the floor”, or internal and hidden “and four more” - examine the four classical sites. Contained haemorrhage leads to haematoma formation. 194

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Fig 1001 Intimal flap and thrombus formation causing arterial obstruction.

1004 Ischaemia: may be acute, due to sudden If bleeding is completely controlled interruption of the arterial supply, or delayed. with direct pressure, Causes of delayed ischaemia include: development dressings or careful of a compartment syndrome (0906) and extension application of a clip of an intimal flap with slow build-up of thrombus. or tourniquet, this should be Irreversible tissue damage and necrosis rapidly maintained until the follow (brain: 3 minutes, muscle 6-8 hours). primary and secondary surveys 1005 Intimal flap and thrombosis: all forms are completed. of vascular trauma can cause part of the intima and media to become detached, leading to obstruction of the lumen. The distal circulation may initially be intact. The exposed thrombogenic surface can lead to thrombosis (Figure 1001). At operation, the outside of the artery often appears normal. The diagnosis is confirmed by pre-operative or on-table arteriography or, exploration.

1006 Arterial spasm: the ends of transected arteries tend to go into spasm and thrombose. Bleeding from lacerated vessels is more profuse because the partially intact wall prevents retraction. Arterial occlusion due to spasm alone is rare and should only be diagnosed after angiography or exploration, has excluded other causes.

1007 Arteriovenous fistula (AVF): an AVF occurs when an adjacent artery and vein are injured, 195 Chapter_10.qxd 28/09/2004 15:55 Page 196 10: Vascular injury

ARTERY

VEIN

Fig 1002 Arteriovenous fistula.

usually by penetrating trauma (e.g., radial artery and vein following a wound to the forearm). Arterial blood preferentially finds its way directly into the lower pressure venous circulation (Figure 1002). Most acquired AVFs present late, by which time the associated veins have become dilated and tortuous. Effects may include: a bruit, an increase in pulse rate, pulse pressure and cardiac output; distal ischaemia and, eventually, cardiac failure.

1008 False aneurysm: partial disruption of an arterial wall can lead to a walled-off, pulsating haematoma (Figure 1003). The contents of this false aneurysm remain in continuity with the lumen of the artery. Distal flow is often maintained making diagnosis difficult. Presentation is usually delayed.

196 Fig 1003 False aneurysm communicating with lumen of artery. Chapter_10.qxd 28/09/2004 15:55 Page 197 10: Vascular injury Management of Vascular Injury

Examination

1009 Assessment of circulation and haemorrhage NB: collateral control is performed during the 'C' part of the primary circulation may survey (0313). mean that pulses are occasionally 1010 Clinical assessment of acute limb ischaemia present at the ankle is undertaken during the secondary survey. Look for or wrist despite complete disruption the classical features (the six 'P's): of the brachial or • Pain. femoral artery. • Pallor. • Pulseless. • Paraesthesia. • Paralysis. • 'Perishing' with cold. The most important are paraesthesia and paralysis - nerves are very sensitive to anoxia. The absence of neurological signs implies no immediate risk of gangrene. Conversely, if they are present, circulation needs to be restored within 4 to 6 hours, assuming no pre-existing arterial disease. An expansile haematoma may be palpable. Examine for the presence of a palpable arterial thrill or audible bruit. Compare CRT in both limbs.

1011 Penetrating or blunt trauma to the common or internal carotid arteries can cause cerebral ischaemia. Neurological signs, especially in the young, are sometimes subtle. Early investigation by Duplex scanning or arteriography may be necessary.

197

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Fig 1004 On-table arteriogram. Position X-ray plate under sterile drapes. Place opaque marker adjacent to site of injury. Inject contrast via proximal needle and syringe.

Investigation

Role 1 & 2

The presence 1012 Pulse oximetry: a digital probe is a of palpable distal simple method of monitoring extremity tissue oxygen pulses, a normal saturation; always compare with the uninjured limb. CRT or a Doppler signal do not NB: saturation is affected by the haemoglobin absolutely exclude concentration. vascular injury. 1013 Doppler: a hand-held Doppler probe may be available to detect blood flow at the ankle or wrist. Apply conducting jelly, position the probe at 45 degrees to the direction of flow and listen for the characteristic 'whoosh'.

1014 Ankle brachial pressure index (ABPI): using the Doppler probe and a sphygnomanometer, measure the systolic pressure over either the posterior tibial or dorsalis pedis arteries and the casualty's brachial artery. Dividing the ankle pressure by the brachial pressure should give an ABPI of > I.0. A value of 0.7 or less indicates significant ischaemia. Serial measurements of the ABPI may be useful for detecting deterioration in blood supply.

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1015 On-table arteriography; this relatively Arteriography is an unnecessary and simple investigation should be available at most time wasting Role 2+ or 3 facilities to confirm arterial damage pre-operative and demonstrate its location. In the operating theatre procedure when the an X-ray plate is placed under the drapes opposite diagnosis is obvious! the site of trauma (Figure 1004). Between 20 and 50mls of radio-opaque contrast is rapidly injected into the exposed artery proximal to the injury. Approximately 10 seconds later the plate is exposed (allow a one second delay for each centimetre of travel).

Role 3 & 4 1016 Doppler ultrasound (Duplex): this is a combination of Doppler and b-mode continuous wave ultrasound. It is quick, non-invasive and has, in certain areas, replaced arteriography. Duplex scanning can detect arterial and venous disruption or occlusion, intimal flaps, haematomas, false aneurysms and arteriovenous fistulae.

1017 Digital subtraction angiography (DSA). This will only be available at a Role 4 facility.

1018 Computerised tomography (CT): The CT scanner is contrast-enhanced CT scanning can be used to a dangerous place diagnose vascular injury in the neck, chest and for an unstable casualty; access abdomen. In civilian practice, early whole-body CT is restricted and scanning, is favoured by many for the assessment sudden deterioration of casualties with multiple trauma. may go unnoticed.

Immediate treatment 1019 This may summarised as follows: • Compressible haemorrhage is controlled by a combination of direct pressure, elevation, splinting or a tourniquet (0330). Fibrin-impregnated field dressings and other topically applied adjuncts for haemorrhage control are available. 199 Chapter_10.qxd 28/09/2004 15:55 Page 200 10: Vascular injury

a) b)

Fig 1005 a) Embolectomy/thrombectomy using a balloon catheter. b) Installation of heparinised saline.

• Casualties with non-compressible haemorrhage require hypotensive resuscitation (0333) and urgent transfer to a surgeon for operative control. Occasionally, a resuscitative laparotomy and/or thoracotomy are necessary as part of the primary survey. • Where facilities are available and the casualty remains stable, consider interventional radiology to control haemorrhage.

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Simple vascular repair

Artery 1020 Exposure and control: expose the artery If bleeding proximal and distal to the injury. Control small continues, look for missed injury to vessels by passing a silastic sling or fine ligature collateral vessels. twice around the vessel and apply gentle traction. Ideally, larger vessels require application of vascular clamps. Reduce intimal damage by closing the clamp's ratchet just enough to achieve occlusion. Vessels can also be controlled by 'snugging-down' encircling slings. In difficult circumstances, consider inserting proximal and distal intraluminal balloon catheters; they are less traumatic than a vascular clamp hurriedly misapplied.

1021 Inadequate back bleeding and inflow: Standard vascular this is probably due to thrombus formation and can techniques are: be cleared by the passage of a balloon catheter up • Non-crushing and down the lumen (Figure 1005): clamps. • Fine Prolene • Choose an appropriate size e.g., size 5 sutures. Fogarty above and size 3 below, the • Balloon common femoral artery. thrombectomy. • Remove the stylet. Check the balloon by inflating • Spatulation for small anastomoses. it with a syringe containing the recommended • Completion volume of saline. angiogram. • Gently pass the catheter into the artery, ensuring it lies within the lumen. Ideally, prior angiography will have excluded an intimal tear; this can be worsened by blind instrumentation. The distance travelled is indicated by marks on the outside of the catheter. • Inflate and vary the pressure using the syringe, so that the balloon just makes contact with the arterial wall during its slow withdrawal. Continue 201 Chapter_10.qxd 28/09/2004 15:55 Page 202 10: Vascular injury

Fig 1006 Fixing an intimal flap.

passing the balloon until no further thrombus is extracted. • Flush the proximal and distal lumen with several syringes of heparinised saline (5,000iu heparin per 500ml saline).

Where simple repair 1022 Intimal flap: inspect the lumen of the significantly narrows artery for intimal flaps. Anchor these down using the lumen i.e., >25% a double-ended 5/0 Prolene suture. Pass each perform a patch angioplasty. If in needle through the flap from inside to outside the doubt patch it. vessel (Figure 1006). Tie on the outside. Defects on the back wall require rotation of the artery.

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a)

2 mm b)

2 mm

Fig 1008 Simple arterial repair of a major vessel: a) use two double ended Prolene sutures. b) Place sutures 2 mm from edge and 2 mm apart.

1023 Repair: trim the edges of a ragged laceration taking minimal tissue (Figure 1007). Effect closure with a lateral repair providing this does narrow the lumen. Use a double-ended Prolene suture: • 3/0 for the aorta. • 4/0 for the iliac arteries. • 5/0 for the femoral arteries. Pass each needle from inside to out at the comer of the arterial wound (Figure 1008). Repeat with a second suture at the other end of the wound. Tie and attach a clip to the shorter end to use as a stay suture. Using the longer end, suture in the direction of flow using a simple over-and-over technique. Take care to pick up all layers of the vessel wall. Each bite should be 2mm apart and a similar distance from the wound edge. Handle the artery gently. To prevent intimal damage, avoid grasping the full thickness of the vessel with forceps. Insert 2-3 bites using the long end of the distal suture working proximally.

1024 Restoration of flow: before completing the anastomosis, ensure that back bleeding and inflow are satisfactory (1021). Carefully release the distal 203

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clamp, sling or balloon, instil heparinised saline and re-occlude to prevent embolus passing distally when proximal control is released. Then release proximal control to assess forward flow. Complete the vascular repair. Before tying the final suture, temporarily release the proximal occlusion to flush out any clot or debris. Balloon catheters are deflated and removed at this stage. Leave the suture ends long to prevent unravelling.

1025 Anastomotic bleeding: this can normally be controlled by gentle pressure without occluding the vessel. If there is a major coagulopathy, The anastomosis can easily be ruined transfusion of clotting factors may be necessary. by a poorly-placed Use 'rescue' sutures sparingly. They should be suture which narrows placed parallel to the line of the anastomosis, the lumen. taking a small bite through the adventitia of the artery (or vein patch) on either side of the leak. Tie with tension just sufficient to control haemorrhage.

1026 Completion angiography: following repair of a small-calibre vessel, perform an angiogram to ensure a satisfactory run-off (1015). Bleeding from the puncture site can be controlled with direct pressure or the placement of a small adventitial 'Z'-stitch.

1027 Fasciotomy: consider whether the limb is at risk of developing a compartment syndrome (0906). A fasciotomy is often beneficial following vascular repair (0908).

1028 Drainage and cover: use closed suction drainage for all limb vascular repairs unless they lie within the primary wound. Drains should be removed when they cease to drain. If a repair is sited within a primary wound which is to be left open for subsequent delayed closure, do not apply dressings directly to the repaired vessel. (0503), it is likely to thrombose or rupture. Cover the repair by swinging 204 across a local muscle flap:

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• Sartorius and gastrocnemius in the thigh and lower leg. • The scalene muscles or trapezius for the carotids. • Latissimus dorsi for the axillary vessels. Failing this, tack together viable local soft tissues over the involved vessels. Then apply dressings. Obtaining cover for large wounds may necessitate the use of relieving skin incisions or local fascio-cutaneous flaps: seek the advice of a plastic surgeon.

Vein 1029 With concomitant injuries to major veins and arteries repair the vein first. This will reduce troublesome venous bleeding during arterial repair. If other injuries in the limb require attention e.g., external fixation of a fracture, consider placing temporary shunts in both the vein and artery (0411). Venous bleeding is initially managed by applying pressure either side of the defect, e.g., using swabs on sticks. This is safer than trying to dissect out, sling and clamp the vessel. Small vessels may be ligated. Large veins should, when feasible, be repaired with 5/0 Prolene sutures (1030), especially if there is extensive soft tissue injury that may have compromised other venous channels. Complex grafts, for example spiral and panel grafts, constructed to bridge defects in large veins, are technically demanding and time-consuming in practise. Nevertheless, every effort should be made to restore continuity of large veins, even if only temporarily. This may involve the use of PTFE grafts in selected cases. Ligation of the vein should be the last resort.

Advanced vascular repair The following require time, technical skill and judgement. They are best performed on stabilised casualties. 205

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a)

b)

c)

Fig 1009 a) Excise the damaged arterial segment at an angle. b) Place two stay sutures. c) Technique of end-to-end anastomosis. Use the stay sutures to rotate the artery.

End-to-end anastomosis 1030 This technique is suitable for arterial and venous repairs where the vessel ends can be approximated without tension.

• Check that the inflow and backflow are satisfactory (1021). Mobilise and control the vessel above and below the defect (1020), (Figure 1009 a) 206 Chapter_10.qxd 28/09/2004 15:55 Page 207 10: Vascular injury

• Divide the ends at an angle to reduce anastomotic stenosis (Figure 1009 b). Insert two stay sutures. Alternatively, insert and tie a double-ended Prolene (1023). • Suture between the stays using a continuous suture for vessels >6mm diameter (e.g., common femoral artery) or, interrupted for smaller vessels. Pass the needle from outside-in proximally and inside-out distally. Use the stays to rotate the vessel, (Figure 1009 c). • Restoration of flow - see 1024.

Interposition graft

1031 An interposition graft is used to bridge a damaged vessel where the ends cannot be approximated without tension. • The best graft material is autologous vein, the Where there is long saphenous vein (LSV) is ideal. Vein is the doubt about preferred material if the graft crosses a joint. excessive tension The LSV is usually harvested from the groin of it is wiser to insert an uninjured leg. The calibre of the vein at this an interposition graft. site is sufficient to replace vessels up to the diameter of the superficial femoral artery. • Tributaries of the LSV are ligated using fine, non-absorbable ties. To prevent the valves interfering with flow, the vein must be reversed. Mark one end of the vein to avoid confusion! Irrigate with heparinised saline. • Divide the ends at an angle to reduce narrowing and insert stay sutures (Figure 1010). Perform an end-to-end anastomosis as in 1030. If the graft is being inserted end-to-side, vein to artery, suture the heel of the vein first using a 'parachute' technique. Cut the graft to the required length after completing the first anastomosis. 207

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x

x

a)

b)

c)

Fig 1010 Reconstruction using an interposition graft: a) If the graft is narrower, incise as shown. b) Place stay sutures. c) After completing the first anastomosis, trim to length. Use the stay sutures to rotate the artery.

• If suitable vein is not available or a shortened operating time essential, consider using a synthetic graft, PTFE is preferred. It is no longer anathema to use synthetic grafts in war wounds, providing the graft is covered (1028), suitable antibiotics are administered and the casualty can be observed for secondary haemorrhage. Even if the graft becomes infected or occluded, subsequent extra-anatomical by-pass with excision of the first graft, may save the limb.

208

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Fig 1011 Patch angioplasty.

Patch angioplasty 1032 This is the preferred method of closing lacerations affecting small vessels (<6mm) so as to prevent stenosis. • Usually there will be a suitable segment of vein available at the site of injury, if not, harvest part of the proximal long saphenous vein. • Control the vessel and trim the jagged edge of the defect. • Cut the vein patch to the required size and round the ends in order to reduce apical narrowing. • Fix in place using a double-ended Prolene suture. The apical sutures should be laid in such a way as to resemble the outspread fingers; this prevents narrowing of the lumen. Aim to tie the Prolene along one side of the patch, not at the apex, (Figure 1011).

209

Restoration of flow: see 1024. a) Axillo-femoral. b) Femoro-femoral crossover. an end-to-side anastomosis - of performing Technique c) first place sutures in the 'heal' and parachute down before working round the 'toe'. c) a) b) Fig 1012 Extra-anatomical bypass grafts:

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Bypass procedures 1033 Extra-anatomical bypass procedures are occasionally required but, rarely indicated in the field, even if feasible. Indications include: • Following ligation/obstruction of major arteries. • Where there is wound contamination. • Because of extensive soft tissue loss. Examples are: an axillo-femoral graft or a femoro-femoral crossover (Figure 1012). A synthetic graft is anastomosed end to side to the respective arteries after being tunnelled subcutaneously between them. This can be performed under LA in the high risk casualty.

Repair of arteriovenous fistulae 1034 The artery and vein should be controlled proximally and distally and the fistula disconnected. Each defect is repaired with Prolene. Interposition of a muscle pedicle will reduce recurrence.

Post-operative management 1035 This includes:

• Monitor pulse, BP, respiratory rate, temperature Deteriorating limb and urine output. circulation may be an indication for • Elevate the limb and keep the digits exposed. angiography, radiological • Observe the six 'P's and CRT (1010). intervention, Assessing circulation with pulse oximetry (1012) re-exploration and Doppler (1013), may give an early clue or amputation. to deterioration. • Consider the need for DVT/PE prophylaxis (0980) • Drains can usually be removed at 48 hours. • Regular wound examination is harmful unless there is an indication to do so (0508). A serous or lymphatic leak generally resolves spontaneously. 211

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Fig 1013 Incision along anterior border of sternomastoid muscle.

• Sutures can usually be removed at 7-10 days.

Vascular Exposure

Following vascular trauma, rapid and adequate access to involved vessels is essential.

Vessels at the root of the neck 1036 Damage to the subclavian, carotid and vertebral arteries is usually caused by penetrating trauma and can lead to massive haemorrhage into the neck and chest. The common carotid artery is more likely to be affected than its branches, as the bifurcation is high in the neck and protected by the angle of the jaw. Avulsion injuries generally occur at the origin of the main arteries on the arch of the aorta.

Carotid, brachiocephalic and proximal subclavian vessels 1037 Injuries below the cricoid cartilage: • Approach is via a median sternotomy incision (1538). This gives good access to the proximal left common carotid artery (LCCA), brachiocephalic artery (BCA), proximal right subclavian artery (RSA) and origin of the right common carotid artery (RCCA). The LCCA and 212 BCA are initially intrapericardial. Chapter_10.qxd 28/09/2004 15:55 Page 213 10: Vascular injury

Internal carotid artery Common facial vein External carotid artery

Internal jugular vein

Middle thyroid vein

Omohyoid muscle

Fig 1014 Exposing the carotid sheath.

• Median sternotomy is often combined with an extension into the neck along the medial border of the sternomastoid muscle (Figure 1013). • It may be possible to obtain sufficient exposure of the proximal left subclavian artery (LSA) via a median sternotomy; other options are: a left anterior thoracotomy (1534) or trapdoor incision (1540).

1038 Injuries above the cricoid cartilage:

• Approach via a longitudinal incision along the Have an arterial anterior border of the sternomastoid (Figure 1013) clamp to hand in from 2cm below the mandible to the suprasternal the event of major haemorrhage. notch. Turn the head to the opposite side and support with the neck slightly extended. • Divide the platysma and the deep fascia in the line of the skin incision. Retract the muscle laterally to reveal the carotid sheath. Incise and dissect along the anterior border of the internal jugular vein (IJV) to expose the common carotid artery (CCA) (Figure 1014). Tributaries of the IJV (e.g., common facial vein, middle thyroid vein) and the omohyoid muscle, usually require division. 213

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Diagastric muscle Accessory nerve Glosso-pharyngeal nerve

Superior laryngeal nerve

Hypoglossal nerve

Vagus nerve Ansa hypoglossi Retracted internal jugular vein

Common carotid artery

Fig 1015 Common carotid artery, internal and external carotid arteries and associated nerves.

• Retract the IJV laterally. Pass a sling around the CCA. Avoid the vagus nerve which lies behind and the ansa hypoglossi and hypoglossal nerve, which lie in front of the artery (Figure 1015). Continue the dissection cephelad. • If required, access can be improved by division of the posterior belly of the digastric muscle and the sternomastoid muscle near its insertion. NB: avoid the glossopharangeal and accessory nerves. • Above the carotid bulb, pass slings around the internal (ICA) and external carotid arteries (ECA). The ECA lies anterior to the ICA and gives off branches in the neck; it can be safely ligated. • Because of the risk of stroke, the CCA and ICA should be repaired. Allow free back bleeding to avoid embolisation of air, thombus or debris before releasing the proximal clamp. Occlusion for more than four minutes requires insertion of a temporary shunt (0411). 214 Chapter_10.qxd 28/09/2004 15:55 Page 215 10: Vascular injury

Fig 1016 Incision used to expose the distal subclavian artery.

Vertebral arteries

1039 Injuries to the origin of the vertebral artery Casualties with are accessible via an incision along the anterior penetrating injuries border of sternomastoid (Figure 1013). The of the cervical sternomastoid is divided and swung laterally. spine have a 95% mortality. The carotid artery and the jugular vein are mobilised and retracted medially to reveal the vertebral artery. Once the artery has entered the bony canal, bleeding can only be stopped with difficulty and attempts are likely to be futile.

Upper limb

Distal subclavian artery 1040 Exposure is via a supraclavicular approach. This can be difficult to perform quickly. Consider Upper limb vessels temporary control by pressure applied to an inflated are more delicate balloon catheter inserted through the wound (0330). than lower limb and require • Make a horizontal incision 1cm above the careful handling. medial two-thirds of the clavicle and divide the fat and platysma (Figure 1016). Access can be improved by excising the clavicle medial to the coraco clavicular ligament (Figure 1017). • Ligate and divide the external jugular vein. • Mobilise the scalene fat pad to expose the scalenus anterior muscle. Identify and preserve 215

Classiffication of Neck Injury According to Zones: see 1924 Chapter_10.qxd 28/09/2004 15:55 Page 216 10: Vascular injury

Retracted pectoralis major muscle Retracted trapezius muscle

Branches of brachial plexus

Subclavian artery Scalenus anterior muscle Phrenic nerve

Subclavican vein Divided clavicle

Fig 1017 Exposure of the distal subclavian artery can be improved by excising the middle third of the clavicle. Divide scalenus anterior close to its insertion into the first rib (NB: preserve the phrenic nerve).

the phrenic nerve as it crosses the muscle from lateral above to medial below. Beware the cords of the brachial plexus. Divide scalenus anterior near its insertion on the first rib, this will expose the subclavian artery.

Axillary artery 1041 The axillary artery commences opposite the lateral border of the first rib and becomes the brachial artery at the lateral edge of teres major. It is divided into three parts, the mid portion lying behind pectoralis minor (Figure 1018).

Clavicle

Incision

Coracoid process

Pectoralis minor

Pectoralis major

Axillary artery

Fig 1018 Approach to the axillary artery. Separate or divide fibres of pectoralis major. Divide pectoralis minor which overlies the second part 216 of the artery. Chapter_10.qxd 28/09/2004 15:55 Page 217 10: Vascular injury

Fig 1019 Exposure of the axillary artery (NB: avoid damage to the brachial plexus and pectoral nerves).

• Make an incision 2cm below the lateral half of the clavicle extending onto the upper arm (Figure 1018). Split the fibres of pectoralis major and insert a self-retaining retractor. For greater exposure divide the clavicular and humeral heads of pectoralis major (Figure 1019). Preserve the medial and lateral pectoral nerves. • Pass a finger around pectoralis minor and divide the muscle near its insertion into the coracoid process of the scapula (1018). • Dissect the axillary artery away from the axillary vein and control with slings.

Brachial artery 1042 The brachial artery passes down the medial aspect of the arm beneath the deep fascia. It is crossed by the median nerve, which comes to lie medially in the antecubital fossa (Figure 1020). Here the artery divides into radial and ulnar branches. • Abduct the arm. Make a longitudinal incision along the medial border of biceps. • Divide the deep fascia and dissect the artery from the nerve.

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Biceps

Median nerve Site for incision

Brachial artery Pectoralis minor

Ulnar nerve

Triceps

Fig 1020 Relations/approach to the brachial artery

Radial and ulnar arteries 1043 The origin of both arteries lies superficially in the antecubital fossa. Exposure and repair is rarely necessary. As long as one of the arteries remains patent, the other can be ligated. • Place the arm abducted on a board with the palm facing upwards. • To expose the radial artery make a longitudinal incision along the antero-lateral aspect of the forearm (Figure 1021). Divide the deep fascia

Radial artery

Ulnar artery

Fig 1021 Incisions used to expose the radial and ulnar arteries. 218

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Radial artery

Brachioradialis muscle

Median nerve Flexor carpi ulnaris muscles Superficial flexor Ulnar nerve muscles Ulnar artery and nerve Brachial artery Median nerve

Fig 1022 Relations of the radial and ulnar arteries

and dissect in the interval between brachioradialis and the long flexors muscles (Figure 1022). • To expose the ulnar artery, make a longitudinal incision along the antero-medial aspect of the forearm (Figure 1021). Dissect between the long flexor muscles and flexor carpi ulnaris (Figure 1022).

Lower limb

Common iliac (CIA) and internal iliac arteries (IIA) 1044 Following penetrating trauma, the iliac arteries are approached via a standard midline laparotomy incision (1282).

External iliac artery (EIA) 1045 In casualties with a groin injury, it may be necessary to expose the EIA in order to obtain proximal control. Extend the vertical groin incision upwards and laterally (Figure 1023). Divide the inguinal ligament and abdominal wall muscles in 219

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Inverted hockey stick incision Incision for exposure of femoral artery

Fig 1023 Inverted hockey stick approach to external iliac artery. Approach to femoral vessels in the groin.

the line of the incision passing lateral to the deep inguinal ring. Push the peritoneum forwards off the iliac vessels. Avoid entering the abdominal cavity. For large wounds in the femoral triangle, obtain rapid proximal control by clamping the aorta. Do not waste time delving blindly into the wound.

Femoral artery and vein 1046 Femoral arteries • Make a vertical incision over the femoral artery Treat arteries starting just below the mid point of the inguinal with respect. Rough ligament (Figure 1023). Continue for 10-15cm, handling can lead to or until sufficiently distal to the injury. intimal damage and tear the adjacent • Incise through fat and fascia and develop a vein. Pass each rubber sling twice plane along the length of the artery (Figure around iliac or 1024). Pass slings around the common femoral femoral arteries from (CFA) and superficial femoral arteries (SFA). the medial side using Control side branches using heavy, untied curved forceps. ligatures passed twice around the vessel. • At a variable distance in the wound, the CFA divides into the SFA and profunda femoris arteries (PFA). The CFA may be seen to narrow at this point. Traction on the proximal and distal slings will reveal the deeper-lying PFA, usually 220 on the lateral side of the SFA. Pass a sling

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Inguinal ligament

Common femoral artery Long saphenous vein Common femoral vein

Profunda femoris artery

Superficial femoral artery Superficial femoral vein

Fig 1024 Exposure of the femoral vessels in the left groin.

around the PFA taking care to avoid the profunda femoris vein (PFV). • Where necessary, the SFA can easily be followed distally; there are no branches of significance in the thigh. Tracing the PFA is more difficult; it has multiple side branches which must be controlled using heavy ties.

1047 Femoral veins

The need for venous repair is discussed in 1029. Where possible, preserve the long • The common femoral (CFV) and superficial saphenous vein femoral veins (SFV) lie medial to their respective which may be arteries; together with the PFV, they are required for a subsequent controlled with slings. reconstruction. • The long saphenous vein lies in the subcutaneous tissues of the medial thigh. It passes through a window in the deep fascia to join the CFV in the groin. The LSV may require ligation or control with a sling. 221 Chapter_10.qxd 28/09/2004 15:55 Page 222 10: Vascular injury

Fig 1025 Approach to the popliteal artery. Popliteal vessels 1048 The popliteal artery extends a hand's breadth above and below the line of the knee joint. Depending on the site of injury, the artery is usually exposed via a medial incision above the knee which can be extended distally as necessary. If there is extensive bleeding, it is safer to obtain proximal control in healthy tissue prior to opening the haematoma. • Position the leg as in Figure 1025. • The above knee popliteal artery is first exposed via a 15cm long incision placed 2cm behind the posterior border of the distal femur on its medial aspect.

Medial head of gastrocnemius Adductor magnus Popliteal artery and vein emerging from adductor canal Sartorius

Saphenous nerve

222 Fig 1026 Exposure of the popliteal vessels above the knee. Chapter_10.qxd 28/09/2004 15:55 Page 223 10: Vascular injury

Adductor magnus

Divided sartorius Popliteal artery and vein Medial head of gastrocnemius

Divided common insertion of sartorius, gracilis and semitendinosus

Anterior tibial artery and vein

Posterior tibial artery and vein

Soleus muscle

Fig 1027 Exposure to the popliteal vessels below the knee.

• The subcutaneous fat and deep fascia are incised and the dissection continued deep to the anterior border of sartorius (Figure 1026). Sweep aside the popliteal fat pad to expose the artery. It is usually surrounded by two venae commitantes. Control with slings and occlude side branches with heavy ties. • Expose the below knee popliteal artery as necessary (Figure 1025). To improve access it may be necessary to divide the tendons of sartorius, gracilis, semimembranosus and semitendinosus along with the medial head of gastrocnemius (Figure 1027). The artery and its accompanying venae commitantes will be found lying close to the posterior surface of the tibia. The tibial nerve lies posteriorly. Control the artery with slings. • If there is an isolated popliteal artery injury between the femoral condyles, a posterior approach using a lazy-S incision, should be considered. This avoids dividing the muscles and tendons on the medial aspect of the knee.

223

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Anterior approach

Medial approach

Lateral approach

Fig 1028 Approaches to the crural vessels.

Crural vessels 1049 The main branches of the infrageniculate popliteal artery are the anterior tibial, posterior tibial and peroneal arteries. Because only one of these is required to maintain foot viability, repair is rarely necessary.

1050 Anterior tibial artery The artery arises from the lateral border of the popliteal artery near the soleal arch. It may be exposed via a 15cm longitudinal incision just anterior to the tibia (Figure 1028). Divide the fascia and dissect in the plane between tibialis anterior medially and extensor digitorum longus and extensor hallucis longus laterally (Figure 1029). The anterior tibial artery and veins lies deep to these muscles on the interosseous membrane.

1051 Posterior tibial artery Expose via a 20cm longitudinal incision down the medial side of the leg, just behind the posterior border of the tibia (Figure 1028). Incise the deep fascia and separate the soleus from its attachment to the tibia (Figure 1030). In the proximal calf, the 224 Chapter_10.qxd 28/09/2004 15:55 Page 225 10: Vascular injury

Deep peroneal nerve

Tibialis anterior muscle

Anterior tibial Extensor digitorum artery and vein longus muscle Extensor hallucis longus muscle

Fig 1029 Exposure of the anterior tibial artery.

posterior tibial artery lies deep to soleus on flexor digitorum longus. Exposure of the artery is easier in the distal half of the calf where it lies more superficial.

1052 Peroneal artery The artery can either be exposed by a deepening of the incision used to expose the posterior tibial artery (Figure 1028), or via a longitudinal incision directly over the fibula. In the latter, muscle attachments are stripped off the fibula and a segment excised using a Gigli saw (Figure 1031). The peroneal artery lies immediately deep to the fibula.

Retracted flexor digitorum Peroneal longus artery and vein Retracted Posterior tibial gastrocnemius artery and vein and soleus muscles

Fig 1030 Exposure of the posterior tibial artery. 225 Divided fibula Peroneal artery and vein Fig 1031 Exposure of the peroneal artery.

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Amputation

Introduction

Surgical amputation 1101 Traumatic amputation is one of the most is a form of radical devastating consequences of armed conflict and is wound excision. frequently due to blast or antipersonnel mine injury Inadequate initial (Figure 1101). Unless the blast is focused, death is treatment can result in gas gangrene, the usual outcome. Victims of antipersonnel mines increased morbidity generally survive despite a significant amputation or death. rate. In modern conflict surgery, traumatic lower limb amputation account for 5-10% of all injuries, with non-combatants and children frequently affected. The wounds are usually complex, with multilevel injury to skin, muscle, neurovascular structures and bone. Re-implantation is not possible.

It is better to lose 1102 In a military setting, an unsalvageable a limb than the life limb is usually obvious and the decision to operate of the casualty. straightforward: the surgeon simply completes the amputation. Management of lesser wounds can be difficult, especially when dealing with bilateral limb injuries or severe crush injury. Where possible, obtain a second opinion. Perform wound excision, fasciotomy and lavage. Take a photograph and observe the limb for 24-48 hour. During high intensity warfare with limited facilities, mass casualties and transfer delays, amputation may be indicated for injuries that might be salvageable in a civilian environment.

General Principles

1103 Amputation is disabling, distressing and irreversible. Despite the emotive nature of the injury, 227

Fasciotomy: see Chapter 9 Fig 1101 limb. of a mine blast on the lower Effect

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particularly when dealing with children, initial management priority remains ABC. Unless there is major haemorrhage, management of the limb wound is not addressed until the casualty has been resuscitated.

1104 In the military environment, accepted If the wound remains contaminated or still practice is an emergency amputation, preserving as contains necrotic much viable skin, soft tissue and bone as possible. tissue when Because of the degree of likely contamination, a examined at 48 second-look wound excision is undertaken 48 hours hours, further excision is required later. If clean, a delayed primary closure of the and closure delayed wound is performed within 3-5 days, ideally for subsequent employing a myoplastic repair. By then, the casualty wound inspection. should be at a Role 3 or 4 facility. After the wound

has healed, definitive amputation may still be Delayed primary required weeks or months later. closure should be performed 1105 Administer antibiotics (0816) and tetanus before skin and muscle retract toxoid (0825). and become fixed.

Emergency Amputations

1106 Indications Arterial injury: amputation is performed if there is limb ischaemia ('6 P's' 1010) with significant soft tissue damage. If the injury is mainly arterial, with only moderate distal soft-tissue damage and minimal delay in revascularisation, consider vascular repair or insertion of a temporary arterial shunt (1023, 0411). Severity of damage (mangled limb): In the lower Amputation is usually limb, amputation is indicated for significant skin, indicated because of soft tissue, nerve or bone defects, especially in soft tissue rather combination. Various scoring systems have been than skeletal devised to aid decision-making including the damage. Loss of bone without nerve 'Mangled Extremity Severity Score’ and vascular injury (MESS - Table 1101) Amputation (in the absence may not justify of life-threatening damage) is justified in the upper amputation. 229

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limb only if the magnitude of injury precludes recovery of any degree of function in the hand, fingers or thumb. Overwhelming infection: delays in treatment commonly result in grossly infected wounds and septicaemia. In gas gangrene (0829), it is important to amputate one level higher than the superficial tissue changes would suggest i.e., if infection is confined to the lower leg, perform an above knee amputation. In necrotizing fasciitis, it is usually sufficient to excise the affected muscle compartment (0832). Rapid amputation may be the only Entrapment: In casualties trapped for >6 hours with way to resuscitate a pulseless leg, release can cause fatal cardiac the casualty. arrest due to K+ ion and lactic acid release (0921).

Skeletal/soft-tissue injury Low energy (stab, simple fracture, pistol gunshot wound) 1 Medium energy (open or multiple fractures, dislocation) 2 High energy (high speed RTA or rifle GSW) 3 Very high energy (high speed trauma + gross contamination) 4

Limb ischaemia* Pulse reduced or absent, but perfusion normal 1 Pulseless; paraesthesia, diminished capillary refill 2 Cool, paralysed, insensitive, numb 3

Shock Systolic BP always >90mmHg 0 Transient hypotension 1 Persistent hypotension 2

Age (years) <30 0 30-50 1 >50 2

If score above 7 - Amputate. If score below 6 - Try to save.

* If the warm ischaemia time is over 6 hours, this score is doubled.

230 Table 1101 Mangled Extremity Severity Score (MESS).

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Above knee

Through knee disarticulation

Below knee

Syme

Transmetatarsal

Fig 1102 Levels of lower limb amputation. This also applies to casualties with a field pattern military tourniquet left unreleased for several hours. It may be preferable to perform primary amputation at the scene as a life saving measure. The seriously ill casualty with multiple injuries: In selected cases, amputation may be the simplest and fastest means of removing damaged, necrotic life-threatening tissue.

Level of amputation 1107 The following should be considered: • The injury dictates the level of bone division. The level of Initially, it should be performed as distally as amputation may possible and at a level where the tissues appear need revision. viable (Figure 1102). This may be suboptimal for This can be function and require subsequent revision. performed at the time of delayed • Attempt to retain the knee joint in order to primary closure or achieve a more functional stump. The medial weeks or months head of gastrocnemius is often sufficiently later when a prosthesis is preserved to provide soft tissue cover for a being considered. below knee amputation. Where this cannot be 231

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The three aims of achieved, it is better in an emergency to primary amputation are to: amputate through the joint rather than through the lower femur. 1.Save life. 2.Excise all • To release a trapped casualty, perform a dead, contused and guillotine amputation as distally as possible. contaminated tissue. • To prevent infection, remove all dead 3.Facilitate delayed tissue/foreign material. Remember that each primary closure. limb has a number of separate longitudinal compartments. Blast injury typically drives fragments of boot, dirt and clothing far up these fascial planes.

Operative technique in emergency amputation

1108 Essential points are: • Resuscitation should continue during surgery to ensure adequate urinary output. • A well-padded, proximal thigh tourniquet should be applied, but not necessarily inflated, during removal of field dressings and subsequent surgery. • Perform under GA; Ketamine (0714) can be used in the field. • Identify and control the main vessels using artery forceps. Once the level of the amputation has been determined, the arteries and veins are individually doubly ligated with Prolene and divided. If uncontrollable bleeding is encountered, inflate the tourniquet and secure the vessel. • The skin incision is often dictated by the wound. Retain as much viable skin as possible. Unequal flaps are often constructed so that the final scar will avoid the end of the stump. • Incise the deep fascia at the same level as the skin and reflect it up as a single layer. Do not 232

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dissect unnecessarily between skin and deep Preserve as much viable skin, muscle fascia. Leave viable muscle for at least 5-10cm and bone length as distal to the proposed level of bone section. you can without Nerves should be cut with a sharp blade under endangering the gentle traction at the level of amputation so that casualty's life. they retract proximally away from the stump. • Excise all dead tissue, remove foreign material and copiously irrigate the wound, (0503). • Divide the bone with an amputation or Gigli saw. Avoid damage to soft tissues by using a guard or Never perform swab wrapped around the wound. File any sharp a primary stump bone edges. It is not necessary to reflect a closure following amputation in periosteal cuff. the field. • If a tourniquet has been used, it should now be released and all bleeding points secured. • Perform further irrigation. • Loosely pack the wound with fluffed, dry gauze to encourage free drainage and absorb exudate. Flaps should be allowed to fall into place without Following a blast kinking: do not suture. Avoid soaking the injury, the other limb dressings in antiseptic solution. Cover the frequently requires surgical treatment. stump with two thick layers of cotton wool placed crosswise and secure with a crepe bandage (Figure 1103). Below knee amputations should be splinted with the knee in extension so as to prevent flexion contracture.

Preventing retraction Muscle retraction results in a conical 1109 In order to prevent skin and muscle stump with retraction where the amputation flaps are scanty or inadequate cover of the bone, making closure is delayed, apply gentle skin traction. Attach prosthetic fitting sterile adhesive tape to the skin above the amputation difficult and level. Fix by means of a stockinet cuff to a Kramer revision amputation wire cage incorporated in a plaster of Paris cast a possibility. over the stump.

233

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Layers of cotton wool placed crossways

Dry fluffy gauze in open wound

Crepe bandage

Wide sticky tape

Fig 1103 Stump bandage (BKAs are splinted using a back slab or split plaster cast).

Casualty Transfer

1110 Once the casualty's condition has been The dressing often becomes offensive stabilised following emergency amputation, transfer. in the time before Splint the limb and provide adequate analgesia. delayed primary If transfer is prolonged, immobilise the stump in closure. This alone a well-padded plaster of Paris back slab or cast. is not a reason to suspect stump This must be split, easy to remove and not infection or interfere with wound drainage. Important details re-explore. of the procedure can be written on the cast as well as in the notes. Use splints to prevent ankle and 234 wrist contractures.

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1111 Redressing during transfer is only indicated if the casualty develops severe wound pain or significant pyrexia. Ideally, this should be carried out in theatre under sedation or anaesthesia. The usual causes are stump swelling within tight dressings or infection.

1112 Where the casualty is a civilian, further treatment may have to be delegated to local or charitable facilities. Bear in mind the quality of on-going local care available to civilians, when planning an amputation.

Delayed Primary Closure

1113 At around 5 days after amputation, If nothing else is the stump is re-examined in theatre under GA available, the side or Ketamine. By this stage, granulation tissue will of a sterile glove normally have started to appear. Lack of tissue can be used as an improvised Penrose- cover or prosthetic considerations may necessitate type drain. an amputation at a higher level. As long as the wound looks clean and healthy, delayed primary closure can be safely performed. If in doubt, re-examine 48 hours later.

1114 Where it has been possible to leave enough muscle at the primary operation, a myoplastic closure is performed: • Opposing muscle groups are sutured to the bone end using a strong, braided absorbable suture (e.g., No 1 Vicryl). The aim is to provide coverage, strengthen the stump and optimise function (Figure 1104). • Drain the wound using a closed suction system; this can usually be removed 24 to 48hrs later. • The deep fascia is approximated with Vicryl and the skin with interrupted nylon mattress sutures or clips. 235

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Fig 1104 Myoplastic recontruction.

• Apply a firm stump bandage. • The wound is inspected 7-10 days later, by which time sutures can usually be removed.

1115 The use of split skin grafts to cover the wound may permit a lower level of amputation. If employed on weight-bearing areas, these will subsequently require replacement (1117). Alternatively, if there is insufficient skin to cover a myoplastic closure, leave it exposed. Once the swelling subsides, the defect usually closes rapidly.

Principles of the Final Amputation

1116 Following emergency amputation, further The aim of the final amputation is surgery may be required. Ideally, this is deferred until to produce a the wound is healed and the casualty is being well-formed assessed for prosthetic fitting. and controlled amputation stump that is suitable for 1117 Damaged areas of the stump which are limb fitting. essential for weight bearing may need to be covered by full thickness, rotation, advancement, transposition or pedicle flaps (2310). In non weight-bearing areas, 236 split skin grafting may suffice. Few modern

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2/3rds Length

4 -5 cm Flap 10 cm

2/3rds 3 -4 cm Level of wrist Length Flap disarticulation

Fig 1105 Upper limb: division of bone and construction of skin flaps.

prostheses are now end bearing, most rely on circumferential support.

1118 Specialised bone transport techniques are available at Role 4 to lengthen an inadequate stump.

Specific Regions

Upper limb

1119 In the upper limb there is no optimum level In the arm conserve of amputation, the bone being divided as low as every centimetre of possible. Preserve as much of the hand as you are length, in the leg do a standard able, particularly the thumb. Even a short thumb amputation. stump can act as a grip post. Surplus dorsal skin may be used to provide cover. Complications are less common after upper than lower 1120 Above the wrist, the bones are cut cleanly limb amputation. and the edges filed smooth. Opposing muscle groups and tendons are sutured over the bone ends. Ideally, cover with equal anterior and posterior skin flaps (Figure 1105). 237 Chapter_11.qxd 28/09/2004 15:55 Page 238 11: Amputation

Flap length 10 cm Division of femur 12-15 cm above knee

Fig 1106 Above knee amputation.

Lower limb

Above knee amputation (AKA) 1121 Technique: • Divide the femur 12-15 cm above the knee; bevel the bone end. • Construct semi-circular shaped anterior and posterior flaps with their longest point just above the knee (Figure 1106). The aim is to have a flap length such as to offset the final scar away from the point of the stump. • Divide the quadriceps tendon above the patella and the hamstrings at their insertions. • The muscle groups are fixed to the end of the femur using Vicryl sutures passed through drill holes 1 cm from the bone end. 238 Chapter_11.qxd 28/09/2004 15:55 Page 239 11: Amputation

5 cm

10 cm

Fig 1107 Through knee disarticulation.

• The skin is closed over a drain. • Do not worry about the bulky stump, this will resolve with the application of a stump dressing and subsequent muscle atrophy.

Knee disarticulation 1122 This is rarely performed other than as an emergency: • Construct anterior and posterior skin flaps; the anterior should end 10cm below the knee and the posterior 5cm (Figure 1107). • Free the patella tendon from the tibial tubercle and dissect upwards to reveal the knee joint. • Cut the cruciate ligaments level with the tibial plateau and the muscles at their insertion. • Suture the hamstring tendons and the patella tendon to the stumps of the cruciate ligaments and nearby tissues. • Most knee disarticulations are later converted to above knee amputations. 239

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11 - 15 cm

30 cm

Skin incision NB. Long posterior flap

Fig 1108 Below knee amputation.

Below knee amputations (BKA) 1123 Technique: The safest • The tibia is ideally divided 15cm below the knee elective technique for a below knee and the fibula 2cm more proximal (Figure 1108). amputation in the field is to use a • Cut the anterior part of the tibia at an angle to 15cm tibial stump avoid a sharp edge. and add 15cm to this for the posterior flap. • Leave a long, posterior musculo-cutaneous flap extending 15cm beyond the divided tibia. • Anteromedial and anterolateral drill holes are made in the distal 1 cm of the tibia and the muscles sutured to these using Vicryl. • Some filleting of the soleus and gastrocnemius muscle bulk may be necessary. • The skin and deep fascia are divided so that the wound comes to lie over the front of the bone.

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Archillis tendon

Shin incision

Talus

Trimmed medial and lateral malleoli

Fig 1109 Syme amputation.

Ankle 1124 The Syme operation is recommended for ankle amputations (Figure 1109): • Divide the malleoli level with the articular surface of the tibia. 241 Chapter_11.qxd 28/09/2004 15:55 Page 242 11: Amputation

• Fillet the heel pad off the calcaneus, pull this forwards to cover the bone ends and suture anteriorly.

Foot 1125 Satisfactory function is possible with amputations as proximal as the bases of the metatarsals: • Try to salvage the medial or lateral borders of the foot. • Avoid sectioning through the hindfoot or tarsus; muscle imbalance will result in a tilted stump.

Rehabilitation and Revision

1126 A below knee stump should be held in extension to avoid flexion contractures during the early healing phase. Adjuncts include passive stretching and the use of sandbags. Start quadriceps and hamstring exercises with knee flexion as soon as possible. The casualty should start mobilising with a training prosthesis or pylon within the first two weeks.

1127 Revision of the stump may be required months or years later. Indications include: • To facilitate fitting of a prosthesis. • Neuroma. • A painful scar tethered to bone. • Chronic sinus from non-absorbable sutures. • Sequestrum formation. • Sharp or protruding bone end. • Growing bone in children.

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Abdominal Injuries

Introduction

1201 Abdominal wounds are challenging; they challenge the life of the victim and the skill of the The frequency of medical team. In contrast to UK civilian practice, abdominal visceral where 90% of abdominal injury is due to blunt trauma, damage as a result penetrating injuries predominate on the battlefield. of penetrating chest, They account for approximately 10% of all wounds flank or back injury ranges from 10-50% and can be associated with mortality as high as 40%. depending on the Fragments are the most common cause of injury but available energy bullet wounds are the most lethal. of the missile. Haemorrhage, often occult and always non-compressible, is the usual cause of death during the first 24 hours. Subsequent mortality occurs as a result of missed or delayed bowel perforation, development of sepsis, secondary haemorrhage and multi-organ failure. The majority of abdominal wounds require surgery. (UK data from WWII suggest, in 10% of laparotomies for penetrating ballistic trauma, the peritoneum was not breached). Recognising the possibility of intra-abdominal injury followed by careful resuscitation, early transfer, appropriate surgery including damage control surgery and skilled nursing, are prerequisites for a successful outcome following these injuries.

Pathophysiology of Abdominal Injury

1202 High available-energy missiles entering the abdomen are associated with long wound tracks, yawing, fragmentation and serious visceral injury (0203). They often travel an unpredictable route from their point of entry particularly, if they strike bone. 243

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Where cavitation has occurred in solid organs, mortality is significant (0207). Anti-personnel fragments and handgun bullets typically, but not always, cause low energy-transfer injury confined to the wound track (0203). Casualties who have experienced significant deceleration or deformation forces are likely to have sustained visceral disruption (0201). Blast injury typically causes multiple haematomas and tears in the wall of hollow viscera (0218). These haematomas can cause obstruction, notably to the duodenum, and may rupture up to 14 days later. Crushing is likely to damage fixed organs, whilst shearing causes mesenteric tears and disruption or avulsion of major blood vessels.

1203 Patterns of blunt injury are typically recognised: steering wheel and seat belt trauma results in damage to the myocardium and great vessels, the liver and spleen. Similarly, a fall from a height of >5m may fracture the pelvis leading to urethral and bladder injury, avulsion of the renal pedicles and diaphragmatic rupture.

Initial Management in the Field

1204 Principles include: • ABC: Abdominal injury is mainly a 'C' problem. • Assessment of circulation: this is performed during the 'C' phase of the primary survey. The history and a quick examination (0313) may provide clues indicating probable abdominal injury. • Abdominal trauma is likely to cause non- compressible haemorrhage. Organise urgent transfer to a surgeon. Start hypotensive resuscitation (0333). 244

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• Perform a full physical examination during the secondary survey to include: the back, lower chest, pelvis, perineum and rectal and vaginal examinations, (PRE and PVE). An absence of physical signs does not mean an absence of intra-abdominal injury (1205). The abdomen is a silent reservoir for blood loss. • Analgesia (Figure 0701). • Antibiotics (0817) • Casualty packaging for transfer: • Wound dressings: in bleeding wounds, Where non-compressible a degree of tamponade may be achieved abdominal by packing two or more field dressings into haemorrhage the wound. If they become heavily soiled, is suspected, putting additional dressings can be applied on top up drips, completing the secondary (NB: record the number of dressings used). survey etc., should Secure dressings around the trunk in a way not delay casualty that does not embarrass respiratory function. transfer to a surgeon. Research suggests • Eviscerated bowel: should be irrigated that delay caused with sterile fluid and gently returned to by initial attempts the abdomen before application of field at management in the field dressings. If this is not possible, cover increases mortality. with a moist field dressing to prevent drying. Where there is leakage of bowel contents, the damaged segment should be isolated outside the abdomen by wrapping it in a field dressing, polythene bag or similar. • Fluid restriction: keep casualties 'nil by mouth' (NBM). Sips of water <30mls/hour are permitted to moisten the mouth. If transfer is delayed and i.v. infusion unavailable, give oral or nasogastric fluids (up to 500ml/hour). Absorption from the proximal small bowel is usually maintained during the early stages after trauma. • Position: casualties with abdominal wounds may be more comfortable nursed in a 'W' 245

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The exsanguinating position i.e., lying with knees drawn up casualty who is not responding to i.v. and shoulders raised; or on their side in fluids and has no the foetal position. This reduces tension evidence of on the anterior abdominal wall and may extremity, chest prevent evisceration. or pelvic bleeding, requires an • Documentation: 'MIST' (0301). immediate laparotomy during • Decompression: If conditions permit, pass the primary survey a nasogastric tube and bladder catheter. to stop the bleeding. • Monitor and prevent hypothermia.

Management at a Surgical Facility (Roles 2+ and 3)

1205 On arrival, casualties must undergo further triage. A surgeon should be involved early in any decision-making process - laparotomy may be the next step in resuscitation.

Assessment of abdominal injuries

Where the cause History of shock is unclear, examine the casualty • Time of wounding. in general and the abdomen in • MIST (0301). particular and do • Path of missile: knowing the casualty's position it repeatedly. when hit and the direction of travel may provide an indication as to the internal path of the missile. But, this can be notoriously misleading! Multiple hits mean multiple possibilities! • Pain: is it localised, generalised or referred? Shoulder tip pain may be referred from a subdiaphragmatic haematoma or abscess. • Blunt trauma: knowing the vectors of the forces involved and their direction ('reading the wreckage') can help predict organ damage (patterns of blunt injury - see 1203). 246

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• Features of blast injury may include abdominal pain, vomiting, haematemesis, rectal bleeding - fresh blood or melaena - and tenesmus. Absence of blast injury to the eardrums does not equal absence of blast injury elsewhere.

Examination 1206 Routine examination includes: Abdominal • Inspect the abdomen, lower chest, back, examination is often buttocks, perineum and thighs for penetrating unreliable, especially wounds, bruising (e.g., tyre or seat belt marks) following blunt and swelling. This may point to which organs are trauma. A negative examination does affected. Restricted abdominal wall movement not exclude with respiration suggests abdominal wall injury, significant injury. peritonitis or spinal trauma. Early transfer on suspicion of • Palpate. The presence of tenderness, rebound abdominal trauma and guarding are diagnostic of peritonitis. NB: alone is appropriate. tenderness is often minimal or absent during Delay until signs become obvious the initial stages of intraperitoneal haemorrhage. will result in mortality Check the perineum, genitalia and perform a PRE rates over 90%. and PVE. This may draw attention to a fractured pelvis (1312) or ruptured urethra (1423). • Percuss. Suprapubic dullness suggests Abdominal distension alone an enlarged bladder: is the urethra injured? is a poor indicator Dullness in the flanks can be a sign of blood of intra-abdominal in some quantity in the paracolic gutters. pathology. • Auscultate. Minimal or absent bowel sounds suggest abdominal trauma or ileus from other causes e.g., spinal cord injury and retroperitoneal haemorrhage. • Associated injury. Examine the chest, vertebral column, spinal nerves, pelvis and lower limb vessels. A reduced pulse volume over one femoral artery suggests iliac artery damage.

Investigations

1207 The presence in the field of a variety of 247

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The results of DPL investigative tools should not become an excuse for after major pelvic fracture can be delaying surgery, especially when surgery is definitely confusing. Blood indicated on clinical grounds alone. The unique tends to track conditions under which military surgeons are extra-peritoneally required to work, mean they must learn to place up the anterior abdominal wall. robust reliance on their own clinical judgement. Under such This particularly applies to the assessment of circumstances, abdominal injury, where delay in surgery for some, a supraumbilical can be fatal. Delay should not be compounded by approach is recommended. unnecessary investigations.

1208 If the diagnosis or magnitude of intra- Deaths due to abdominal injury are in doubt and the casualty is sepsis may occur as a result of missed stable, investigations at Roles 2+ and 3, may aid retroperitoneal management. But, if laparotomy is indicated, that is injuries to the the only investigation necessary! duodenum, colon, pancreas, urinary tract and rectum. 1209 X-rays: are routinely performed in the initial assessment of polytrauma (0336). Significant findings Peritoneal lavage: include: the presence of intra-abdominal foreign - Catheterise. bodies on two views (a single view will not exclude - Clean and infiltrate foreign bodies in the abdominal wall), or free gas with 1% Lignocaine under the diaphragm. Injuries that cause fractures in the midline 2.5 cm below the umbilicus. of the lower ribs, lumbar spine and pelvis, indicate - Have a small the likelihood of intra-abdominal injury. incision down to peritoneum. 1210 Sigmoidoscopy: is used to assess rectal - Insert a peritoneal injury where PRE demonstrates bleeding. dialysis catheter. - Infuse 500 ml of 1211 Contrast studies: a swallow/meal or warm saline enema, are simple and rapid methods of detecting - Tilt casualty to distribute fluid. visceral leakage: use a water-soluble contrast medium. - Lower the infusion back to allow fluid to 1212 Diagnostic peritoneal lavage (DPL): may drain back. be employed to detect blood or visceral perforation. Points to note:

• Following blunt abdominal trauma, DPL has a sensitivity of 95% and specificity of 99%.

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of macroscopic blood, bile or bowel contents; or a laboratory analysis of aspirated fluid that shows one of the following: >100,000 rbc/mm3, >500wbc/mm3, an amylase of >175iu and the presence of vegetable fibres. • Relative contraindications to DPL include previous abdominal surgery, obesity, pregnancy, cirrhosis and coagulopathy. • DPL has little diagnostic value in assessing penetrating trauma and is generally inappropriate: the majority of casualties require laparotomy.

1213 Focused abdominal sonography for trauma (FAST): is used to detect free fluid in the Imaging difficulties peritoneal cavity and pericardium. for FAST may be due to rib shadowing, • It is quick, non-invasive and now widely used obesity, intestinal gas in place of DPL. It is the immediate investigation and subcutaneous of choice in unstable casualties with suspected emphysema. or actual blunt abdominal trauma. • When performed by trained personnel a sensitive of 88% and specificity of 90-99% has been reported following blunt trauma. • It is usually only possible to detect blood volumes >100ml. • Where positive, the casualty will require laparotomy. By comparison, a negative result does not exclude intra-abdominal injury, it should be repeated or the findings confirmed by DPL or CT.

1214 Computerised tomography (CT): in civilian practice, this is regarded by many as the investigation of choice in stable casualties following major blunt trauma. Although scanners are now robust and can be moved relatively easily, their use in the field to date is limited.

• Modern scanners are quick and have a 249 Chapter_12.qxd 28/09/2004 15:55 Page 250 12: Abdominal Injuries

sensitivity of 88% and specificity of 98%. They are accurate for assessment of solid organ and retroperitoneal injury. Features of intestinal injury seen on scanning include: free gas, large collections of peritoneal fluid and thickening of bowel wall and mesentery. • Scanning is undertaken from the dome of the diaphragm to the symphysis pubis. • When performed after administration of a contrast enema, it can be used to exclude a retroperitoneal colonic injury in a casualty with a posterior abdominal wound.

1215 Laparoscopy has been used at Role 3 to detect bleeding, organ damage (e.g., diaphragmatic tears) and identify bowel perforation. Combinations of laparoscopy and ultrasound scanning (USS) are being used to effect control of bleeding from solid organs. USS can be modified to both, detect and control, sources of haemorrhage.

Surgical decision-making When assessing casualties with suspected abdominal injuries, the surgeon must answer five questions: 1. Does the injury involve the peritoneal cavity? 1216 Suspicious or absolute features include: Bowel sounds may be present despite • Penetrating wounds in the vicinity of the intestinal perforation. abdominal cavity - nipple to perineum - or, in the case of gunshot wounds, nipple to knees. • Protrusion of bowel or omentum. • A heavily bleeding wound or one discharging intestinal contents, bile, pancreatic juice or urine. • Peritonitis. • Unexplained hypovolaemic shock especially with failure to respond to resuscitation; unaccountable 250 Chapter_12.qxd 28/09/2004 15:55 Page 251 12: Abdominal Injuries 12: Abdominal

vomiting or a casualty whose condition is Probing the wound is an unreliable proportionately worse than the wound method of detecting would suggest. a breach in the peritoneum and is • Absent bowel sounds. not an alternative to laparotomy. • Positive investigations (1207). Similarly, because the relationship of 1217 Decision-making can be difficult in: the layers of the abdominal wall to • The unconscious or confused casualty. the underlying viscera is likely to • Retroperitoneal perforation: in the absence of be different at the leakage into the peritoneal cavity, clinical signs time of wounding, may initially be absent. probing can not reliably tell you • Spinal cord injury. the direction of the wound track. • Superficial wounds confined to the abdominal wall. Diagnostic features may include minimal shock, improvement with observation and continued presence of bowel sounds. • Thoracic trauma: abdominal rigidity may occur following thoracic injury. It can usually be differentiated from that due to peritonitis by Unrecognised its variability during respiratory movement. abdominal injury is a common cause of preventable death. 2. What structures are likely to be injured? In up to 50% of casualties with 1218 This can be guessed at from the history significant (1205) and examination (1206). If the casualty is intraperitoneal stable, consider appropriate investigations (1208). haemorrhage, seen at Role 1, physical signs will be few 3. Does the casualty need an operation? or absent. 1219 The majority of casualties in whom a penetrating injury of the abdominal cavity is proven Laparotomy in the or inferred, will require a laparotomy. Circumstances presence of lung where surgery may be delayed include: or cardiac injury carries a high • No clear evidence of damage to intra-abdominal morbidity and mortality. viscera. Such cases should be observed, repeatedly examined and have appropriate investigations (1208). 251 Chapter_12.qxd 28/09/2004 15:55 Page 252 12: Abdominal Injuries

• Where injuries are so severe that recovery is unlikely. Triage category is then T4 until all other casualties have been treated. • Casualties who have remained stable for more than 18 hours. Those who have survived so long without medical aid have usually succeeded in localising their injuries and conservative treatment may be appropriate. Moribund cases should be made 4. Who to operate on first? comfortable and treated expectantly. 1220 Generally, casualties with abdominal injuries Included in this require surgery as soon as possible. The optimum group may be some casualties with should be aimed at restoration of a normal circulating multiple injuries, volume and surgery proceeding in parallel. Unstable established casualties, who need urgent laparotomy as part of peritonitis, endotoxic the primary survey and, given other injuries, have shock and failing peripheral circulation. a good chance of survival, take precedence. They may be The surgeon has to decide priority. Cases where mentally alert but are haemorrhage is the main problem take precedence frequently in pain over intestinal perforation. and restless. 5. Which injury to operate on first? 1221 In a casualty with multiple injuries it can sometimes be difficult to prioritise the approach. • Thoracic injury and controlling exsanguinating peripheral haemorrhage take precedence over abdominal trauma. • Management of the abdomen takes precedence over head, spinal, pelvic and non-exsanguinating limb trauma. • When it is necessary to undertake surgery on both the front and the back, the latter should generally be performed first. Experience has shown that turning a casualty face down after a laparotomy can cause profound hypovolaemic shock due to pooling of blood in the splanchnic circulation. 252 Chapter_12.qxd 28/09/2004 15:55 Page 253 12: Abdominal Injuries 12: Abdominal

• Where major wounds co-exist with abdominal In 20% to 40% of laparotomies trauma, for instance, a limb requiring amputation, performed for a second surgeon should operate simultaneously. presumed intra-abdominal • Antibiotics given within the first hour after injury bleeding, usually allow excision of soft tissue wounds haemorrhage to be delayed. These injuries presenting in is found to combination with an abdominal wound, have stopped spontaneously: but, can wait until the casualty is stable. better a negative laparotomy than Local factors affecting surgical prioritisation. a dead casualty. 1222 A Unit may become overwhelmed by more casualties than it can deal with in a reasonable time span. Also, there may be staff fatigue and lack of re-supply of equipment. Options then include: • Avoiding protracted surgery in favour of simpler and quicker operations. • Sending those who are in the best state to withstand a journey to another Unit. • Conservative treatment. In civilian practice, approximately 8% of casualties with perforations of the small, or even the large bowel, recovered spontaneously on supportive treatment. The problem with this approach in a field setting is the ability to observe casualties closely enough for long enough.

Operative Considerations Laparotomy for Resuscitation prior to abdominal surgery exsanguinating haemorrhage is futile 1223 The aim of resuscitation is to get the if the casualty has casualty into the operating theatre in a condition already suffered a that will allow the surgeon time to find and control cardiac arrest. bleeding. Experience has shown that a limit of 2 hours should be set upon resuscitation; it must be actively supervised. Shock in an abdominal casualty is due to: 253

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• Loss of blood. • Dehydration from sweating and diminished fluid intake during fighting. • Loss of plasma from other wounds and into the peritoneum. • Sequestration of fluid in the small intestine. • Toxaemia from early infection. A casualty with abdominal wounds who is severely shocked is nearly always suffering from ongoing blood loss. This is likely to continue until the bleeding is controlled. Such casualties require immediate operation for resuscitation rather than resuscitation for operation. Blood transfusion should be available whenever abdominal surgery is contemplated. In Grade III or IV shock (Table 0301), type-specific blood is used until cross-matched units become available. The rate of transfusion prior to operation depends on the initial response to resuscitation. Where there has been a response, blood should be infused at such a rate that the systolic pressure is maintained at ~90mmHg. Where the casualty remains unresponsive, they should be rapidly transferred to the operating theatre.

Damage control surgery 1224 Visceral damage following high-energy penetrating or blunt abdominal injury is typically extensive. Damage control surgery to control bleeding and prevent peritoneal soiling may be appropriate (0403).

General plan for emergency abdominal surgery 1225 Stages include: • Position the casualty supine on the operating 254 table. Apply warming devices to the extremities and upper body, including the head. Pass a

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bladder catheter and nasogastric tube. Administer antibiotic prophylaxis i.v. at the start of surgery (0817); start DVT prophylaxis (0980). General anaesthesia with muscle relaxation is needed for optimum operating conditions (2501). Clean and prepare the skin. Drape the torso so that the incision can be extended into the chest and groins (Figure 0402). Have two working suckers, large packs and vascular clamps available. • In most cases, gain rapid entry through a full-length, midline incision. Skirt around or excise skin wounds. • Situation permitting, carry out toilet of the abdominal cavity. • Carry out a systematic identification and arrest of haemorrhage. • Do a systematic search for intra- and retroperitoneal organ damage. • Repair: where appropriate, confine your operation to damage control surgery (0403). • Perform a final peritoneal lavage. • Use drains only when indicated. • Mass closure: close the rectus sheath with a continuous, non-absorbable suture. There is no need for separate closure of the peritoneum. Perform a temporary closure following damage control surgery where re-laparotomy is required or, if there is risk of the casualty developing an abdominal compartment syndrome. (1290). • Monitor temperature, pulse, BP and fluid input/output. Continue i.v. fluids. Restrict oral fluids for the first 36-48 hours (30mls per hour) then gradually increase them unless contra-indicated by the presence of ileus. Pressure area care and physiotherapy are no less important in a military setting than 255 a civilian one.

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• Where there has been major faecal contamination after colorectal surgery, give 2-3 doses of co-amoxiclav 1g i.v. (0817) every 8 hours for the first 24 hours. Continue for 2-5 days if there is a significantly increased risk of infection.

Incision 1226 A midline incision from xiphisternum to pubis is the standard approach to the abdomen in military Remember, there may be more than surgery. It is rapid, relatively bloodless and gives one bleeding site. good exposure. Catheterise the bladder before making the incision. • The wound can be extended laterally or continued into either hemithorax by curving the incision across the costal margin into the 5th or 6th intercostal space. Divide the diaphragm circumferentially 3cm from its attachment with the chest wall to avoid damaging the phrenic nerve. This incision can also be extended as a sternotomy. • A right thoraco-abdominal incision gives access to the subdiaphragmatic surface of the liver and the Inferior Vena Cava (IVC), on the left it gains an approach to the thoracic aorta and distal oesophagus. • In a small number of cases it will be sufficient to extend the primary wound but, always be prepared to enlarge the incision.

Systematic identification and arrest of bleeding 1227 Following blunt trauma, the site(s) of Once bleeding is controlled, allow the bleeding can be obvious and amenable to rapid transfusion to begin control. This is far from true for penetrating injury, catching up with where damage to several viscera and/or vessels, is blood loss before the norm. In this case, it is necessary to insert large continuing with 256 the operation. packs to isolate the abdominal compartments where

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blood collects (Figure 0403). Do not waste time trying unsuccessfully to deal with one bleeding point when the abdomen is full of blood; there is likely to be more than one source of bleeding. Pack the abdomen systematically: • Pack the right upper quadrant above the right lobe of the liver, then retract the hepatic flexure of the colon downwards, the liver upwards and explore and pack the space under the right hepatic lobe lateral to the duodenum. • To pack the left upper quadrant and over the spleen: retract the stomach medially and the splenic flexure of the colon downwards to expose the area under the left lobe of the liver and around the spleen. • Right and left infra-colic compartments: lift the transverse colon, omentum and small bowel. Explore and pack the spaces medial to the right and left sides of the colon along each leaf of the small bowel mesentery. • To pack the rectovesical pouch: Tilt the table head down and retract the small bowel upwards. Careful removal of each pack in turn will enable the source of the bleeding to be traced and controlled. Where the abdominal cavity is full of blood, the most likely sources are: • Multiple vessels in the small bowel mesentery. • Liver. Occlusion of the thoracic or • Spleen. abdominal aorta for 5-10 minutes may be • Kidneys. sufficient to allow BP to be restored and • Pancreas. the bleeding site to be identified and • Retroperitoneal vessels. controlled. 1228 Emergency control of haemorrhage is by finger pressure, packing with swabs, a carefully placed vascular clamp or balloon catheters (0407). 257

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Occasionally, aortic cross clamping is required (1276). Bleeding points should be ligated or under run with a stitch. Essential blood vessels e.g., the superior mesenteric artery, require repair or insertion of a temporary shunt (0411). Always check the circulation to the gut following control of mesenteric bleeding; absent arterial pulsation and cyanosis are indications for gut resection or major vessel exploration. Retroperitoneal haematomas are generally managed by packing (1274).

Systematic search for organ damage 1229 Perform a systematic examination of the intra- and retroperitoneal organs (Figure 0404). The following is one suggested method: 1. Small bowel and mesentery: examine from the During the ileocaecal valve to the ligament of Treitz. Look at systematic search temporarily close any one side on the way up and the other on the way bowel perforations down (assessment of bowel viability - see 1232). using Babcock's forceps, swabs 2. Colon and rectum: start with the caecum and or tapes to reduce work distally. Where you suspect retroperitoneal leakage. Delay repair damage, divide the peritoneum along the lateral or resection until the extent of the damage reflection and lift the colon forward for inspection. is known. Mobilisation of the rectum requires incision of the pelvic peritoneum. 3. Spleen, left diaphragm, stomach and In the field, gastro-oesophageal junction: where indicated, avoid exploring a divide the gastro-colic omentum to inspect the non-expanding retro-peritoneal posterior wall of the stomach (1255). haematoma - most are managed 4. Liver, right diaphragm and biliary tree. by packing. 5. Duodenum: inspect the four parts. Where indicated, Kocherise the second part of the duodenum (1262) to inspect its posterior surface. 6. Pancreas. Anterior and posterior surfaces of the head of the pancreas are exposed as for 258 duodenal examination. The body and tail of the Chapter_12.qxd 28/09/2004 15:55 Page 259 12: Abdominal Injuries 12: Abdominal

pancreas are inspected through a window made in the gastro-colic omentum (1255). The posterior wall is approached by mobilising the spleen, tail and body of the pancreas to the right. 7. Retroperitoneum and pelvis: Bleeding from pelvic fractures can track in a cranial direction through the layers of the anterior and posterior abdominal walls.

Drainage 1230 A drain may reduce peritoneal soiling. Only use them when there is likely to be something to drain! • Position drains close to the operative field or at known sites of fluid collection - paracolic gutters, subdiaphragmatic and subhepatic areas and recto-vesical pouch. • Use a closed system: a silastic suction drain or tube drain connected to a bag. • Place the openings so that drainage under gravity is facilitated. Bring the drain out through a separate incision. • Drains should be removed when they are no longer draining.

Wound closure 1231 Steps include: • Excise penetrating wounds that lie in the line of the incision. • Wash the peritoneal cavity thoroughly with 4-6l of warm saline. Remove any gross fibrinous exudate using swabs. • A secure, rapid method of closing the deep layers of the incision is using a mass closure technique employing continuous No 1 looped 259

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monofilament nylon or PDS (3027). • The skin edges can be brought together using staples or a continuous monofilament suture (3027). • If severe contamination of the operative field has occurred, as in heavy and prolonged faecal soiling following delayed surgery for a large bowel perforation, close the deeper layers but leave the skin open for delayed primary suture five days later. • When re-laparotomy is planned, or it is necessary to leave the abdomen open as a laparostomy, carry out temporary closure as described in 0412. This will reduce heat and fluid loss from the open wound. It also aids nursing care. • Where the defect is too big to close, various plastic and other procedures are available including flap repair (2310), insertion of nylon mesh or allowing the wound to granulate. These should be carried out in a plastic surgery unit at Role 4 hospital.

Regional Injuries

Small bowel Introduction 1232 The small intestine and mesentery are the most frequently injured part of the gut, damaged in >30% of penetrating abdominal wounds. The majority of wounds are multiple. For this reason, resection is often safer and quicker than individual wound repair. Perforations are often small, impalpable and easily missed. Bleeding is usually from the mesentery rather than the gut and often stops spontaneously. Small bowel contusions of <15mm diameter and non-expanding 260 haematomas in the mesentery, can be left

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undisturbed. A mesenteric haematoma extending to the bowel wall may be the only sign of a perforation, they should be explored. The presence of a haematoma may also indicate compromise to the blood supply of the gut adjacent to the haematoma. Check gut viability again before closing the wound. If in doubt, release the haematoma, control any bleeding and check the viability again. If there is still doubt, resect the small bowel. Multiple small bowel resections may critically compromise small bowel length and function. Faced with this problem, an alternative is to leave possibly ischaemic gut and check its viability at a 'second look' procedure 24 hours later. Assessment of bowel viability includes: • Colour. • Sheen. • Peristalsis. • Mesenteric pulsation. • Free bleeding from transected ends.

Single perforation

1233 These usually require minimal wound Using 3.5mm skin excision (Figure 1201). staples to repair defects or • Place stay sutures. anastomose bowel is rapid • Close transversely using a single layer of and effective. interrupted or continuous sero-submucosal (extramucosal), inverting sutures placed 5mm apart (1202 D). Use 3/0 absorbable sutures on a round-bodied needle or 3.5mm skin staples. The technique for the latter is exactly the same as for sutures. The stay sutures, when pulled apart, help to invert the defect allowing for a serosa-to-serosa closure.

• Contused areas >15mm in diameter should be 261 invaginated and oversewn, or excised and the A B C D Fig 1201A) minimal wound Simple repair of small laceration: excision. B) insertion of stay sutures. C) transverse repair using interrupted, serosubmucosal inverting sutures. D) completed repair.

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bowel closed transversely. • Normal small bowel has an excellent blood supply and most wounds heal without complications.

Indications for resection 1234 These include: • If simple suture is mechanically unsatisfactory; this applies when a group of perforations are so close that individual repairs would overlap. • When excision and re-anastomosis saves time. • There is injury to the mesenteric border. • When the gut is ischaemic.

Standard end-to-end anastomosis 1235 Steps are (Figure 1202): • Select a healthy segment of bowel either side of the damaged area. Occlude the lumen using pairs of inner (crushing) and outer (non-crushing) bowel clamps. • Ensure a wide lumen by dividing the bowel at an angle away from the mesenteric border of the retained gut. If the bowel ends do not look pink or fail to bleed when transected, resect more widely. • Ligate and divide the mesenteric vessels. Place two stay sutures on the mesenteric and antimesenteric borders. • Perform an end to end anastomosis using a single layer of interrupted sero-submucosal (extramucosal) inverting sutures placed 5mm apart. Choose a 3/0 absorbable suture on a round-bodied needle. Alternatively, use skin staples or a continuous, inverting Connell stitch. First anastomose one side then turn the bowel over and anastomose the other. 263 Line of resection C B D E A Stay suture Stay Crushing clamp Non crushing clamp Fig 1202 Resection and small bowel anastomosis: A) Division of small bowel between crushing and non-crushing clamps (NB: divide at an angle). B) Place stay sutures. C) Repair front wall first then rotate. D) Use interrupted, serosubmucosal sutures. E) completed repair.

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Fig 1203 Technique of anastomosing bowel ends of disproportionate size.

• If skin staples are used, triangulate the ends of the gut with 3 stay sutures inserted over the clamps. Remove the crushing clamps but leave the crushed ends to maintain haemostasis. Invert each limb of the triangle by pulling apart adjacent stays, then insert 4 to 5 staples per limb and tie the stay sutures. • Finally, to ensure the lumen is patent, gently invaginate the walls of the bowel between finger and thumb. Close the defect in the mesentery using sutures or clips without damaging the blood supply.

1236 Anastomosing bowel of unequal diameter. Where there is disparity in size, use the technique illustrated in Figure 1203. Incise the smaller diameter 265 Chapter_12.qxd 28/09/2004 15:55 Page 266 12: Abdominal Injuries

A

B

C

D

Fig 1204 Stapled anastomosis: A) The bowel is closed and divided. B) The bowel ends are approximated using a stay suture; a small incision is made in each limb. C) The limbs of the stapler are introduced, clipped together and the device fired. D) The remaining defect is closed using a second stapler.

bowel along its antimesenteric border until it matches the larger diameter, then cut the edges of the bowel 266 wall straight before doing the anastomosis. Chapter_12.qxd 28/09/2004 15:55 Page 267 12: Abdominal Injuries 12: Abdominal

A

B

C

Fig 1205 End-to-side anastomosis: A) Close-off the distal limb. Milk the bowel contents away from the closed end and clamp. Make a longitudinal incision over a taenia coli equal to the diameter of the small bowel. Insert stay sutures. B) Anastomose the back wall using vertical mattress sutures. C) Anastomose the front wall using interrupted sero-submucosal sutures.

Alternatively, perform a side to side (Figure 1204) or 267 Fig 1206 Constructing a loop ileostomy: incise so as to construct a proximal spout and suture in place.

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end to side anastomosis (Figure 1205). Stapled anastomosis 1237 The use of stapling devices provides a convenient method of small bowel resection and anastomosis (Figure 1204). • Resect and close the bowel using a linear stapler (e.g., Autosuture™ GIA 60). • Approximate the two bowel segments side-to-side. Hold with a stay suture. • Make a small incision in the antimesenteric border of both bowel segments. Introduce a limb of the stapler through each hole and clip the halves of the device together. "Fire the gun". • Place stay sutures and close the remaining defect (e.g., using a Autosuture™ TA 55).

Loop ileostomy 1238 This may occasionally be required to protect a right-sided colonic repair (Figure 1206). • Lift up a distal loop of small bowel to a convenient site on the anterior abdominal wall, usually the right iliac fossa midway between umbilicus and anterior superior iliac spine. This may be facilitated by passing a rubber sling through the mesentery adjacent to the bowel. Ensure that the orientation is correct and that there is no tension. • Excise a disc of skin. Make a cruciate incision in the underlying fascia, rectus muscle and peritoneum. • Pull the small bowel through the defect and hold this temporarily in place with a colostomy bar. • Open the small bowel transversely as shown in Figure 1206. In order to reduce skin irritation, evert the proximal limb so as to construct a spout. Fix in place using interrupted 3/0 269 Chapter_12.qxd 28/09/2004 15:55 Page 270 12: Abdominal Injuries

Fig 1207 End ileostomy: constructing a spout.

absorbable sutures on a round-bodied needle. • Cover with a suitable sized stoma bag. Remove the bar after one week.

End ileostomy 1239 This may be required in combination with a mucous fistula following a right hemicolectomy when anastomosis is contra-indicated, (1244). • The divided bowel end is brought to the surface via a skin trephine, as in 1238. • Pull the bowel back on itself using Babcock forceps in order to create a 5-7 cm spout (Figure 1207). • Fix in place using interrupted 3/0 absorbable sutures. 270 Chapter_12.qxd 28/09/2004 15:55 Page 271 12: Abdominal Injuries 12: Abdominal

Rectal wounds Colon have a high Introduction morbidity and mortality. They are 1240 Wounds to the colon occur almost as often complicated by pelvic fractures, frequently as those of the small intestine. Though small bowel rarely multiple, they tend to be more serious than perforations, small bowel injury because: urological damage, nerve injuries and • The walls of the colon are thin and haemorrhage from more vulnerable to vascular injury and iliac vessels. subsequent ischaemia. • Colonic injuries are frequently extensive. • Damage is easily missed, particularly retroperitoneal injuries and wounds along the mesenteric aspects of the transverse and sigmoid colon. • The contents usually escape earlier and in greater quantities than small bowel perforations, leading to gross faecal contamination. • Leakage of anaerobic organisms into surrounding tissues can lead to fatal retroperitoneal cellulitis. In civilian practise, many injuries of the colon, both ascending and descending, are dealt with by primary closure or resection and anastomosis, without a covering stoma. There is no reason why this approach could not apply on the battlefield subject to the caveats in 1244. There is one further caveat: continuity of postoperative care. Military casualties tend to be transferred early in the post operative period. Close observation by the operating surgeon may be impossible. Anastomotic leaks and clinical deterioration can go unnoticed until it is too late. This is just one of many unique features of battlefield surgery that can influence decision making.

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Mobilisation of Mobilisation of Mobilisation of descending ascending colon rectum colon

Fig 1208 Incising the peritoneum to mobilise the ascending colon, descending colon and rectum

Features of colonic perforation 1241 These are present or, should be suspected, if there is: • A defect, haematoma, contusion or discolouration of the colon. • Retroperitoneal haemorrhage. • Emphysema (colonic gas) in the region of the ascending or descending colon. • An adjacent wound track especially penetrating back, flank or low, posterior chest wounds. • A faeculent smell or faecal contamination of the peritoneal cavity.

Mobilisation and inspection 1242 Where access to the posterior surface 272 of the ascending and descending colon and Chapter_12.qxd 28/09/2004 15:55 Page 273 12: Abdominal Injuries 12: Abdominal

Retracted omentum

Middle colic artery Marginal artery Superior mesenteric artery Left colic Right colic artery artery

A Ileocolic artery Signoid arteries

Right hemicolectomy Transverse hemicolectomy

Left hemicolectomy Sigmoid hemicolectomy

B Fig 1209 A) Vascular supply to the bowel. B) Standard methods of large bowel resection.

rectum is indicated: • Divide the lateral parietal peritoneum and mobilise the bowel medially (Figure 1208). • Take care not to damage the ureters. These can be identified as they cross each common iliac artery close to the bifurcation. • The posterior surface of the transverse colon is inspected by lifting the greater omentum out of the wound and dissecting in the avascular plane between it and the bowel. 273 Chapter_12.qxd 28/09/2004 15:55 Page 274 12: Abdominal Injuries

+/-

Simple repair Loop iliostomy of laceration

Fig 1210 Closing a simple perforation of the right colon. Where considered necessary, this can be protected by a loop ileostomy.

• The rectum is visualised by incising the pelvic peritoneal reflection. The arterial supply of the large bowel is shown in Figure 1209.

Simple colonic repair 1243 Following injury by low velocity missiles or stab wounds: • Most colonic wounds can be safely closed primarily without the need for a covering stoma (Figure 1210). Use the techniques described in 1233. If resection of the right colon is necessary, an ileo-colic anastomosis is safe for the majority. (see 1244). • Where there are doubts about a repair, cover with a loop ileostomy (Figure 1210) or colostomy (Figure 1211).

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Sigmoid repair plus transverse loop colostomy

Rectal repair plus sigmoid loop colostomy

Fig 1211 Covering a colonic or proximal rectal repair with a loop colostomy.

1244 Casualties included in this category are: Post-operative • High energy- transfer wounds. deterioration or onset of peritonitis • Multiple colo-rectal injuries. are indications for relaparotomy. • Delay before surgery of >6hours. • Prolonged hypovolaemic shock before surgery. • Gross faecal contamination. • Rectal injury, those below the peritoneal reflection mandate faecal diversion. A common mistake Five of the above 6 factors are not dictats when operating on the left colon is mandating that surgery must include diversion failure to mobilise of the faecal stream. They are pointers to greater the splenic flexure risks of leakage from repairs or anastomoses. In the adequately. presence of any one of these factors, particularly injury to the rectum below the peritoneal reflection, faecal diversion is wise. But, each case and the circumstances - clinical and 'military' - surrounding it, must be weighed-up on its merits.

1245 Treatment options are: • Mobilise and exteriorise the damaged segment.

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A

B

C

D

Fig 1212 Loop colostomy: A) A suitable skin incision is made to exteriorise the transverse or sigmoid colon. B) A loop of colon is mobilised and brought through the incision avoiding any tension. C) The loop is held in place using a colostomy bridge. The bowel is opened longitudinally. D) fix the bowel in place using interrupted sutures.

ileostomy or colostomy (NB: not appropriate where there are multiple casualties or when conducting damage control surgery).

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Defect in mobile segments of colon

OR

Resection and Exteriorisation double-barrelled colostomy

Fig 1213 Managing a colonic laceration by exteriorisation or resection and a double-barrelled stoma.

and mucous fistula or double-barrelled colostomy. • Following rectal injury, construct an end colostomy and close off the distal rectum (Hartmann's procedure). • Excluding the rectum, resection and primary anastomosis.

Loop colostomy or exteriorisation 1246 The transverse and sigmoid colons are relatively mobile and can be freed up to form a loop colostomy (Figure 1212) or a damaged segment exteriorised (Figure 1213). • Mobilise a suitable segment of colon, sufficient to reach the anterior abdominal wall without tension. Pass a rubber sling through the mesentery adjacent to the bowel to aid traction. • Make a 10 cm skin incision. This should ideally be midway between the umbilicus and the costal margin, or the umbilicus and anterior superior iliac spine. Divide the deep fascia, muscle and 277 Chapter_12.qxd 28/09/2004 15:55 Page 278 12: Abdominal Injuries

Right hemicolectomy

OR

Ileostomy plus Ileotransverse anastomosis mucous fistula +/- covering loop ileostomy

Fig 1214 Managing an extensive laceration of the right colon by a right hemicolectomy and ileostomy plus mucous fistula, or ileo-transverse anastomosis (+ or - loop ileostomy).

peritoneum in the line of the incision. • Pull the bowel through the defect in the anterior abdominal wall and hold it in place with a colostomy bridge. Suture the bridge to the skin. • Open the bowel longitudinally along one of the taenia coli. Attach the edges to the skin using absorbable sutures on a cutting needle or skin clips. • Attach a suitable stoma bag. Remove the bridge after one week.

Resection 1247 Where there is extensive damage or contamination, resect the affected segment. • Mobilise the involved bowel as in 1242. • It may be sufficient just to resect several 278 centimetres of colon. More usually, the line of Chapter_12.qxd 28/09/2004 15:55 Page 279 12: Abdominal Injuries 12: Abdominal

OR

Endcolostomy Hartmann’s plus mucous procedure fistula

Fig 1215 Management of a rectosigmoid injury: where there is sufficient length, both ends may be mobilised to the surface as an end colostomy plus mucous fistula or, perform a Hartmann's procedure.

bowel division is governed by the remaining blood supply unaffected by injury (Figure 1209). This usually means performing a right hemicolectomy, transverse colectomy, left hemicolectomy or sigmoid colectomy. • Divide the bowel between crushing and non-crushing clamps (1235). • Incise the mesentery and ligate the supplying vessels as close to the bowel as injury allows. Where anastomosis is planned, make sure the bowel ends look healthy and bleed when cut.

Ileo-colic anastomosis 1248 Perform an end-to-end anastomosis as in 1235. If there is discrepancy in size between the terminal ileum and colon, use the technique depicted in Figure 1203 to achieve parity. Alternatively, a side-to-side stapled anastomosis (Figure 1204), or an end-to-side sutured anastomosis, can be employed, (Figure 1214). End-to-side anastomosis: • Mobilise the colon above and below the injury so as to approximate the ends without tension • The colon is closed off by a continuous layer of 3/0 absorbable suture on a round-bodied needle 279 Chapter_12.qxd 28/09/2004 15:55 Page 280 12: Abdominal Injuries

passed over and over a non-crushing bowel clamp. This can be pulled tight once the clamp is released. Then bury the closure with a second layer of sutures. • Milk the adjacent colon to empty it of faeces. Apply a non-crushing bowel clamp. Incise the colon along one of the tenae coli to a distance equal to the diameter of the ileum. Insert stay sutures (Figure 1205). • Anastomose the back wall first using interrupted vertical mattress sutures. The front wall is attached using sero-submucosal sutures. Approximate the mesentery to prevent internal herniation. • Alternatively, perform a stapled anastomosis as in Figure 1204.

End colostomy and mucous fistula or double-barrelled stoma 1249 Following resection, it often quicker and more appropriate to bring the proximal bowel out as an end colostomy and the distal bowel as a mucous fistula (Figure 1215). Using separate incisions may be more convenient and avoids faecal contamination of the distal limb. The disadvantage is the need to perform a further laparotomy to re-establish bowel continuity. The latter can be avoided by bringing out the ends adjacent to each other as a double-barrelled stoma. NB: if one limb is small bowel, construct a spout (Figure 1214). • Select an appropriate point on the anterior abdominal wall to place the end colostomy. This is usually in the left or right iliac fossae, midway between the umbilicus and anterior superior iliac spine. • Lift up and excise a disc of skin (Figure 1216). Make a cruciate incision in the rectus sheath, 280 muscle and peritoneum. 12: Abdominal Injuries 281 E F B C D A Fig 1216A) Excise a disc of skin. B) Construction of an end stoma: end Make a cruciate incision in the abdominal wall. C) Bring the bowel E) through the abdominal wall. D) Fix to skin using interrupted sutures. Close the lateral space. F) Completed stoma. Chapter_12.qxd 28/09/2004 15:55 Page 281 Page 15:55 28/09/2004 Chapter_12.qxd Chapter_12.qxd 28/09/2004 15:55 Page 282 12: Abdominal Injuries

• Bring the bowel end through the wound using Babcock's forceps. Ensure that the bowel is not twisted and that there is no tension. • Attach the colon to the rectus sheath using absorbable sutures on a round-bodied needle. Fixing bowel to skin can be achieved using interrupted, absorbable sutures on a cutting needle or clips. Because large bowel content are unlikely to cause skin irritation, there is no need to form a spout. • To prevent internal herniation, close the lateral space. • Cover with a stoma bag. • The mucous fistula is constructed in a similar manner. Positioning is less crucial. The fistula can usually be covered by a pad. • In a double-barrelled stoma, bring both ends through the same defect. Attach the two limbs to skin and abdominal wall, as well as to each other.

Hartmann's procedure 1250 This is useful for rectal injuries. A defunctioning colostomy to prevent • An end colostomy is brought out as in 1249. faecal soiling is advised for the • The distal end is closed off using two layers initial management of inverting sutures and dropped back into the of extensive wounds of the perineum or pelvis (Figure 1215). Alternatively, close it with buttock which may a stapling gun (e.g., an Autosuture TA 55). involve the anal If the rectal stump is low in the pelvis, it can canal or require be left open. plastic reconstruction. • Where the rectum has been closed off, consider irrigating the stump to reduce soiling of perineal injuries. • If the rectal wound is intraperitoneal, drain the recto-vesical pouch. Where injury has occurred below the peritoneal reflection, drain the 282 presacral space. If a buttock wound is already Chapter_12.qxd 28/09/2004 15:55 Page 283 12: Abdominal Injuries 12: Abdominal

present, this could be used to introduce the drain. Alternatively, the drain is brought out through an incision placed in the median raphe between coccyx and anus, guided by a hand in the abdomen.

Spleen

1251 The friability and vascularity of the spleen There is no place make it susceptible to blows, crush and blast injury. for conservative Treatment is by splenectomy (Figure 1217). treatment of splenic injury in military • Lift the left costal margin and retract the stomach practice. medially and the splenic flexure downwards. A lateral wound extension may improve access. • Gently lift the spleen forward (NB: the already torn capsule is easily further torn). This will reveal the posterior layer of the lienorenal ligament; divided this up to the diaphragm using scissors. The spleen can now be rotated medially and a pack inserted posteriorly. • Divide the short gastric vessels in the gastrosplenic ligament and any omental attachments to the spleen. • The splenic artery and vein are individually ligated close to the hilum; take care not to damage the tail of the pancreas. Drain the subphrenic space.

Post-splenectomy septicaemia 1252 After splenectomy give triple vaccine (S.pneumoniae, N.meningitidis, H.influenzae/B.microti [HIB]) and penicillin prophylaxis to reduce the risk of opportunistic, post-splenectomy infection (OPSI risk 0.1-0.5%; mortality 50%). In endemic areas, provide malarial prophylaxis (2406).

Diaphragm

1253 Injury can occur following blunt or 283

Antibiotics: see Chapter 8 Lienogastric ligament short gastric arteries containing Splenic artery and vein Splenic Spleen Colon Pancreas kidney Left Stomach Division of lienorenal ligament Kidney Colon Lienocolic ligament Stomach D E B C A Fig 1217 control. A) Emergency haemorrhage Splenectomy: B) Division of the lienorenal ligament. C) Lifting the spleen forwards. D) Division of lienogastric ligament. E) Ligation of the splenic vessels at the hilum.

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penetrating trauma. The left side is more commonly affected. Defects allow herniation of abdominal contents into the thoracic cavity. This can result in cardio-respiratory embarrassment or strangulation of the herniated viscera. Small wounds may gradually enlarge causing delayed symptoms (1519). • Repair is using a strong absorbable suture (e.g. No1 PDS) taking care not to injure branches of the phrenic nerve.

Oesophagus This is discussed at 1553

Stomach Introduction

1254 The stomach is injured in 10 to 15% Blood on of all abdominal trauma. Associated injuries to the naso-gastric transverse colon, jejunum, liver, spleen, pancreas aspiration suggests and left kidney are common. Occasionally, a posterior stomach and/or duodenal injury. perforation is the only defect and when missed, is usually fatal. Wounds range from small to large perforations, linear tears to complete transections. The gastric wall has a good blood supply and, if appropriately repaired, will heal well. Because the arteries supplying the stomach are not end-arteries, they can be ligated without fear of necrosis.

Procedures 1255 Major stomach resections are rarely indicated: • Inspect both anterior and posterior surfaces of the stomach. The posterior wall is exposed by making a window in the gastrocolic omentum (Fig 1218). • Tears of the fundus and the body should be excised - remove only devitalised tissue - and closed by an inverting technique. Place stay 285

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Fig 1218 Division of the gastrocolic omentum to expose the anterior surface of the pancreas and the posterior surface of the stomach.

sutures at either end of the defect and close using an all layers continuous absorbable suture (e.g., 3/0 PDS). In order to ensure haemostasis, include the mucosa (Figure 1219). • Gastric repair can be reinforced by serosal sutures or clips. A strand of omentum may be fixed over the defect • Wounds near the pylorus should be closed transversely to avoid narrowing the lumen. Addition of a gastro-jejunostomy is occasionally required if there are concerns regarding gastric outlet obstruction. • Leave a nasogastric tube in place on free drainage with regular aspiration for 3-5 days.

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Fig 1219 Stomach repair: minimal wound excision is required. Insert stay sutures. Close defects and control haemorrhage with all-layers continuous suture. This may be reinforced by a serosal suture layer. Wounds near the pylorus are closed transversely.

Liver Introduction 1256 The liver is damaged in approximately 20 per cent of abdominal wounds, with a ratio of right to left lobe of 5:1. It is particularly vulnerable in right-sided thoraco-abdominal wounds. The hepatic circulation is 1500mls of blood/minute. Consequently, casualties with serious liver trauma frequently die within minutes of injury. By the time those who survive receive medical attention, most liver injuries have stopped bleeding. Major tears can heal without intervention. Liver trauma is broadly divided into three grades of severity: 287 Chapter_12.qxd 28/09/2004 15:55 Page 288 12: Abdominal Injuries

Fig 1220 Liver suture using large, atraumatic needles; re-enforce with an omental patch. Wound drainage.

Injury to the vena cava may initially be 1. Low energy-transfer penetrating injury result tamponaded by an in an oozing, cored-out track, which usually intact posterior heals spontaneously. parietal peritoneum; sudden massive 2. Blunt or penetrating trauma that disrupts haemorrhage from the liver parenchyma causing moderate to this site may catch severe haemorrhage. the unwary surgeon off guard. 3. High energy-transfer penetrating injury producing cavitational effects resulting in extensive disruption of the liver parenchyma with damage to the hepatic veins and inferior vena cava.

Approach Extensive wound 1257 Ideally, have adequate surgical access, excision or resections are not able assistance, adequate light, two working suckers, appropriate in the good venous lines, blood for transfusion and clotting emergency treatment adjuncts - FFP, platelets and rVIIa. A midline incision of liver injury. combined with a lateral extension may be sufficient 288 access (Figure 0402). An inverted 'T', 'Mercedes star' Chapter_12.qxd 28/09/2004 15:55 Page 289 12: Abdominal Injuries 12: Abdominal

Right hepatic vein Division of falciform ligament Division of coronary and triangular ligament behind liver

Left hepatic vein

Middle hepatic vein

Inferior vena cava

Fig 1221 The venous anatomy of the liver. Position of suspensory ligaments - these require division when mobilising the liver.

or roof top incision parallel to both costal margins, gives excellent exposure to the liver and spleen. A right thoraco-abdominal incision (1534) or sternal split (1538) are rarely necessary. Avoid prolonged surgery (0402).

Control of bleeding

1258 At laparotomy, if haemorrhage from tears Placing packs or in the liver has ceased, do not disturb the wound or ribbon gauze in the adherent haematoma. Insert suction drains above liver wound should be avoided. and below the liver. • Minor bleeds can be controlled with diathermy, haemostatic agents or sutures on a large atraumatic needle (Figure 1220). • Most major liver bleeding can be controlled by packing (0408). Effective placement of packs is aided by division of the suspensory ligaments (Figure 1221). These packs are removed at laparotomy 24-72 hours later. In the majority of casualties, haemorrhage will have ceased. • The risks of tight packing include: liver ischaemia, diaphragmatic splinting and compression of the IVC. These considerations are secondary to haemorrhage control. 289

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A

B

Fig 1222 Dividing damaged liver by finger fracture. This enables safe exposure of vessels and biliary canaliculi.

• Control of bleeding from a large defect may be aided by packing it with a vascularised pedicle of omentum held in place with sutures (Figure 1220). • Severe bleeding can be reduced by Pringle's manoeuvre (0408). Each period of occlusion should last no more than 15-30 minutes. Allow 5 minutes for recovery. If Pringle's manoeuvre alone is ineffective, occlude the IVC above and below the liver using vascular clamps, direct compression, tapes or intraluminal balloon tamponade (Figure 0409). By dividing the coronary and right triangular ligaments (Figure 1221), it may be possible to place the upper clamp just below the diaphragm. An easier alternative is to perform a right thoraco-abdominal incision (1538) and clamp the IVC above the diaphragm. 290 Chapter_12.qxd 28/09/2004 15:56 Page 291 12: Abdominal Injuries 12: Abdominal

Liver resection 1259 Once haemorrhage has been controlled, A formal hepatic devitalised liver tissue may be removed using lobectomy in a field surgery setting is fracture techniques: not indicated. • The area to be resected is marked out by incising Glissen's capsule using diathermy. • The parenchyma is pinched between finger and thumb, or gently crushed using an artery forcep (Figure 1222). This will reveal bile ducts and hepatic vessels which can then be safely controlled. Do not excise deep into the liver. • Insert at least two suction drains through the posterior aspect of the right flank.

Complications of liver trauma 1260 These include: • Bleeding: A subcapsular or intrahepatic haematoma usually resolves spontaneously. Secondary haemorrhage typically occurs 4-8 days after injury and is caused by infection or an increased bleeding tendency. There may be delayed rupture leading to traumatic haemobilia. • Suppuration. Contributory factors include failure to excise necrotic or devitalised liver tissue, strangulation by injudicious use of deep sutures, inadequate drainage and contamination by bowel contents. Abscesses can be subphrenic, subhepatic or intrahepatic; they are often multiple. Treatment is by drainage. This can be open, or percutaneous under ultrasound guidance with antibiotic cover. • Biliary fistula. Bile is frequently seen in the drain after liver surgery; this usually resolves. Collections can be drained percutaneously under ultrasound guidance. Development of bile peritonitis necessitates laparotomy. A persistent 291

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Fig 1223 "Kocherising" the duodenum to expose its posterior surface and the posterior surface of the head of the pancreas.

biliary fistula is often managed by endoscopic retrograde cholangio-pancreatography (ERCP) and interventional radiology.

Duodenum Introduction 1261 Wounds of the duodenum, biliary tree and Retroperitoneal pancreas are rarely encountered on the battlefield injuries of the duodenum are often due to the high mortality from combination wounds missed and to organs in close proximity, or coincidental trauma frequently fatal. to the aorta or IVC. Operative findings suggesting duodenal injury include: • Adjacent haematoma. • Retroperitoneal gas. • Tissue discoloration due to bile leakage. 292 Chapter_12.qxd 28/09/2004 15:56 Page 293 12: Abdominal Injuries 12: Abdominal

Omental patch

Fig 1224 Simple duodenal lacerations can be closed transversely. Cover with an omental patch and decompress. Options for decompression are a nasoduodenal tube or a duodenostomy tube proximal to the repair.

Following blunt injury, a water soluble contrast meal may confirm a duodenal leak; (use CT if available). Problems with healing, especially following injuries of the second part, are caused by tension at the site of repair. This is due to the large, combined output of the stomach, pancreas and biliary tree. Duodenal wall haematomas usually resolve spontaneously but can perforate. When causing obstruction, they can be managed by incision of the serosa and evacuation of the haematoma, or by nasogastric aspiration. 293 Chapter_12.qxd 28/09/2004 15:56 Page 294 12: Abdominal Injuries

Fig 1225 The duodenal repair may be protected by temporarily closing off the pylorus from within using an absorbable purse-string suture plus either, continued nasogastric aspiration or, a gastro-jejunostomy.

Approach 1262 Where indicated, inspect the anterior and posterior surfaces of the four parts of the duodenum. • Mobilise the hepatic flexure of the colon and free sufficient greater omentum from the transverse colon.

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of the pancreas can be visualised by carrying out In the severely ill casualty with a Kocher's manoeuvre, (Figure 1223). duodenal injury, you • Dissection is continued medially to expose the may be forced to do no more than pack inferior vena cava and aorta. the area at the initial operation. If you • The third and fourth parts of the duodenum are decide that exposed by mobilisation of the ligament of Treitz. exploration of a retroperitoneal Simple wounds haematoma is essential, be 1263 Minor wounds can be treated by minimal prepared to deal with wound excision and transverse closure, providing this major bleeding. does not significantly narrow the lumen (Figure 1224) • Use one or two layers of absorbable sutures (e.g., 3/0 PDS). This may be reinforced by an omental patch. • After repair, the duodenum must be decompressed with a naso-duodenal tube, or balloon catheter inserted as a tube duodenostomy. Where a tube duodenostomy is being used to protect a repair, it is inserted through a separate proximal incision (Figure 1224). The site of the anastomosis and the retro-duodenal area should be drained using suction drains. • Short segment loss affecting the 1st, 3rd and 4th parts of the duodenum can be treated by excision and re-anastomosis, providing this can be achieved without tension. • Healing of a duodenal repair may be aided by temporarily closing off the pylorus. This is performing via a short gastrotomy. A continuous absorbable suture is inserted around the pylorus. This is combined with a gastro-jejunostomy or regular nasogastric aspiration, (Figure 1225). In approximately 90% of cases, the pylorus reopens within three week, by which time the repair should have healed. 295 Chapter_12.qxd 28/09/2004 15:56 Page 296 12: Abdominal Injuries

Fig 1226 A jejunal serosal patch used to repair a duodenal laceration.

Major injury A duodenostomy is 1264 Damage control surgery for significant a useful technique duodenal injury is to: in inexperienced hands, particularly • Insert one or more wide-bore, balloon catheters where surgery is difficult or delayed. It through the defect so as to form a 'controlled will protect a repair fistula' (Figure 0411). considered at risk of dehiscence. • Each balloon is inflated with 3-5mls of water and the catheter left on free drainage. • Where possible, the defect in the wall is closed around the catheter using absorbable sutures. 296 Fix a strand of omentum over the duodenum. Chapter_12.qxd 28/09/2004 15:56 Page 297 12: Abdominal Injuries 12: Abdominal

Fig 1227 Other methods for repair or drainage of a duodenal laceration.

• Adjuncts to the above include: nasogastric aspiration, parentral feeding and pharmaceutical reduction of gastric secretion (e.g., proton pump inhibitors e.g., octreotide. • After 14 days, a track will have formed and the catheter can be gradually withdrawn.

Where repair of major defects is indicated, the traditional approach is to construct a jejunal serosal patch (Figure 1226). Place the sutures well clear of the edges of the defect. Though simple, this technique may leak. Other options are illustrated in Figure 1227. 297 Chapter_12.qxd 28/09/2004 15:56 Page 298 12: Abdominal Injuries Gallbladder and biliary tree Introduction 1265 Tears in the gallbladder are common after blast injury. Injuries to the bile ducts are associated with major vascular injuries and are often fatal. Injuries to the gallbladder are treated by cholecystectomy or insertion of a cholecystostomy tube. Injuries to the duct system are dealt with by direct repair around a T-tube using absorbable sutures (Figure 0410). Approach 1266 Exposure is by upward retraction on the liver, medial retraction on the duodenum and downward traction on the hepatic flexure of the colon. Exploration of the distal common bile duct requires incision of the overlying peritoneum and "Kocherisation" of the duodenum (1262) in order to inspect the pancreatic portion.

Cholecystectomy 1267 Identify and ligate the cystic artery in Calot's Triangle. Free up the cystic duct and double ligate or transfix it with absorbable ties or sutures. Free the gallbladder from the liver bed. Following all forms of biliary surgery for trauma, insert an adjacent suction drain.

Cholecystostomy 1268 A quick and easier alternative to cholecystectomy is to resect the damaged portion and close the remaining gallbladder around a cholecystostomy tube (Figure 0410). Introduce a large rubber balloon catheter through the adjacent anterior abdominal wall into the defect in the gallbladder. Inject 5mls of fluid in the balloon. Close the wall around the tube using an absorbable, purse string suture. Suture the catheter to the 298 abdominal wall. Chapter_12.qxd 28/09/2004 15:56 Page 299 12: Abdominal Injuries 12: Abdominal

Line of excision

Fig 1228 Mobilisation of the distal pancreas and spleen prior to distal pancreatectomy. Approximately 10- 14 days after cholecystostomy or insertion of a T-tube, a track will have formed. Inject contrast into the tube and X-ray in order to check biliary flow. If satisfactory, remove the tube. Any leakage of bile will dry up.

Pancreas Introduction 1269 Pancreatic trauma is often associated with major vascular damage, diagnostic delay particularly, after blunt injury and a fatal outcome. The only reliable method of excluding a suspected pancreatic duct injury is to inject contrast through the Sphincter of Oddi via an intra-operative duodenostomy or, preoperative ERCP. Delayed pancreatic surgery is often unsuccessful.

Approach 1270 Anterior and posterior surfaces of the head of the pancreas are exposed as for duodenal examination (1262). The body and tail of the pancreas are inspected through a window made in the gastro-colic omentum (Figure 1218). To inspect the posterior aspect, mobilise the spleen and the pancreas to the right (Figure 1228). 299 Chapter_12.qxd 28/09/2004 15:56 Page 300 12: Abdominal Injuries

Fig 1229 The pancreas can be swung forward to ligate the splenic vein. Note exposure of the coelic axis, portal vein and inferior mesenteric vein.

Major injury 1271 Damage control surgery for haemorrhage is to pack the wound. Insert two or more drains. Do not explore a retroperitoneal haematoma unless it is clearly expanding (1274). Where there is extensive injury to the head of the pancreas and duodenum, drain as in Figure 0411. Transection through the pancreatic neck or tail in a stable casualty may be treated by resection of the distal pancreatic remnant.

• Mobilise as in Figure 1228. Because of the proximity of the splenic vessels, pancreatic resection is usually accompanied by splenectomy (1251). • Swing the mobilised pancreas and spleen forwards to release any posterior attachments (Figure 1229). • Divide the neck of the pancreas over the aorta 300 (Figure 1230). Oversew the proximal end of the Chapter_12.qxd 28/09/2004 15:56 Page 301 12: Abdominal Injuries 12: Abdominal

Fig 1230 Distal pancreatectomy: the pancreatic duct is transfixed and the fish-tailed pancreas approximated.

divided pancreatic duct. Close the thin pancreatic capsule over the remaining tissues using interrupted sutures (e.g., 3/0 Prolene) and cover with omentum. • Resection of the head of the pancreas and reconstruction should only be contemplated at Role 4 (Figure 1231).

Minor injury 1272 Where there is minimal contusion or a laceration not involving a major duct, treat by suction drainage. Where a fresh defect in the pancreatic duct can be identified: • Effect repair using interrupted, monofilament non-absorbable sutures (e.g., 5/0 Prolene). • Close pancreatic tissue and capsule over the injury using lightly tied sutures (e.g., 3/0 Prolene) and cover with a pedicle of omentum. 301 Chapter_12.qxd 28/09/2004 15:56 Page 302 12: Abdominal Injuries

Fig 1231 A method of reconstruction after pancreatico-duodenectomy.

• Place suction drains anterior and posterior to the pancreas.

Complications 1273 These include: • Haemorrhage: occurs as a result of infection or erosion of adjacent blood vessels secondary to leakage of pancreatic juice. This requires an 302 emergency laparotomy. Chapter_12.qxd 28/09/2004 15:56 Page 303 12: Abdominal Injuries 12: Abdominal

• Pancreatic fistula and pseudocyst formation: Always examine the pancreas in cases of loss of pancreatic juice via the drain is common upper abdominal and rarely serious. Drainage should be into a trauma. bag to prevent skin damage. Small leaks resolve on conservative treatment. Damage to a major duct may require a pancreatectomy, or Roux-en-Y diversion. Investigate by ERCP. Pseudocysts can be drained percutaneously under ultrasound control. • Abscess formation: usually due to a missed pancreatic injury or leakage of pancreatic juice. Treatment is by drainage. • Pancreatitis: usually responds to conservative treatment. • Protracted recovery: Maintain nutrition by parenteral or enteral feeding.

Urological Trauma

This is discussed in Chapter 14

Management of retroperitoneal haemorrhage 1274 Most retroperitoneal haematomas are managed by packing. Before exploring you must If a retroperitoneal obtain proximal and distal control of potentially haematoma is not expanding, other involved vessels. The retroperitoneum can be divided abdominal injuries into four zones: take precedence. • Central: haematomas should be explored to exclude injuries to the aorta, IVC, pancreas and duodenum. • Left and right lateral: haematomas can be left undisturbed unless they are expanding or the casualty remains hypotensive and, in the absence of other injuries, unstable. Routine exploration of lateral haematomas results in an unnecessarily high nephrectomy rate. 303

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Major vascular • Pelvis: if the haematoma is not expanding, leave damage is more common after it alone. If it is rapidly enlarging, the pelvic cavity penetrating than should be packed and, if not done already, blunt trauma, but external fixation or other methods of compression, when it does occur applied to the pelvis. In the right setting, perform it tends to be complex and often arteriography with a view to embolisation (0411). fatal. Shearing and This will only control bleeding that is arterial in traction forces can origin. Surgical exploration of pelvic haematomas cause avulsion, is rarely helpful and often leads to uncontrollable intimal tears, thrombosis and blood loss. distal ischaemia. Presentation may Retroperitoneal exposure be delayed. 1275 The two main manoeuvres for the exposure of the major vessels in the abdomen are: 1. Medial visceral rotation from the right • The avascular peritoneum lateral to the caecum, ascending colon and hepatic flexure is incised and the bowel and mesentery mobilised towards the midline (Figure 1208). • Stay in front of the right kidney and ureter. • The duodenum and head of pancreas are mobilised by Kocher's manoeuvre to expose the renal vessels, infrahepatic inferior vena cava and aorta (Figure 1223). 2. Medial visceral rotation from the left • The peritoneum lateral to the sigmoid colon, descending colon and splenic flexure is incised and the bowel and mesentery mobilised towards the midline (Figure 1208). • The spleen and tail of pancreas can be mobilised with the colon (Figure 1228). • Continue dissection until the full length of the abdominal aorta is exposed, as well as the coeliac axis, superior mesenteric artery, left renal artery and inferior mesenteric artery 304 (Figure 1229). Chapter_12.qxd 28/09/2004 15:56 Page 305 12: Abdominal Injuries 12: Abdominal

Individual exposure of major vessels and their management 1276 Aorta • In the severely hypotensive casualty, the aorta may be clamped via a thoracotomy or laparotomy incision. NB: this unlikely to be applicable under field conditions.

• Perform a left anterior thoracotomy through the Wounds of the aorta 5th intercostal space (1534). This may be and intra-abdominal facilitated by deflating the left lung. Free vena cava are usually fatal. Those attachments of the inferior surface of the lung that survive to reach and retract anteriorly and superiorly. Incise the a surgical centre mediastinal pleura over the thoracic aorta and will require urgent separate the latter from the oesophagus. surgery. Occlude the aorta with a vascular clamp placed just above the crura (Figure 0405). • The supra-coeliac aorta can be clamped by making a window in the lesser omentum. Lift the oesophagus and lesser curve of the stomach forward and identify the aorta at the diaphragmatic hiatus (Figure 0406). Clamp the aorta above the coeliac artery (NB: avoid the pancreas). An alternative is to compress the aorta at the same site. • The infrarenal aorta is exposed by retracting small bowel to the casualty's right and descending colon to the left (Figure 1232). Incise the peritoneum at the duodenojejunal flexure (ligament of Treitz) and mobilise it to the right. The incision is continued down as far as the common iliac arteries and the posterior peritoneum reflected off the aorta. Exposure can be improved by dividing the left renal vein as it crosses the aorta - this is unlikely to cause complications in the young and fit.

1277 Inferior vena cava (IVC) • The infrahepatic IVC is exposed by medial 305 Chapter_12.qxd 28/09/2004 15:56 Page 306 12: Abdominal Injuries

Retroperitoneal incision

Pancreas Duodendum

Left renal vein

IVC

Aorta

Retracted small bowel

Inferior mesentric artery

Fig 1232 Incising the posterior peritoneum to expose the infrarenal aorta and vena cava. The colon is retracted to the left and the small bowel to the right.

Opening the chest displacement of the viscera from the right helps to prevent air (1275). Haemorrhage is controlled by local emboli by equalising pressure (1029) or use of balloon catheters intrathoracic and (Figure 0409), in preference to clamping. Tears abdominal pressures. in the IVC are closed with continuous 5/0 Prolene. Posterior lacerations are best repaired transcavally by enlarging the defect in the 306 Chapter_12.qxd 28/09/2004 15:56 Page 307 12: Abdominal Injuries 12: Abdominal

anterior wall, rather than attempting to rotate Compression of the IVC while trying to the vessel. In extremis, the infrarenal IVC can effect repair may be ligated; this will result in varying degrees of cause cardiac arrest. leg oedema. Exposure of the defect in the IVC • Injuries of the suprarenal IVC are best treated may result in air by reconstruction with an externally supported embolism. PTFE graft and systemic anticoagulation. • Control of bleeding from the liver and retrohepatic IVC is discussed in 0408. Subsequent repair of the cava may necessitate wound extension into a right anterior thoracotomy or median sternotomy. Occasionally, it may be possible to control the defect using a Satinsky clamp applied to the side of the vessel, thereby only partially occluding the IVC. At Role 4, use of an atria-caval shunt will preserve venous return whilst the retrohepatic IVC is repaired.

1278 Coelic axis and its branches Do not attempt • The coelic axis is exposed by medial visceral complex interposition rotation from the left (1275). Because it is grafts when repairing difficult to repair, ligate the damage vessel injuries of the coeliac, SMA, IMA or proximal to the main branches; if the superior their branches. mesenteric artery is intact, the risk of visceral ischaemia is approximately 10%. • The left gastric artery can be ligated with impunity. • The splenic artery is best tied rather than repaired. Perform a splenectomy (1251). • The origin of the common hepatic artery can To prevent be exposed by medial visceral rotation from the gallbladder necrosis left (1275). Alternatively, make a window in the after ligation of the lesser omentum adjacent to the distal lesser hepatic or right curve of the stomach and retract the duodenum hepatic arteries, perform a inferiorly. The hepatic artery lies in the free cholecystectomy. edge of the lesser omentum medial to the common bile duct and anterior to the portal vein 307

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(NB: identify and avoid these structures). The common hepatic artery can be ligated safely proximal to the gastroduodenal artery; occlusion distal to the gastroduodenal artery infrequently causes hepatic necrosis.

1279 Superior mesenteric artery (SMA)

Rarely it may be • The origin of the SMA is exposed by medial necessary to divide visceral rotation from the left (1275). More the neck of the distally, the artery can be found in the base pancreas to improve of the small bowel mesentery. exposure to the SMA. • The proximal SMA must be repaired or bypassed using saphenous vein or a synthetic graft (NB: avoid graft kinking). Administer 5,000 unit of i.v. heparin systemically prior to clamping the artery. Where there are Check inflow and backflow; flush before doubts concerning bowel viability after completing the final anastomosis (1024). vascular repair, • The distal SMA may be ligated; this usually perform a second look laparotomy necessitates resection of a segment of 24-48 hours later. devascularised small bowel (1235).

1280 Portal vein (PV) • The PV is formed by the confluence of the splenic and superior mesenteric veins behind the pancreas. • The origin may be exposed by Kocher's manoeuvre (1262) from the right, or medial visceral rotation from the left (1275). It may be necessary to divide the neck of the pancreas to gain adequate access (1271). • The PV in the free edge of the lesser omentum is mobilised by dividing the peritoneum and retracting the common bile duct to the left. • Injuries to the PV are closed with 5/0 continuous Prolene. • In extremis, the PV can be ligated. 308 Chapter_12.qxd 28/09/2004 15:56 Page 309 12: Abdominal Injuries 12: Abdominal

1281 Inferior mesenteric artery (IMA) • The origin of the IMA can be identified when exposing the infrarenal aorta (1276). • Unless there is damage to the SMA and internal iliac arteries, it can be safely ligated (1% risk of colonic ischaemia). NB: check colonic viability prior to abdominal closure.

1282 Iliac arteries • Exposure of the common iliac arteries (CIAs) and external iliac arteries (EIAs) is through a standard midline laparotomy incision. On the right, mobilisation of the caecum may be necessary, on the left, freeing-up of the sigmoid colon. Identify the ureters as they cross the iliac bifurcation on both sides. Passing slings around the iliac arteries may damage the adherent iliac veins. It is safer to control the artery by pinching, applying a Fogarty clamp or use of occlusive catheters passed upwards from the groin. • The distal external iliac artery is difficult to approach from the abdomen and may necessitate separate groin incisions (1045). • Ligating the CIAs and EIAs risks lower limb ischaemia (Figure 0412); they should be repaired or replaced with a synthetic interposition graft (1031). If close to the aortic bifurcation, this may require a trouser graft. Where a unilateral injury cannot satisfactorily be repaired, ligate the vessel and perform an extra-anatomical bypass (Figure 1012). • Injuries to the internal iliac arteries are managed by packing (1274). Exposure of the artery is difficult and because of pelvic cross-filling, ligation of one artery is often not effective at controlling haemorrhage.

309

Pelvic Fracture: see Chapter 13 Chapter_12.qxd 28/09/2004 15:56 Page 310 12: Abdominal Injuries Complications of abdominal surgery Conditions that may require re-operation include: 1283 Wound dehiscence: contributory factors include infection, poor nutrition, prolonged abdominal distension and inadequate wound closure techniques.

1284 Missed intra-abdominal injury: commonly overlooked injuries are those involving retroperitoneal structures, fixed portions of the colon and the viscera bordering the lesser sac.

1285 Intestinal obstruction: a prolonged ileus is common after abdominal trauma or major surgery. It usually resolves with a regimen of "drip and suck" and correction of predisposing factors (e.g., electrolyte imbalance). Mechanical obstruction is due to the development of adhesions or abscess formation between loops of bowel. Early operation may correct the obstruction more successfully than conservative treatment.

1286 Secondary haemorrhage: is due to infection causing erosion of a blood vessel. Haemorrhage is generally profuse necessitating emergency surgery. This is particularly likely to happen when a haematoma, resulting from an injury to a retroperitoneal vessel, is not explored at the original operation.

1287 Intra-abdominal abscesses: classical features are a toxic casualty with a swinging pyrexia. The usual locations are the four abdominal quadrants plus the pelvis. It may be possible to drain an abscess under ultrasound control.

1288 Anastomotic dehiscence: classically occurs 5-10 days after bowel surgery. Providing there is no distal obstruction and the casualty remains well, 90% heal on conservative treatment. Management 310

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includes radiology to define the fistula (fistulogram, small bowel meal/enema), enteral or parenteral nutrition and skin protection. Surgery to close the fistula is occasionally required at Role 4.

1289 Stomal problems: include necrosis, retraction or stenosis. The commonest causes are inadequate mobilisation or poor blood supply. Though a local procedure may be possible, major stomal problems usually require revision at a second laparotomy.

1290 Abdominal compartment syndrome (ACS): a persistent increase in abdominal pressure can compromise intra-abdominal organs, the lungs and abdominal wall. Features include: • Reduced glomerular filtration rate leading to oliguria and renal failure. • Diminished blood flow to the splanchnic circulation allowing increased absorption of toxins, translocation of gut bacteria and septicaemia. • Hypoperfusion of the abdominal wall increasing the risk of wound infection and breakdown. • IVC compression leading to reduced cardiac output and heart failure. • Decreased pulmonary compliance leading to an increase in peak inspiratory pressure (e.g., >40cm water), a deterioration in the PaO2/FiO2 ratio and respiratory failure. The syndrome is usually suspected when the casualty develops oliguria and becomes increasingly difficult to ventilate. It is typically seen in casualties who have suffered: • Severe trauma requiring large volume blood transfusion. 311

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• Tight abdominal closure over packs or dilated bowel. • Prolonged hypotension. • Burns >20%. The diagnosis is confirmed by bladder pressure monitoring at Role 4. This is believed to accurately reflect intra-abdominal pressure. A value >25mmHg for four hours is diagnostic. Initial treatment may include • Diuretics, increased sedation and nasogastric tube aspiration. • Failure to respond to these measures over the next two hours is an indication for urgent laparotomy, decompression and partial abdominal closure (0412). • Where ACS is considered a likely complication, it may be preferable to leave the wound open after the initial operation.

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Pelvic Injury

Introduction

1301 The mortality from pelvic fractures is high Massive force is due to exsanguinating retroperitoneal haemorrhage required to disrupt or associated injuries. Surgical intervention is often the pelvic ring. required to arrest haemorrhage after major injury. Managing such casualties in an austere environment is challenging.

Pathoanatomy

1302 The pelvis is a complete ring of three bones (two innominate and the sacrum) and three joints (two sacroiliac and the symphysis pubis). These joints rely completely on ligamentous reinforcement for their integrity. The broad anterior and posterior sacroiliac ligaments are the strongest in the body. The internal iliac and superior gluteal arteries are bound to the bones of the posterior pelvis. All pelvic viscera lie upon a thin-walled, venous plexus that drains directly into the internal iliac veins or portal venous systems. Following sacroiliac joint damage, there may be disruption of these vessels and damage to the sacral nerves. Typically, there is retroperitoneal haemorrhage from the major vessels, bleeding from exposed raw bone surfaces and from the thin-walled venous plexi. The majority of pelvic fractures are closed. Open pelvic fractures represent the most severe form of this injury and half of those affected will die.

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The direction 1303 Major pelvic fracture is usually the result and magnitude of of blunt trauma e.g., vehicular accidents, falls and the force applied to crushing. Penetrating injury may also occur. High the pelvis, will define the fracture type. energy-transfer wounds involving the bony pelvis, blood vessels and viscera, carry a high mortality. There are three main fracture patterns.

Lateral compression fracture (LC) 1304 This "implosion" injury is the commonest pelvic fracture type (66-75%) and is typically seen after side impact vehicular accidents. Major vascular disruption is uncommon and, if present, is usually due to vessel penetration by a bone fragment. Less than 10% of casualties with this fracture pattern are hypotensive. Morbidity and mortality are usually due to associated abdominal, thoracic or head injury on the side of impact. Application of a pelvic external fixator is rarely necessary. There are three sub-types:

• Lateral compression type 1 (LC1): moderate direct lateral force to the posterior pelvis causes transversely orientated ramus and sacral compression fractures. Distortion of the oval sacral foramina is seen on AP pelvic radiography. This is a stable fracture. • Lateral compression type 2 (LC2): moderate direct lateral force to the anterior pelvis causes transversely orientated ramus and cresentric iliac wing fractures (Figure 1301 A). Asymmetry is seen on the pelvic radiograph. • Lateral compression type 3 (LC3): major compression force is applied to both halves of the pelvis. Firstly, the ipsilateral iliac wing is rotated inwards and either fractures or disrupts the posterior sacroiliac ligaments. As the force continues across the pelvis, the contralateral 314 iliac wing is rotated outwards. The result is

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sometimes referred to as a "windswept pelvis". LC3 injuries occur after vehicular rollover or severe crushing and are often accompanied by major degloving of pelvic skin.

Anteroposterior compression (APC) fracture 1305 APC fractures are due to major forces applied to either the front or back of the pelvic ring. Direct frontal This injury is characterised by pubic symphysis accidents of any diastasis and/or vertical pubic rami fracture. In type have the contrast to vertical shear injury (1306), there is no highest mortality. marked upward shift of the pelvis. APC fractures often occur in motorcyclists after frontal, high-speed APC2 and APC3 impact. The anterior pelvis is forced against the fuel pelvic fractures are tank and splayed open. There are three sub-types: potentially fatal. "Closing the book" • Anteroposterior compression type 1 (APC1): by emergency splintage and This is typically a sporting injury. There is minor application of an separation of the symphysis pubis (<2.5cm), with external fixator, intact posterior structures and no fractures. may be life saving. This is a stable injury. • Anteroposterior compression type 2 (APC2, "open book” injury). This is the most frequent sub-type. The anterior sacroiliac ligaments are disrupted, whilst the posterior ligament complex Ejectees are is undamaged. This broad posterior ligament has twenty-five times been likened to the binding of a book. The book more likely to be seriously injured opens at the front but is held together at the when compared back (Figure 1301 B). Symphyseal separation to belted, restrained is >2.5 cm in the unreduced state. Vertical vehicle occupants. fractures of the rami may be seen in this and the Following a fatal RTA, expect APC3 subtype. A radiological clue to an APC2 survivors to have injury is the presence of an avulsion fracture of serious injuries. the transverse process of L5 secondary to traction on the iliolumbar ligament. The sacrotuberous and sacrospinous ligaments are also torn. There is likely to be associated pelvic visceral and soft tissue damage. One third of these casualties will be hypotensive on arrival at a field surgical facility. 315 Chapter_13.qxd 28/09/2004 15:56 Page 316 13: Pelvic Injury

.

A

B

C

Fig 1301 A. Lateral compression type 2 injury: fracture of the transverse pubic rami plus either, a sacral compression or, a cresentic iliac wing fracture. The pelvic ligaments are intact. B. Anteroposterior compression type 2 injury: wide symphyseal diastasis and disruption of the anterior and posterior sacroiliac ligaments. The sacrotuberous and sacroiliac ligaments are also torn. 316 C. Vertical shear injury. Chapter_13.qxd 28/09/2004 15:56 Page 317 13: Pelvic Injury

• Anteroposterior compression type 3 (APC3): "Read the injury". Check all casualties This massive injury consists of a complete with pelvic fractures separation of one hemipelvis from the rest of the for associated pelvic ring and, by definition, the rest of the body injuries: femoral ("complete traumatic hemipelvectomy"). shaft fracture, closed head injury, The anterior and posterior sacroiliac ligaments haemothorax, liver or are torn. APC3 injuries are associated with splenic trauma, severe pelvic visceral and vascular disruption. urological and Two-thirds of these casualties will be rectal damage. hypotensive on admission with an average GCS of 9. There is little or no vascular tamponade because the complete ligamentous disruption permits unrestricted expansion of the haematoma into the retroperitoneal space and pelvis. On average, 15 units of blood are required during initial resuscitation and surgery.

Vertical shear injury (VS) 1306 VS injury typically results from a fall of >5 metres. The key feature is upward and posterior displacement of the hemipelvis (Figure 1301C). The posterior injury is usually through the sacroiliac joint, but can be via a sacral or iliac wing fracture. Anteriorly, there may be symphyseal diastasis, or a vertical fracture of the rami. The diagnosis should be suspected from the history or, the finding of unequal leg length in the absence of an obvious femoral shaft fracture or hip dislocation. Hypotension on admission is present in approximately 12% of casualties.

Minor Pelvic Fractures

1307 Isolated fractures of the iliac wing and single fractures through a pubic or ischial ramus, do occur. As the pelvic ring remains intact, these are of limited clinical importance. Management consists of 2-3 days bed rest, analgesia and progressive mobilisation. Isolated low energy penetrating fragment injuries of the iliac wing, in the 317

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absence of other injury, require wound excision (0503) and minor nibbling of the bone edges.

Acetabular fractures 1308 Fractures of the acetabulum are caused by forces applied through the femur and femoral head following falls or vehicular accidents They are uncommon and not life threatening. Often, the femoral head dislocates posteriorly and can injure the sciatic nerve (0966). Reduce as in 0967 and apply traction. Open reduction and internal fixation of the acetabulum may be necessary at Role 4.

Soft tissue trauma 1309 All fracture types may be open or associated with soft tissue trauma. Deep buttock wounds are at risk of gas (Clostridial) gangrene (0808). Injuries involving the perineum - especially of the "splitting type" - which run from the lower anterior abdominal wall, through the perineum, to the posterior surface of the sacrum, must be assumed to involve the rectum.

Assessment and Management

Role 1 and 2 1310 Suspect a pelvic fracture in all those who have suffered major blunt trauma. Knowing the history (e.g., fall >5m = vertical shear injury?) and "reading the wreckage" (e.g., inwards deformation at door level = lateral compression injury?), provides a clue as to the likely pattern of injuries.

1311 Assess and resuscitate according to BATLS principles. Casualties with APC and some VS injuries, are often profoundly hypotensive.

318

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1312 Look If the casualty • Deformation of the pelvis, unequal leg length has an injury and excessive external rotation of one or above and below the pelvis, assume both feet. that the pelvis is also affected . • Open wounds: perineal splitting wounds point to an "open book" injury. Following missile injury, look for entry and exit wounds. • Soft tissue injury: shearing skin wounds suggest vehicular roll-over or crush injury. Examine for bruising and tenderness of the groin, perineum, pubic area and posteriorly over the sacroiliac joints. Look for tyre marks on the skin or clothing.

• Scrotal haematoma and blood at the external A retroperitoneal urethral meatus are the classical signs of haematoma may urethral disruption but, may not always cause paralytic ileus. accompany this injury (1423). • In the secondary survey, test for altered leg sensation and/or foot drop (2115). If either is present, it suggests sciatic nerve compression or damage. • Abdominal distension may be due to intra-abdominal injury.

1313 Feel • Pubic diastasis. The pelvis may be examined by taking hold of the iliac blades behind the anterior superior iliac spines. A single attempt is made to pull the blades apart followed by squeezing them together (Figure 1302). This manoeuvre should be performed carefully, slowly and once only (if at all), as a life saving clot can be dislodged by repetition. Movement, crepitus or severe pain, indicate a pelvic fracture. It may be possible to feel a gap at the pubic symphysis. • Following a vertical shear injury, abnormal cephalad/caudad movement of the disrupted 319 Chapter_13.qxd 28/09/2004 15:56 Page 320 13: Pelvic Injury

Fig 1302 Testing for an anteroposterior compression “open book” pelvic fracture.

pelvis can be tested for by performing a single, gentle push-pull manoeuvre of the limb on the affected side. Get an assistant to steady the pelvis. • When circumstances allow, perform a rectal and/or vaginal examination. Look for features suggestive of a rupture of the membranous urethra (1423). Blood in the vagina or rectum is usually due to penetration by a fracture fragment and typically occurs following LC injuries (NB: this is by definition, an open pelvic fracture).

1314 Investigations • Perform standard primary survey radiographs (C-spine, chest and pelvis). • FAST (1213). 320

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1315 Initial treatment Do not attempt to • Apply a pressure dressing to open wounds. manipulate and splint broken legs together • Immobilise "open book" pelvic fractures using - check for other limb a strap, belt or sheet wrapped firmly around the injuries first! pelvis at the level of the greater trochanters (Figure 1303). The legs should be tied together in internal rotation with a series of bandages (feet, calves and thighs). Prevent pressure sores by placing padding between knees and ankles (Figure 0322). Alternatively, use a well-moulded vacuum splint. • Following a VS injury, splint the affected leg to its neighbour in as near to the correct length as possible. Immobilise the pelvis as above. • Analgesia (Figure 0701). • Give antibiotics for open or potentially contaminated wounds (0816 and 0817). • Urgently transfer to a Role 3 or 4 facility.

Role 3 and 4

1316 Investigations The use of Military Anti-Shock Trousers/ Consider: Pneumatic • Ultrasound scan, CT (1214) or supra-umbilical Anti-Shock Garments is no longer DPL (1212) looking for bleeding. recommended. Their removal • Proctoscopy, sigmoidoscopy and vaginal during examination speculum examination. can result in fatal hypovolaemic shock. • Ascending urethrogram, cystogram or IVU (1407).

1317 Treatment • Most LC1 and LC2 injuries are managed by 2-3 days of bed rest and analgesia, followed by mobilisation, starting with partial weight bearing on crutches. LC3 and some LC2 injuries need specialist reconstruction at Role 4. 321

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Fig 1303 Emergency immobilisation of an anteroposterior compression “open book” pelvic fracture with a broad Velcro™ strap applied firmly over the greater trochanters. • APC2 and APC3 injuries require emergency

Infraumbilical DPL application of a pelvic external fixator (1320), may produce a false an effective pelvic binder or C-clamp. "Closing positive result from a the book" will tamponade retroperitoneal anteriorly tracking bleeding and may save the casualty's life. retroperitoneal haematoma - use a This should be achieved before laparotomy. supraumbilical An external fixator applied to the pelvis can be approach. arranged such that it will not interfere with a full, mid-line laparotomy. Binders are now available that will also allow laparotomy after they have been applied. • An external fixator can be used as definitive treatment, but often loosens. At Role 4, consider internal fixation. • Where transfer is not possible, bed-rest and traction may be the only safe alternative to surgery. • VS injuries are reduced by applying 10kg of tibial traction to the affected leg (0935) for 6 weeks. The traction is adjusted to bring the hemipelvis into the correct position. • Therapeutic options if bleeding continues, are summarised in Figure 1304. At Role 4, consider angiographic embolisation. • Approximately 85% of casualties who have 322 sustained a transpelvic gunshot wound, require laparotomy.

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Hypotensive casualty

Increased pelvic volume No increase in volume APC/VS LC

DPL/USS DPL/USS -ve +ve -ve +ve

both External fixation Laparotomy Injury elsewhere?

Consider Angiography and packing of open pelvic wounds.

Fig 1304 Management of a hypotensive casualty with a fractured pelvis. (APC - anteroposterior compression; VS - vertical shear; LC - lateral compression; DPL - diagnostic peritoneal lavage; USS - ultrasound scan).

• Deep, soft tissue and open fractures, require wound excision (0503). • Following major perineal injury, perform a colostomy and wash out the distal segment (1249). Faecal matter must not be allowed to enter the distal loop and contaminate the wound. The colostomy may be closed once the perineal injury has healed. • Prophylaxis against deep vein thrombosis (DVT) and pulmonary embolism (PE) - see 0980.

Complications of Pelvic Injury

1318 Early • Continued bleeding, rebleeding or haematoma. • Paralytic ileus. • Retention of urine. • Infection and abscess formation. • DVT/PE (0979).

• Fat embolism (0982). 323

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Fig 1305 Insertion of three pins in the ilium

Late • Abnormal gait. • Osteoarthritis.

Application of a Pelvic External Fixator

1319 Technique: 1. Use two Centrafix™ or Hoffmann II™ UK Military Pattern External Fixator packs. Stand facing the casualty's feet with your pelvis adjacent to their lateral chest wall. Identify the anterior superior iliac spines (ASIS). Follow the iliac crest two finger breadths back from the ASIS. Make a 4 cm long incision centred over this point, perpendicular to the iliac crest. 2. The aim is to insert three pins in both iliac bones (Figure 1305). In order to obtain maximum purchase, each pin must lie between the inner and outer tables of bone. To help you judge the required angle of insertion and bone thickness, probe the position of the inner and outer tables of the iliac wing using the pin mounted on the chuck. Alternatively, use a hand-placed K-wire left in-situ to act as a guide to the correct angle. 324

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1/3 2/3

x 2x

Fig 1306 Distraction at the sacroiliac joint in an “open book” pelvic injury: anteroposterior position of pins inserted in the ilium prior to reduction.

3. Steady the first pin on the bone. The point of bone entry should be at the junction of the outer 2/3 and inner 1/3 of the pelvic brim - i.e., stay closer to the inner table (Figure 1306). The pins are self-drilling; let the pin find its own way between the inner and outer tables. The aiming point is the thickest area of supra-acetabular bone. The pin should be inserted until all of the thread is buried in the bone. 4. Place a second and then a third pin, each spaced some 2-3cm behind the other. Separate incisions are needed for each pin. The pins should be generally convergent, (Figure 1305). Attach a short bar to these pins with the pin-to-bar clamps. 5. Reduce the pelvis by internal rotation of the legs. Ask an assistant to compress the posterior halves of the iliac wings together (i.e., do not lever on the pins to aid reduction - only to hold). Add a bar-to-bar clamp to each cluster of pins (Figure 1307). Attach a long bar to each bar-to-bar clamp and angle them so that they meet between the umbilicus and pubis. Clamp the two long bars together as an inverted V with a third bar-to-bar clamp. 6. Make any final adjustments and securely tighten all clamps. Reinforce the anterior long bars with a second V- Frame mounted behind the first. 325

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1307 Final assembly of the external fixator prior to reducing the pelvis.

1320 Pin care Release any tight or tented skin from around the pins with a blade. Lengthy incisions may be partly closed. Spray each wound with Povidone™ iodine. Cut 2cm strips of dry gauze and loosely wrap them around the base of each pin. These dressings should be changed daily, any crusts removed, the skin cleaned with saline and Povidone iodine reapplied. Pin tract infection is managed by saline wound toilet, bacteriological culture and appropriate oral antibiotics.

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Urological Trauma

Introduction

1401 Injury to the urogenital system occurs in Always consider approximately 3% of casualties. The kidneys, ureters, urological trauma bladder and posterior urethra are retroperitoneal or in casualties with pelvic structures. Because they are protected by the penetrating wounds of the back, loin, spine, lower ribs, pelvis and muscle, considerable buttock and those blunt force is required to produce injury. Adjacent with pelvic fractures. organs are frequently injured obscuring the urological damage. The management of the associated injuries frequently takes precedence. It follows that the majority of casualties who have suffered significant urological trauma need urgent surgical intervention. If in doubt, get them to a surgeon who can control their non-compressible haemorrhage.

Renal Trauma

Aetiology 1402 Renal injury may be: Blunt: This accounts for 90% of civilian renal injuries in the UK. Forty percent have serious, associated Absence of injuries. Trauma may be direct or indirect. Examples haematuria does not exclude urological of direct injury include: a blow beneath the ribs or a trauma. There may crush between the 12th rib and lumbar spine. Rapid be few signs. deceleration may injure the kidney indirectly by avulsing the renal vessels, rupturing the ureter at the pelvi-ureteric junction (PUJ), or by causing an intimal tear of the renal artery. Damage is more likely if the kidney is abnormal, or in children, who have limited perinephric fat and less protection from surrounding tissues. 327

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Penetrating: The majority are missile injuries; a few An APC fracture of the pelvis (1305), are stab injuries. The kidney is involved in 4 to 8% points to possible of penetrating abdominal and thoraco-abdominal bladder or urethral wounds. Approximately two-thirds have associated damage (or both). injuries (in descending order: colon, liver, lung, spleen, small bowel, stomach, pancreas, duodenum and diaphragm). In the majority, the associated injuries are the cause of the reported relatively high mortality (30%), rather than the renal injury itself. High available-energy missiles with their potential for shock-wave and temporary cavity effects, are capable of causing massive disruption of the renal substance and avulsion of the renal vascular pedicle and ureters.

Clinical features

Isolated renal trauma 1403 Renal injury is suggested by: is an uncommon cause of shock. • History - the mechanism of injury. If present, the probability of • The site of entry and exit wounds, abrasion, associated injuries contusion, haematoma or bruising affecting the is high. upper abdomen, loin or lower chest. • Macroscopic haematuria (90% of cases). • Loin pain and tenderness. Passage of clots may cause ureteric colic. • Loss of loin contour or a mass due to haematoma, urinoma or both. • Associated fractures of the lower ribs and/or lumbar transverse processes. Not uncommonly, the diagnosis is made at laparotomy and, less commonly, at thoracotomy.

1404 Based on an intravenous urogram (IVU), ultrasound and/or CT scanning, injuries can be classified into three functional groups. Figure 1401 illustrates some examples. The approximate frequency of these injuries in peacetime is given 328 in brackets:

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AB

CD

E

Fig 1401 Types of renal injury: Minor: A contusion and superficial laceration. Major: B. deep laceration. C. Penetrating injury. Life-threatening: D. Pedicle avulsion. E. Renal fragmentation.

1. Minor (85%): Contusions and superficial lacerations of the renal parenchyma not involving the pelvicalyceal system and with an intact renal capsule. 2. Major (10%): Deep lacerations affecting parenchyma and capsule. There may be extension into the collecting system. 3. Life-threatening (5%): Renal fragmentation and pedicle injury (vascular avulsion, rupture of PUJ). 329

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• The perirenal (Gerota's) fascia usually prevents blood and urine escaping from around the kidney. A large retroperitoneal urinoma and/or haematoma may cause an ileus. • After a penetrating injury, blood and urine track in all directions and may enter the peritoneal cavity. This can result in abdominal rigidity and ileus. • The renal outflow may become obstructed by blood clot in the renal pelvis or ureter. Cessation of haematuria may suggest improvement when, in fact, the casualty is losing renal function.

Slight haematuria Management of blunt renal injury or blood found on microscopy or 1405 With the exception of parenchymal Dipstix, usually fragmentation and pedicle injury, 90-95% of blunt indicates minor renal trauma can be treated conservatively. urological trauma which will resolve spontaneously. Minor renal trauma 1406 In the field, investigate all those with slight haematuria or blood on microscopy or urine Dipstix testing (see below). Casualties should remain on bed rest and antibiotic treatment until the haematuria has resolved. They may return to duties if clinically and haemodynamically stable. Warn of the small risk of secondary haemorrhage or severe haematuria occurring up to three weeks after injury.

Major or life-threatening renal trauma 1407 Casualties with definite haematuria ± shock: • Resuscitate: this may involve urgent laparotomy in the unstable casualty. • Analgesia (Figure 0701). • Regular monitoring: pulse, BP, inspection of the abdomen (e.g., increasing loin mass) and serial observation of the urine. A change in colour from 330

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red to brown usually indicates that haematuria is settling. • Bed rest until haematuria has settled. • High fluid intake to avoid clot colic. What to look for • Prophylactic antibiotics (0820). on the control film and IVU: • Stage the renal injury by IVU, ultrasound and/or Is there a functioning spiral CT (if available). Perform an early IVU with contralateral kidney? 100ml of contrast (not diagnostic if the systolic Adjacent fractures. BP <90mmHg). Take two films within 5 minutes Loss of psoas and a third at 15 minutes. Unilateral absence of shadow/renal outline. function suggests serious disruption of the Bowel displacement. kidney or its blood supply and the need for early Distortion of calyces. laparotomy (NB: a solitary kidney occurs in Extravasation of contrast. 1:1200, almost invariably with compensatory Non-visualisation or hypertrophy of the single kidney). In 85% of delay in appearance casualties the IVU will be normal. This does not of nephrogram or mean that the kidney is uninjured. Ultrasound or pelvi-calyceal CT may reveal a renal tear, haematoma or system. perirenal collection. Serial scans are used to monitor resolution.

Surgery following renal trauma 1408 Exposure of the kidney through a mass of blood clot is not easy. • The decision to operate depends on the If you are forced to casualty's clinical condition and, if time allows, explore the kidney, the results of IVU, ultrasound and CT. the priority is to stop Indications include: bleeding. This may mean damage • Penetrating renal injury. control surgery by packing. Wound • Haemodynamic instability. excision, repair of ureteric injuries • Uncontrollable haemorrhage or nephrectomy can or enlarging haematoma. be delayed until a second look. • A shattered kidney or damage to the renal pedicle.

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• Significant haematuria causing a continuing fall in haemoglobin. • Because the likelihood of other intra-abdominal injuries is high, approach through a full-length midline incision (1225). Do not open a large, pulsatile perirenal haematoma without first controlling the renal pedicle(s). • Eviscerate the small bowel on its mesentery to the right and cephelad. Incise the posterior peritoneum from the caecum to the ligament of Treitz (Figure 1232). This gains access to the aorta, inferior vena cava and origins of the renal vessels. Control the renal pedicle vessels on the affected side(s). This permits Gerota's fascia to be opened without the threat of torrential haemorrhage. With small, non-pulsatile haematomas, the kidney can be approached directly, (Figure 1402). Options now are: • Suture the laceration(s). • Carry out a partial nephrectomy. • If 1 and 2 are not possible, ligate the renal vessels and carry out a nephrectomy.

1409 Ideally, renal lacerations should be excised and closed with deep absorbable sutures on a blunt needle (Figure 1403). Do not tie too tight or use mattress sutures, they tend to cut out. Aids to haemostasis and closure include: tying over perirenal fat, muscle or omentum. The perinephric space should be drained through a separate loin incision.

1410 If the pedicle has not been controlled and there is heavy renal bleeding, apply pressure with packs over the kidney without opening Gerota's fascia. Re-explore 24-48 hours later once the casualty is stable. By this stage, bleeding will usually have stopped and it may be possible to repair the 332 kidney. Failing that, carry out a nephrectomy.

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Division of peritoneal reflection Right kidney

A)

Inferior vena cava

Aorta

B)

Left Kidney

C)

Inferior vena cava

Aorta

D)

Right renal vein Left renal vein Left renal artery Right renal artery Inferior vena cava Aorta E)

Fig 1402 Exposure of the renal pedicle and kidneys: Right kidney: A. The hepatic flexure is mobilised and the duodenum "Kocherised". B. The colon and duodenum are retracted to expose the kidney and renal vessels. Left kidney: C. The splenic flexure is mobilised. D. The bowel is retracted inferiorly. E. The most common relationships of the renal vessels, aorta and IVC. 333

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Fig 1403 Repair of a renal laceration. The wound is excised. Close with interrupted deep sutures on an atraumatic needle. The defect can be covered by omentum. Drain

1411 When performing a nephrectomy, transfix or double ligate the artery and vein separately. Tie off the distal end of the ureter using an absorbable ligature. Drain the renal bed through a separate stab incision.

1412 The only absolute indication for a partial Absence of renal nephrectomy (Figure 1404), is a solitary functioning perfusion for >30-60 minutes may cause kidney. This requires time and expertise and can permanent loss result in greater blood loss than a nephrectomy. of function. If it can be identified ligate, and divide the artery to the damaged segment. Remove non-viable tissue by finger fracture or a wedge or guillotine incision. Drain the renal pelvis via a nephrostomy tube (e.g., Foley catheter) gently introduced through the renal substance using forceps. Repair the pelvi-calyceal system using fine absorbable sutures. Close the kidney with deep absorbable sutures tied over crushed muscle or omentum. 334

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Line of division

A)

B)

C)

D)

Fig 1404 Technique of partial nephrectomy. A. The segmental vessels are ligated and divided. The kidney is divided using finger fracture. B&C. The collecting system and capsule are closed separately. Reinforce with crushed muscle or omentum. D. the renal pelvis is drained with a nephrostomy. If flaps of the renal capsule are available, use these to cover the defect. Drain the perinephric space through a separate incision. 335

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Fig 1405 Ureteric repair: Spatulate and insert stay sutures. Repair using 4-8 interrupted absorbable sutures.

1413 Repair of renal vessels depends on time and experience. Nephrectomy is usually more appropriate.

1414 If an unexpected perinephric haematoma is encountered during the course of a laparotomy, observe for several minutes and, in a stable casualty, perform an on-table IVU. If the haematoma remains static and the X-ray does not show serious injury, it should be left undisturbed. The intact peritoneum and perinephric fat will usually tamponade the bleeding and prevent contamination. Unwisely incising the peritoneum may cause catastrophic 336 haemorrhage and circulatory collapse (1274). Chapter_14.qxd 28/09/2004 15:56 Page 337 14: Urological Trauma

1415 Complications of renal trauma Early: secondary haemorrhage due to infection - may require surgery or, if available, selective arterial embolisation; urine leak (generally settles) and abscess formation (drain). Late: (>6 weeks) hypertension, arteriovenous fistula, hydronephrosis, pseudocyst formation, calculus formation, chronic pyelonephritis and loss of renal function.

Ureteric Injury

1416 Ureteric trauma is uncommon. Clinical signs are often absent in the early stages and may only The ureters can usually be identified become apparent when the casualty presents with as narrow tubes loin pain, abdominal swelling or a urinary fistula where they pass several days later. The torn ureter may become over each of the obstructed by adjacent haematoma or urine common iliac arteries. They can collection. A missed diagnosis usually results in then be followed loss of the kidney. Iatrogenic injury typically occurs proximally and if the surgeon has failed to identify the ureters during distally. Typically, colonic mobilisation or pelvic surgery. peristalsis is seen when they are pinched. Management

1417 The diagnosis can usually be confirmed Principles of ureteric by IVU (but not always). repair: - No tension. Consider, depending on the extent of trauma and - Spatulate ends. presence of multiple wounds, whether the whole - Stent across repair. length of the ureter needs to be examined. - Take Care If detected at the time of injury, mobilise both ends of the ureters to avoid carrying out an anastomosis under tension. Trim and spatulate and hold with two stay sutures (Figure 1405). A straight end-to-end anastomosis is liable to stenose. Pass a Double- J ureteric stent across the defect to reach the renal pelvis and the bladder (Figure 1406). Anastomose using a single layer of interrupted fine absorbable sutures (e.g., 5/0 PDS). NB: 4-8 should be sufficient. 337 Chapter_14.qxd 28/09/2004 15:56 Page 338 14: Urological Trauma

Fig 1406 Place a Double-J stent across the ureteric repair.

Leave a tube drain (not a suction drain) close to the injury. The ureteric stent can be removed 10-14 days later.

1418 Depending on the level of ureteric injury, limited loss of ureteric length can be compensated for by mobilisation of the kidney and, at the distal end, relieving tension by a psoas hitch-stitch or Boari flap procedure (Figure 1407). Options if the defect is too wide include: • Bring the end of the ureter out to the skin as a temporary measure and suture it with a stent or tube in place to aid drainage (Figure 1407). Subsequent repair should be carried out by 338 a urologist. 14: Urological Trauma 339 C) A) B) B. Cutaneous ureterostomy. B. Cutaneous ureterostomy. C. Uretero-ureterostomy. Fig 1407 A. Boari flap operation. Chapter_14.qxd 28/09/2004 15:56 Page 339 Page 15:56 28/09/2004 Chapter_14.qxd Chapter_14.qxd 28/09/2004 15:56 Page 340 14: Urological Trauma

• Anastomosis to the opposite ureter (Figure 1407). • Interposition of small bowel or appendix to bridge the gap. The first of the above options is quickly carried out. The other two are specialised, time-consuming procedures best done by a urologist at a subsequent operation. In an unstable casualty: • Nephrectomy may be the best course if the other kidney is normal.

Bladder Injury

Aetiology 1419 The bladder may be damaged by a bony fragment following a pelvic fracture, a penetrating injury, by rapid deceleration and by a direct blow to the lower abdomen. It is more vulnerable when full. The condition may initially be missed in the unconscious casualty.

Clinical features Injury of the bladder 1420 Rupture of the bladder can be intra or may co-exist with injuries to the small extraperitoneal, or a combination of both (Figure bowel, rectum, 1408). Following a pelvic fracture, the leak is usually vagina and uterus. extraperitoneal (NB: there may also be damage to the urethra). A direct blow typically causes an intraperitoneal rupture of the dome or posterior surface. Common findings are:

Even if the bladder • Acute abdominal pain and shock. is perforated, there may still be some • Lower abdominal tenderness. Following drainage of urine on extraperitoneal rupture tenderness is suprapubic; catheterisation. after intraperitoneal rupture it is more generalised Beware of clumsy and develops into peritonitis within 24 hours. attempts at catheterisation • Bleeding per urethram. Haematuria can be with failure of the due to bladder contusion or injury to the ureter catheter to enter the 340 bladder. and kidney.

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Intraperitoneal rupture Extraperitoneal rupture

Prostate Rupture of posterior urethra Rupture of anterior urethra

Fig 1408 Intra and extraperitoneal rupture of the bladder. Common sites for injury to the urethra are illustrated.

• Swelling of the abdominal wall. • Inability to pass urine, failure of bladder distension or absence of urine on bladder catheterisation. • An AXR may show a pelvic fracture or the presence of a missile. • If a rupture is missed, blood and urine become infected. Pus may track to the buttock and thigh.

Management of bladder injuries 1421 Steps include: • Resuscitation (0333). • Pass a urethral catheter (NB: consider urethral injury - see 1423). • The diagnosis is confirmed by a cystogram (NB: use water soluble contrast) or IVU, demonstrating extravasation. FAST may demonstrate fluid in the pelvis (1213). Bladder injury is easily missed at laparotomy. • Start antibiotics (0820). • Perform a laparotomy. Washout the peritoneal cavity with saline. Tears in the bladder wall 341

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2-3 cm

Pubic bone

Fig 1409 Site of insertion of a suprapubic catheter. The casualty also has a urethral catheter in place.

require minimal wound excision. Repair is Management of done in two layers with a continuous absorbable life-threatening injuries take suture (NB: avoid the ureters). If you cannot find precedence. the defect, open the bladder and feel from Depending on inside; tears may be multiple. Carry out a circumstances, second lavage. treatment of lower urinary tract injuries • Insert a suprapubic catheter - a large Foley is may be delayed by up to 24 hours. The ideal. This may be introduced through a separate urine is initially stab incision, the balloon inflated and the sterile. bladder closed snugly around the catheter. A urethral catheter is also inserted (Figure 1409). • Drain the retropubic space. • Leave both catheters in place for 10 days. Remove the urethral catheter first, check that the casualty can pass urine by clamping the suprapubic catheter. Once spontaneous micturition has been established, the suprapubic catheter can be removed. • If the casualty has an extraperitoneal rupture and no other injures, this can be managed by catheterisation for 10 days and antibiotics (0820). The defect will heal itself and any urine be absorbed. If circumstances allow, confirmation of closure by a cystogram should 342 first be obtained. Chapter_14.qxd 28/09/2004 15:56 Page 343 14: Urological Trauma Urethral Injury

Aetiology 1422 Causes include: • A blow to the perineum for example, 'fall-astride' may injure the anterior urethra (Figure 1408). • 10% of pelvic fractures result in rupture of the posterior urethra. • Missile injury, e.g., mine fragments.

Clinical features 1423 These may include: Because it is short, the female urethra • Blood at the external meatus. is rarely injured. • Pelvic fracture on AXR (typically types II and III anteroposterior compression fractures 1305). • Difficulty or failure to pass urine causing bladder distension. • Bruising of the lower abdominal wall, scrotum or perineum. Later there may be extravasation of urine into these sites. • Blood in the rectum on rectal examination or the presence of palpable pelvic bone fragments. • A high-riding prostate on rectal examination, that is, a complete tear of the posterior urethra which allows the prostate to be pulled up in a cephelad direction. This sign can be difficult to elicit and a boggy swelling due to blood and urine where the prostate should be, is more likely. • Most tears are partial and usually heal with conservative treatment. • Long term complications include strictures and impotence.

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Management of urethral injury Insertion of a suprapubic 1424 Steps include: catheter may not be easy in an obese • Ask a conscious casualty to try to pass urine or restless casualty, without straining. If it is blood free, they are or when the bladder is empty. unlikely to have damaged their lower An ultrasound urinary tract. may help. • The safest option is to insert a suprapubic catheter into a distended bladder and give antibiotics. The injury can then be assessed back at Role 4 by urethrography or endoscopy. Any pelvic fracture is likely to require fixation (1317). • The experienced clinician is permitted to make one gentle attempt at passing a narrow urethral catheter (size 14F) under antibiotic prophylaxis (0817). If the rupture is incomplete, it may be possible to negotiate the tip across the defect and into the bladder. The risks in doing this are converting the injury into a complete tear and introducing infection. This is not a procedure for the unskilled; in their hands, a suprapubic catheter is safer! • Formal urethral repair should be carried out by a skilled urologist.

Technique of suprapubic catheter insertion 1425 Steps include: • Only perform a percutaneous insertion when the bladder is distended or under ultrasound control. • With the casualty supine, clean and drape the suprapubic abdominal skin. • The site of insertion is 2-3 finger-breadths above the symphysis pubis in the midline. Infiltrate the skin and deeper layers with 1% lignocaine. Advance the needle until aspiration of urine 344 confirms that you are in the right place. Chapter_14.qxd 28/09/2004 15:56 Page 345 14: Urological Trauma

• Make a 1cm stab incision in the skin and abdominal wall. Push the catheter and trochar gently into the bladder. When urine is encountered, remove the trochar, advance the catheter and secure it as appropriate. Connect to the catheter bag. • If the bladder is impalpable or ultrasound unavailable, perform an open cystotomy. This may require a GA. Make a lower midline skin incision. Incise the linea alba. Identify the bladder and insert two stay sutures. Make a small incision and introduce a Foley catheter. Close the bladder with an absorbable purse string suture.

Penile Injury

1426 The penis is seldom involved in war injuries. Laceration and partial amputation is encountered following land mine trauma. The urethra should be catheterised and wound excision carried out with closure of any defects in the corpora. Full thickness skin grafts may be necessary to provide cover if primary suture is not possible. Alternatively, the mobile scrotal skin can be used to cover penile defects.

Injury to the Testis

1427 The testes may be injured by a direct blow or by missiles - especially land mine fragments. Clinical features include pain, swelling and bruising of the scrotum. • Most blunt injuries will settle with analgesia, scrotal support and rest. Examine regularly. • Penetrating injuries require exploration. • A large and expanding scrotal swelling is due to a haematoma; it should be evacuated urgently. 345

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Administer prophylactic antibiotics (0820). Depending on the severity of injury, either undertake an orchidectomy or suture the tunica albuginea (e.g., 3/0 PDS). • If the scrotal skin is extensively damaged, carry out a wound excision and primary skin closure (0504). This can be aided by a split skin graft.

346

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Thoracic Injury

Introduction

1501 Thoracic injury accounts for 30% of civilian 10% of battlefield injuries. It is responsible for approximately 25% of all trauma fatalities and may contribute to death in a further 25%. Some casualties are unsalvageable and die shortly after injury. Others can be saved by prompt recognition of the presence of a life-threatening injury, followed by simple interventions such as application of an Ashermann seal, needle thoracocentesis or insertion of a chest tube. Only 10-15% of chest injuries require surgery for severe bleeding, or a significant air leak.

Pathophysiology

1502 Battlefield chest trauma is generally caused The chest cavity by penetrating or blast injury. The spectrum of blunt is one of the four trauma mirrors that seen in civilian practice. classic sites of Considerations include: hidden blood loss. A massive • Injury is usually obvious, with signs in the haemothorax is defined as a chest wall or thoracic cavity. Occasionally, volume >1500. trauma is occult, exemplified by a bullet that enters the neck or abdomen and continues on into the chest. Similarly, a missile may cross the mediastinum to involve the contralateral hemithorax. • The dome of the diaphragm reaches as high as the nipples and tips of scapulae during expiration. Twenty-five percent of chest wounds involve the abdomen. Remember also, the apex of the lung lies in the root of the neck behind the 347 medial third of the clavicle.

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Fig 1501 Bullet wound of the chest with secondary bone fragmentation.

Insertion of a chest • Missiles hitting the ribs or spine may change drain will allow the direction, or release secondary fragments lung to expand (Figure 1501). against the chest wall. This is often • Following crush or blast injuries, there successful in may be extensive visceral damage without compressing any sources of bleeding external wounding. or air leaks. • Because symptoms may take several hours to develop, all chest wounds and inhalational injuries (2204-2206) should be regarded as potentially serious.

Chest Injury: General Overview

Rib fractures 1503 Significant thoracic trauma commonly causes fracture of one or more ribs. The resultant pain may interfere with breathing and expectoration. Retention of secretions can lead to bronchial obstruction and pulmonary collapse. Multiple fractures are usually associated with underlying 348 Chapter_15.qxd 28/09/2004 15:56 Page 349 15: Thoracic Injury

lung damage; this is the major cause of morbidity and mortality following chest injury. Treatment: analgesia (Figure 0701) with or without support with a field dressing and/or strapping; neither must limit respiratory excursions. Intercostal nerve blocks may be of value (0736).

Flail chest 1504 This is discussed in 0327. Damage to the underlying lung is the principal cause of hypoxia in flail chest. The effects are compounded by paradoxical movements of the detached segment and splinting of the chest wall due to pain (Figure 1502).

Treatment: see 1503. Insert a chest drain (3013). Administer oxygen (0317). Subsequently, a period of positive pressure ventilation may be required (2542). Contused lung is very sensitive to over-hydration as well as hypovolaemic shock - give i.v. fluids carefully.

Pneumothorax

1505 Air in the pleural space can accumulate Chest wall defects after penetrating or blunt trauma (NB: can be 1cm in diameter bilateral). It signifies chest wall, lung parenchyma, are more likely to result in a tension tracheo-bronchial or oesophageal injury. The pneumothorax than a diminution in lung volume and vital capacity is sucking wound. If the proportional to the size of the pneumothorax. casualty has There are three types: repiratory distress perform a needle thoracocentesis 1. Simple pneumothorax followed by a chest drain. 1506 The volume of air within the pneumothorax remains unchanged. A small pneumothorax may be asymptomatic and is usually absorbed over a few days. A significant pneumothorax may be associated with chest pain and non-progressive respiratory distress. Clinically, there may be hyper-resonance on 349

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A

B

Fig 1502 Flail chest: A) A section of ribs has become detached from the rest of the thorax. B) This causes paradoxical movement of the chest wall on expiration-inspiration.

percussion and reduced breath sounds on the affected side. The diagnosis is confirmed by CXR. Treatment: in the field, insert a chest drain whatever the size of the pneumothorax (3013). This avoids the risks of expansion during unsupervised holding and transfer. 350

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Fig 1503 Open ('sucking') chest wound causing a pneumothorax; it can cause mediastinal displacement.

2. Tension pneumothorax 1507 A unidirectional valve-like laceration Absent breath sounds and in the chest wall or lung can result in a tension hyper-resonance pneumothorax. This is a life-threatening condition. can be difficult to With each inspiration, air is drawn through the defect detect in the field. into the pleural space from which it cannot escape. Distended neck veins depend on the Progressive accumulation of air causes collapse presence of a normal of the ipsilateral lung, shift of the mediastinum to circulating volume. the opposite side and hypoxaemia. The combination of high intrathoracic pressure and mediastinal shift, leads to a reduction in venous return, cardiac filling and a fall in cardiac output. Clinical features are shown in Figure 0311: Treatment: immediate needle thoracocentesis (3012) and closure of any external wounds (e.g., Ashermann Open wounds of the seal (3011), suture), followed by insertion of a chest chest must be closed drain (3013). or sealed. Insert chest drains 3. Open pneumothorax ("sucking chest wound") immediately in all penetrating injuries 1508 A wound between the pleural cavity and and serious blunt external environment, allowing air to enter and leave injuries (NB obtain i.v. access first). during respiration, is termed an open pneumothorax Early chest drain (Figure 1503). Air follows the path of least resistance. insertion is If the chest wall defect is greater than two-thirds the particularly important diameter of the trachea (approximate 1.5-2cm), in children and the elderly. air will preferentially flow through the wound rather 351

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than the tracheobronchial tree. This causes collapse and underventilation of the lung on the affected side(s). Pressure on the mediastinum can compromise the contralateral lung and interfere with venous return to the heart and cardiac output. Clinically, there is (usually) a sucking sound and respiratory distress. Treatment is discussed in 0325: Definitive surgery involves extending the defect into a small thoracotomy, excising the wound edges and partial closure (1516).

1509 Surgical emphysema Air escaping into the tissues causes subcutaneous crepitus and swelling. The usual cause is a pleural injury or a dislodged chest drain. A tension pneumothorax may result in dramatic inflation of the trunk, neck and face. Swelling, starting in the neck, suggests air passing up the mediastinum from a wound of the tracheobronchial tree or oesophagus. Surgical emphysema is not dangerous; once the cause is treated, the air rapidly absorbs.

Haemothorax 1510 Blood in the pleural space may originate from the lung or vessels in the chest wall or mediastinum. A traumatic haemothorax is usually secondary to bleeding from intercostal or internal mammary vessels. Bleeding generally occurs slowly and has stopped spontaneously by the time of treatment. Less commonly, life-threatening bleeding may be due to laceration of the lung, injury to the pulmonary hilum, aortic disruption or cardiac wounds. The total fluid volume in the chest is increased by an associated pleural effusion. Initially, this prevents the haemothorax from clotting. Clinical features are described in 0326.

352 As the pleural space fills, there is progressive Chapter_15.qxd 28/09/2004 15:56 Page 353 15: Thoracic Injury

interference with lung expansion, inhibition of venous return and mediastinal displacement. Hypovolaemic shock and dyspnoea indicate major bleeding. A CXR will show hazy oppacification but, 500mls of blood can be easily missed, hidden behind the shadow of the diaphragm.

1511 Treatment: • The majority of casualties are successfully treated by chest drainage alone (0326). Without a CXR, • A resuscitation thoracotomy to clamp the hilum, it can be difficult to may be necessary as part of the primary survey tell the difference between a in casualties with life-threatening haemorrhage haemothorax and (1541). significant lung contusion. A chest • If, after insertion of the chest drain, there is drain is appropriate major blood loss (i.e., >1.5 litre), or evidence for both conditions. of continuous bleeding (>200ml/hour for 2-4 hours), urgent thoracotomy is required (1534). • Complications include pneumonia, ARDS, abscess formation and multi-organ failure. A haemothorax persisting for more than one week will clot and become organised, preventing lung expansion. Treatment is by early thoracotomy and decortication. Similarly, abscesses which fail to respond to tube drainage require a thoracotomy and wound toilet.

Lung injury 1512 Penetrating or blunt injury may Ensure that there is i.v. access and cause pulmonary contusion, lung laceration that you have started or disruption of the larynx, trachea and distal fluid resuscitation bronchial tree. Haemoptysis is a frequent symptom; first, as sudden it is rarely profuse. collapse can occur when the tamponade effect of the closed Pulmonary contusion hemithorax is removed. 1513 The lung is "bruised". This is a common finding after serious blunt chest trauma and is 353 Chapter_15.qxd 28/09/2004 15:56 Page 354 15: Thoracic Injury

Following blast potentially fatal. Pathological effects include injury, respiratory compromise interstitial and alveolar haemorrhage and oedema. increases with time. These result in Few who develop severe symptoms in • A progressive reduction in alveolar the first two to three membrane diffusion. hours survive. • Increased pulmonary vascular resistance. • Decreased pulmonary vascular flow. • Reduced lung compliance. • Shunting of blood through a non-ventilated lung causing a ventilation-perfusion mismatch. All of the above cause hypoxaemia. The symptoms of contusion and blast lung are similar (1514). Subsequent problems include pneumonia and ARDS. Treatment: see 1504. Complications may be prevented or attenuated by physiotherapy and antibiotics (0821).

Blast lung

In pulmonary 1514 Casualties who survive blast injury contusion, anxiety (0218) gradually develop over time, features and restlessness similar to pulmonary contusion (1513): may lead to diagnostic • Dyspnoea, chest pain, cyanosis and tachycardia. confusion with hypovolaemic shock. • Rib fractures and chest wall bruising may be absent. • Those severely affected often sit up and hold onto fixed points to aid use of their accessory muscles of respiration. • Ineffective expectoration of frothy, often blood stained mucus is common; some casualties are literally drowning in their own blood. The radiological appearance of haziness and lung mottling is usually an early feature, but can take 24 hours to become apparent. This can be confused 354 with a haemothorax (the two frequently coexist).

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Treatment is as for lung contusion (1513).

Penetrating injury 1515 Because of the elasticity and excellent blood supply of the lung, most penetrating injuries can be successfully managed by tube drainage alone. The presence of a defect in the chest wall and dirt and bone fragments in the lung parenchyma, risks the development of wound infection, pneumonia and lung abscess.

1516 Treatment: definitive surgery involves extending the defect into a small thoracotomy and excising the wound edges. Then: • Obtain haemostasis. • Inspect the underlying lung. If there is contamination, foreign bodies, bone fragments or necrotic parenchyma, explore, excise and washout through a formal thoracotomy incision (1534). Insert one or more chest drains: both apical and basal drains may be required. • Approximate the ribs in the vicinity of the penetrating wound using interrupted sutures (e.g., No 1 Vicryl). Attempt to cover the defect by closing the muscles of the chest wall in layers (e.g., continuous 2/0 Vicryl). Leave the skin open for secondary suture (0510). Occasionally, flap closure or skin grafting is required to close the defect (2305).

Laryngeal injury 1517 These are rare. Clinical features and management are discussed in 1926. Prevention of airway obstruction necessitates a tracheostomy (3007) rather than a cricothyroidotomy.

Tracheobronchial injuries 1518 On the battlefield, tracheal injuries are 355

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mainly due to penetrating injury and are often associated with concomitant injury to the oesophagus and aorta. Most casualties die before reaching Role 1. Features amongst survivors include: • Laboured respiration. • Haemoptysis. • Tension pneumothorax. The degree of air leak following • Surgical emphysema in the neck. tracheobronchial • Mediastinal air on CXR. injury may require insertion of a second • A classical sign is a pneumothorax that chest drain to prevent development continues to leak significant amounts of of a tension air after chest tube insertion. pneumothorax. Treatment: surviving casualties require surgical repair (1552).

Diaphragmatic disruption 1519 The left hemidiaphragm is more commonly The radiological appearances affected. The usual cause is a compressive of stomach and abdominal injury resulting in a radial, diaphragmatic bowel in the chest tear. This allows abdominal contents to herniate can be confused with through the diaphragm into the chest, where they a haemothorax or pleural effusion, risk strangulation. Smaller diaphragmatic tears often leading to the present late. Clinically there may be: potentially disastrous insertion of a • Chest pain, absent breath sounds, thoracic chest drain. bowel sounds and cardiac embarrassment. • A CXR may demonstrate an altered diaphragmatic contour. • Introducing a nasogastric tube and repeating the CXR may aid diagnosis (the tube is seen in the chest) and, to a certain extent, relieve respiratory distress. When feasible, a contrast swallow may confirm the diagnosis. Treatment: is emergency surgery to reduce the abdominal contents and repair the diaphragm. 356

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The approach can be through the abdomen or chest depending on clinical circumstances (1253).

Injury to the heart and great vessels 1520 Aortic transection, great vessel rupture, hilar injury or cardiac laceration, usually result in exsanguinating haemorrhage, profound hypovolaemic shock and early death. Immediate survivors are at risk of low cardiac output, cardiogenic shock and myocardial failure.

Aortic tears 1521 The descending part of the arch is most commonly affected. Approximately 80% die immediately. If the haematoma is contained by surrounding tissue, a third of the remainder live beyond 5 days. The casualty may be asymptomatic. Suspicious features on CXR are: • Widened mediastinum. • Fractures of the first and second ribs. • Blurring of the aortic arch and hilum of the lung. • Tracheal or oesophageal deviation (e.g., a displaced nasogastric tube). • Oppacification over the apex of the lung. Assessment requires CT scanning with contrast, or arteriography. Treatment: surgical repair in a cardiothoracic unit.

Myocardial contusion 1522 Significant contusion results in arrhythmias (20%), decreased ventricular contractility and/or compliance and conduction defects. Casualties are at risk of sudden ventricular fibrillation. An ECG and elevated cardiac enzymes may suggest infarction. 357

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Treatment is rest, oxygen (0317), analgesia (Figure 0701) and care on a HDU. Casualties may need antiarrhythmics (e.g., digoxin), diuretics to relieve pulmonary oedema or defibrillation.

Coronary artery injury and occlusion 1523 Interference with myocardial blood supply can lead to tissue necrosis and infarction. Treatment is as for myocardial contusion (1522). Ischaemia may also occur as a result of reduced coronary perfusion secondary to hypovolaemia and hypoxaemia. Treatment: Give aspirin. Transfer to a unit able to provide thrombolysis.

Valvular disruption

The removal of 1524 This can result in regurgitation, acute as little as 15-20ml congestive cardiac failure and death. Some valvular of blood from the lesions are only diagnosed months or years after pericardial sac can dramatically benefit the event. the circulation. Treatment: surgical repair in a cardiothoracic unit.

Cardiac tamponade

When performing 1525 Blood in the intact, inelastic pericardium can pericardiocentesis, it obstruct venous return and interfere with normal atrial can be difficult to tell filling (0328). Beck's triad may be difficult to detect. if the aspirated blood is from the Differential diagnosis is from a tension pneumothorax. tamponade or the Where the casualty's condition allows, confirm by ventricle. Aspiration FAST (1213). may be unsuccessful if the haematoma is Treatment: is described in 0328. organised. Oesophageal disruption 1526 This uncommon injury is usually caused by direct penetration. It is occasionally due to increased pressure at the gastro-oesophageal junction secondary to blunt abdominal injury, or as a result of forceful retching. Features include: 358 Chapter_15.qxd 28/09/2004 15:56 Page 359 15: Thoracic Injury

• Severe chest and/or epigastric pain, Casualties with small penetrating wounds often out of proportion to the apparent injury. of the heart can • A CXR may show a left-sided pneumothorax or survive following pericardiocentesis haemothorax without any associated rib fracture. without the need There may be air in the mediastinum. for an immediate thoracotomy. • Mortality is high. A lethal mediastinitis can develop within hours. Treatment: the level and side of the perforation is identified by a contrast swallow or endoscopy. Urgent surgical repair is most likely to produce a live casualty. Where surgical expertise is unavailable, treat casualties medically (0000).

Management of Thoracic Injury

Overview 1527 The priority is to manage ABC, especially at Roles 1 and 2 and to get those casualties most likely to need operative treatment to a surgeon. Early transfer on suspicion of serious chest trauma alone is justified. Get a History ("MIST" 0301), perform a primary survey (ABC 0302) and start life-saving treatment (0317). Remember: most lives are saved by simple interventions - application of an Ashermann seal, needle thoracocentesis or insertion of a chest tube. If facilities allow, a resuscitation thoracotomy (1541) may be indicated for major bleeding or air leak. NB: most suspected thoraco-abdominal injuries are initially managed by laparotomy plus insertion of a chest tube. Where appropriate: (1) Apply a field dressing or Ashermann seal to the chest wound(s) (3011). 359

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(2) Perform needle thoracocentesis (3012). (3) Perform pericardiocentesis -rarely required in the field and probably ineffectual in most cases (3015). (4) Undertake a full secondary survey, including the casualty's back and sides. (5) Insert one or more chest drains (3013). NB: there may be bilateral injury. (6) If the situation allows, package the casualty before transfer. This may require all of the above, plus analgesia (Figure 0701) and antibiotics (0821). (7) Keep NBM in case of surgery. Sips of water <30mls/hour to moisten the mouth are permitted. Wounds to the chest may have caused (8) Organise transfer to a surgical facility; abdominal and If possible, discuss casualties with a member spinal injuries. of the surgical team. Record findings and management. Decision making: this will be influenced by the Role (level or echelon) at which the casualty is being managed and the operational scenario. For example, in a war-fighting situation, an immediate thoracotomy at Role 1 is not tenable. Equally, casualties in this category are unlikely to survive transfer to a surgical facility. Conversely, in a mature military operation where casualty transfer can be rapid, immediate thoracotomy may need to be part of the decision making algorithm. The following should be read with this in mind.

1528 Having assessed the casualty, you must decide whether they: • Require immediate thoracotomy as part of the primary survey. • Require emergency thoracotomy. 360

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• Have thoracic injuries requiring non-surgical treatment. • Do not have significant thoracic injury.

1529 Indications for immediate thoracotomy After resuscitative (1541) are: thoracotomy, close the chest using • Cardiac arrest following an isolated penetrating a single layer chest injury. The casualty must have displayed technique; the majority of survivors signs of life in the last five minutes, otherwise will be formally surgery is futile. re-explored in theatre. • Life-threatening haemorrhage into the chest which appears uncontrollable by means other then hilar clamping. Blunt thoracic trauma is a relative contraindication to immediate surgery. In the majority of cases who Few casualties who undergo are in extremis, the injuries will not be repairable a resuscitation and the continued blood loss from lacerated thoracotomy outside pulmonary and intercostal veins enormous. of the operating Control of large volume haemorrhage under theatre survive. Also there is a suboptimal conditions is usually impossible. higher incidence of complications. 1530 Indications for emergency thoracotomy are: • Major blood loss following chest drain insertion (>1.5 litres). • Continued bleeding from the chest drain (200ml per hour for 2-4 hours). • Massive air leak or obvious airway injury. • Oesophageal perforation. • Foreign body transfixion. • Cardiac tamponade following penetrating or blunt trauma. • Aortic disruption. Attempts to deal with the first six can legitimately be made in a field setting. Ideally, the last requires confirmatory arteriography and facilities for partial or 361

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Major or continuous complete cardiopulmonary by-pass. Hypotensive thoracic bleeding is due to injury to: treatment and rapid transfer are the best that can Heart be offered in an austere environment. As a last Great vessels resort, cross-clamping of the aorta and synthetic graft Descending aorta insertion ('cut and stitch') may be tried (1546). There Hilum is significant risk of brain and spinal cord ischaemia. Lung parenchyma This approach probably amounts to futile care. Intercostal/internal mammary vessels Investigations 1531 If the casualty's condition allows or there is diagnostic doubt, consider: CXR: ideally, an erect PA not AP view, (plus lateral and oblique views). Examine: • Bones: look at ribs, clavicles, vertebrae and scapulae. • Soft tissues: pleura, diaphragm, lung parenchyma, heart and mediastinum. Look for absent vascular markings and a visible lung edge (pneumothorax). Hazy oppacification suggests a haemothorax or lung contusion. • Mediastinum: widening may signify aortic injury. NB: false positives and negatives are common. The mediastinum appears wider on supine or sitting CXRs, compared to erect films. • Make sure tubes - nasogastric, endotracheal, chest drain and central line - are in the right place. Look for foreign bodies. AXR: particularly following penetrating injury. ECG: Assess myocardial damage and look for arrhythmias. FAST: can be used to detect cardiac tamponade (1213).

1532 Reassess ABCDE at each Role of care and perform a full secondary survey. At Role 3 (and 4), 362 consider the need for specialist investigations: Chapter_15.qxd 28/09/2004 15:56 Page 363 15: Thoracic Injury

• CT: may be of value in the stable casualty to detect parenchymal, pleural and mediastinal injuries. • Cardiac enzyme assays; an increase may indicate myocardial contusion or infarction. • Aortography to exclude injury to the aortic arch and great vessels. • Contrast swallow for oesophageal leak and to detect herniation through a ruptured diaphragm. • Endoscopy: bronchoscopy; OGD to identify an oesophageal perforation.

Principles of thoracotomy for trauma Approach and instrumentation 1533 The casualty should be anaesthetised and intubated. A double lumen tube allows the lung on the affected side to be collapsed. Alternatively, a single lumen endotracheal tube is advanced down the main bronchus on the healthy side. If necessary, ketamine anaesthesia may be used, providing one lung is uninjured. (2520) Prepare and drape the skin as appropriate. Have ready a scalpel, dissecting forceps, haemostats, self-retaining rib retractor (e.g. Finochietto), lung retractors and large straight and side-swiping vascular clamps to control the hilum or aorta. Performing a median sternotomy requires a sternal saw, Gigli saw or Lebsche knife. Important adjuncts are good assistance, lighting and diathermy. An anterolateral thoracotomy through the fifth intercostal space is the usual approach for chest trauma. The incision can be: • Performed on the supine casualty without the need for a sternal saw. • Enlarged posteriorly for access to the posterior mediastinum. 363

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• Converted into a bilateral anterior thoracotomy ('clam shell') so as to expose the pericardium and contralateral hemithorax. • Extended across the costal margin to expose the abdomen, (thoraco-abdominal incision see 1226 and 1553). • Combined with a separate abdominal incision. A median sternotomy is used by cardiac surgeons to expose the heart and great vessels (1538). A subclavicular ‘trapdoor’ incision may be used to access the origins of the subclavian vessels, especially on the left (1540).

Left anterolateral thoracotomy 1534 Steps include • Place wedges, sandbags or fluid bags under the ipsilateral shoulder and buttock so as to rotate the casualty by 30 degrees (Figure 1504). • Incise over the fifth intercostal space (ICS) in the inframammary crease using a blade or diathermy. Start at the left edge of the sternum anteriorly and continue to the mid-axillary line laterally (Figure 1504); if necessary, this can be extended posteriorly to just below the tip of the scapula. Follow the contour of the upper border of the rib. • Divide fibres of serratus anterior and latissimus dorsi in the line of the wound. Incise the intercostal muscles down onto the periosteum of the upper border of the sixth rib. • Pass the periosteal elevator (Rougine) anteriorly and posteriorly to free the ligamentous attachments at either end of the wound. The internal mammary artery (IMA) runs parallel to the costal margin and usually requires ligation.

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Arm for anaesthetic access Sandbag or pillow supporting casualty at 30°

Anteriolateral thoracotomy through 5th inter-space

Fig 1504 Anteriolateral thoracotomy: position on the operating table and site of incision.

the lung, which will fall away from the chest wall. Insert the rib retractor and open it fully, Iatrogenic rib fracture is common at this stage. • On the left, the lung can be retracted posterolaterally to expose the pericardial sac and heart. Improved access is obtained by dividing the sternum (1537).

Right and left posterolateral thoracotomy 1535 The position and incision on the right is illustrated in Figure 1505.

Thoracotomy closure 1536 Steps include

• Check for haemostasis and perform saline lavage. 365 Chapter_15.qxd 28/09/2004 15:56 Page 366 15: Thoracic Injury

Trapezius Incision Serratus anterior Latissimus dorsi

Fig 1505 Posterolateral thoracotomy: position on the operating table and site of incision. The muscle layers requiring division are shown.

• Insert a large bore chest drain (e.g., 36 French). If significant bleeding is encountered, or lung resection or repair (tractotomy) have been undertaken, use two drains. One directed apically ('apical and anterior for air - AAA') and one directed basally ('basal at the back for blood - BBB'). The drains should be inserted anterior to the mid-axillary line for ease of nursing care and casualty comfort, preferably three spaces below the incision. Fix them to the skin as shown in Figure 1506 and Figure 3022. Pull on latissimus dorsi with a clip so as to maintain 366 its normal position during drain placement.

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Fig 1506 Thoracotomy closure: The ribs are approximated. Three strong absorbable sutures are placed around the ribs. Close the muscle layers individually. Secure the drain by suture to a woven adhesive 'flag' around the tube, using the 'double-knot' technique.

• Approximate the ribs using three strong absorbable sutures (e.g., No 5 Ethibond) passed around the ribs above and below (Figure 1506). Re-inflate the lung. Close trapezius, latissimus dorsi and serratus anterior muscles separately. This will reduce pain and maintain shoulder function. The skin is approximated with a running blanket stich or skin staples. If speed is required, perform a mass closure of the skin and deep layers using mattress sutures. • Perform a CXR at the end to check for fluid collections, pneumothoraces and the drain positions. Casualties often continue to be ventilated during transfer; functioning drains are essential in this case.

Bilateral anterolateral thoracotomy (submammary/ clamshell/ suitcase handle incision), (Figure 1507). 1537 Steps include: • Place the casualty in the supine position and position sandbags so as to arch the back.

• The incision follows the line of the fifth ICS from 367

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Fig 1507 Bilateral anterolateral thoracotomy.

the left to the right anterior axillary lines. Steps in opening up each hemithorax are as for an anterolateral thoracotomy (1534). • Divide the sternum using a Gigli saw, bone shears or heavy scissors. Both internal mammary arteries will require ligation. • Open the wound using two self-retaining rib retractors.

Median sternotomy 1538 Steps include • Incise skin and subcutaneous tissues from the suprasternal notch to below the xiphoid process, (Figure 1508 A). • Identify the decussation of the pectoral muscles. Mark the sternal periosteum in the midline. • Incise the upper 5cm of the linea alba and divide the xiphisternum. Develop a plane between the posterior aspect of the sternum and pericardium using blunt, finger dissection. • Divide the sternum longitudinally using an 368 electric sternal saw. Other options include: Chapter_15.qxd 28/09/2004 15:56 Page 369 15: Thoracic Injury

Incision for Possible median sternotomy wound extensions

A

B

Fig 1508 A) Median sternotomy and possible extensions. B) Dividing the sternum using a Gigli saw.

a Gigli saw (Figure 1508 B) or Lebsche knife. Protect underlying structures. In young children, the cartilaginous sternum can be divided with heavy scissors.

• Divide the thymus Application of bone (NB: this can be sizeable in children). wax to the sternal edges will aid Avoid damaging the brachiocephalic vein. haemostasis. • Open the chest using a self-retaining retractor. Sweep away fatty tissue using a swab to expose 369 Chapter_15.qxd 28/09/2004 15:56 Page 370 15: Thoracic Injury

the pericardium and left and right pleurae. The pericardium and pleura can safely be opened after first picking up the membrane between clips. • Options for extending the median sternotomy incision are shown in Figure 1508 A.

Sternotomy closure 1539 Steps include • Check for haemostasis and perform saline lavage. • Insert a mediastinal tube drain anterior, and a pericardial drain posterior to the heart (24-28F). These are brought out through the skin either side of the midline below the xiphoid process. Where indicated, drain the pleural cavity(s). The pericardium is left open to avoid tamponade. • Approximate the sternum using 6-8 horizontal wires or No 5 Ethibond sutures. Close the subcutaneous tissues in two separate layers with absorbable sutures. Repair the linea alba. and close the skin with a blanket stitch or staples. For speed, use mattress sutures to close the skin and deep layers.

Subclavicular ’trapdoor’ incision 1540 Exposure of the arch of the aorta and origin of the great vessels is via a median sternotomy. The distal subclavian vessels can be exposed by a supraclavicular approach (1040). Access to the origin of the left subclavian artery and vein is sometimes achieved by a 'trap-door' incision (Figure 1508): • Perform a left supraclavicular incision (Figure 1016). Divide the sternocleidomastoid, strap muscles and scalenus anterior muscle (1040). Either dislocate the sternoclavicular joint, or resect the medial half of the clavicle 370 (Figure 1017). Chapter_15.qxd 28/09/2004 15:56 Page 371 15: Thoracic Injury

• Perform a left anterior third space thoracotomy. • Divide the manubrium and upper sternum. • Retract the three ribs laterally.

Resuscitative thoracotomy 1541 Steps include: • Perform a left anterolateral thoracotomy (1534). • Insert a hand and feel for the pericardium. Incise it using scissors. This will release any cardiac tamponade. Palpate through the open pericardium for a laceration in the heart and occlude it digitally until it can be repaired. Transfer to the operating theatre for definitive surgery. • If cardiac contractions are absent, perform internal cardiac massage. This is more effective inside the pericardium. Using your fingers, squeeze the ventricles gently at a rate of 60/minute. Alternatively, place your hand behind the heart and compress it against the sternum, or perform bimanual massage. • Torrential pulmonary bleeding can be controlled by hilar clamping (1549).

Definitive Thoracic Procedures for Trauma

Cardiac tamponade 1542 Emergency treatment can be attempted by needle pericardiocentesis (3015). ECG monitoring is required. Many now prefer to go directly to an open drainage approach. The two open approaches are: Subxiphoid Under local or ketamine anaesthesisia, make a short 371

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Fig 1509 Emergency control of cardiac haemorrhage using the surgical finger or a balloon catheter. An alternative for the low pressure atrium is to use a clamp. The atrium is repaired in two layers.

midline epigastric incision inferior to the xiphoid (Figure 3023). Incise the linea alba and by a combination of scissors and finger dissection work up towards the pericardium. Stay close to the back of the sternum. The bulging pericardial sac is incised to release the tamponade. Transfer to the operating theatre for a definitive thoracotomy. Transthoracic Perform a left anterolateral thoracotomy (1534) or a median sternotomy (1538). Identify and protect the left phrenic nerve posterior to the pericardial fat pad. 372 Make a vertical pericardial incision, parallel to but Chapter_15.qxd 28/09/2004 15:56 Page 373 15: Thoracic Injury

at a safe distance from, the phrenic nerve. Extend the incision superiorly and inferiorly and enlarge the window by a transverse extension (inverted 'T'). Suck out all the pericardial blood and clots and irrigate with normal saline.

Cardiac laceration 1543 Temporary control may be obtained by digital occlusion (Figure 1509). Alternatively, insert a balloon catheter (e.g., Foley catheter) through the defect into the ventricular or atrial cavity, inflate the balloon and apply gentle traction (Figure 1509). This may allow enough time for transfer to the operating theatre.

Atrium 1544 The atrium is a low pressure compartment; control bleeding with a vascular clamp (Figure 1509). Suture the laceration in two layers with 3/0 Prolene, using an over-and-over technique. Because the atrium is thin walled and sutures tend to cut out, insert and tighten them carefully.

Ventricle 1545 Clamping is not applicable to the high pressure ventricles. • Oversew using a Z-stitch or inverted mattress sutures. Move the occluding finger to expose a small portion of the wound (Figure 1510). Insert 3/0 double-ended Prolene sutures reinforced with Teflon™ pledgets or small squares of pericardium on either side of the defect. Take sufficient bites through the ventricular muscle to prevent 'cutting through'. Repeat until the defect is closed. • Suturing wounds close to the coronary arteries risks inclusion or injury. A safe technique is to place horizontal mattress sutures reinforced with 373 Chapter_15.qxd 28/09/2004 15:56 Page 374 15: Thoracic Injury

Fig 1510 Closing a cardiac defect: digital pressure reduces haemorrhage. The finger is gradually moved along the wound as the sutures are tied.

pledgets deep to but not across the vessels (Figure 1511).

Injury to the aorta and great vessels Thoracic aorta 1546 Repair is a specialist cardiothoracic procedure usually requiring cardiac bypass. The essential steps are: • An extended left anterolateral thoracotomy.

374 • Because disruption generally affects the Chapter_15.qxd 28/09/2004 15:56 Page 375 15: Thoracic Injury

Fig 1511 Technique of suturing close to coronary vessels.

descending aorta, proximal control is usually There is a 10% risk obtained by placing a sling or clamp between of paraplegia during the left common carotid and left subclavian aortic cross clamping arteries. Sling or clamp the aorta distal to the and repair. haematoma. Repair the aorta end-to-end with 3/0 Prolene or by inserting a woven Dacron graft. Aortic sutures should be re-inforced with pledgets.

1547 Controlling severe abdominal bleeding Aortic clamping via a left anterolateral thoracotomy may be appropriate in a minority of casualties (1276).

Injury to the origin of the great vessels 1548 The safest option is to obtain proximal control via a median sternotomy (1038). Possible extensions include (Figure 1508): • Along the sternocleidomastoid muscle to approach the carotid and jugular vessels (1038). • Above the right clavicle to expose the right subclavian artery and vein (1040). 375

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1512 Emergency clamping of the hilum following severe lung injury

• Above the left clavicle to access the left subclavian. An alternative is a trapdoor incision (1540). In wounds of the neck affecting Zones 2 and 3 (Figure 1906), it may be appropriate to explore the neck first (1038).

Lung injury Hilar clamping 1549 This is used to control life-threatening bleeding and air leaks. Hilar clamping is a routine, first step prior to major lung surgery. Following hilar clamping, early Perform an anterolateral thoracotomy (1534). Divide definitive surgery is the inferior pulmonary ligament and free the lung required before the from any adhesions. Encircle the pulmonary artery, onset of lung ischaemia. pulmonary veins and main-stem bronchus using your finger and thumb. Control the hilum with a vascular clamp or sling (Figure 1512). 376 Chapter_15.qxd 28/09/2004 15:56 Page 377 15: Thoracic Injury

A

B

Fig 1513 A) Using stapling devices to perform a non-anatomical peripheral lung resection. B) Clamping and excising damaged lung. The line of resection is closed using two layers of sutures.

Repair of lacerations

1550 Insertion of a chest drain will allow the After lung injury, lung to expand against the chest wall. This is usually every attempt should successful in compressing most sources of bleeding be made to preserve lung parynchyma. or air leaks. Where necessary, lacerations are approached by an extended anterolateral (1534) or posterolateral (1535) incision. 377 Chapter_15.qxd 28/09/2004 15:56 Page 378 15: Thoracic Injury

Division of lung over wound track to gain access to deeper vessels and bronchi

Ligation of vessels and bronchi

Fig 1514 Performing a tractotomy following a penetrating lung injury. This can be performed using a linear stapler or two clamps. This allows access to vessels and bronchioles along the wound track. If clamps are employed, oversew the lung in two layers.

Superficial lung lacerations can be repaired with interrupted Z-mattress sutures using 2/0 Prolene. Non-viable peripheral lung parenchyma may require a non-anatomical wedge resection. Use a linear stapler (Figure 1513). Alternatively, apply a crushing clamp, reset and oversew the edge continuously in two layers. For major and ongoing Simple closure of deep penetrating injuries risks the haemorrhage from development of an air embolism. Treatment is to the centre of the lung or unrepairable incise the lung over the wound track in order to bronchial disruption expose and control the damaged vessels and the safest option bronchioles - pulmonary tractotomy - (Figure 1514). may be lobectomy or The hilum is first controlled (1549). Insert one blade pneumonectomy. 378 of a linear stapler along the tract and attach it to the Chapter_15.qxd 28/09/2004 15:56 Page 379 15: Thoracic Injury

Fig 1515 Individual ligation and division of structures at the hilum.

second blade on the pleural surface. Close and divide the overlying lung. Alternatively, use two linear clamps and oversew the divided edges.

Lobectomy and pneumonectomy 1551 The usual indication is massive haemorrhage from multiple sites or widespread destruction of lung parenchyma. Large areas of non-viable tissue • In an emergency, perform a pneumonectomy remaining in the by stapling the hilum en masse and dividing chest risks the development of distal to the stapler. infection. • Alternatively, ligate, oversaw or staple and divide the hilar structures individually, starting with the superior and inferior pulmonary veins (Figure 1515). • For security, doubly ligate the pulmonary artery and close/divide the bronchus flush with the carina (Figure 1516). 379

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Fig 1516 Technique of flush closure of a main bronchus.

Tracheobronchial injury 1552 The priority is adequate lung ventilation. Surgery should be performed by a specialist thoracic surgeon. • Introduce an endotracheal or tracheostomy tube beyond the injury and inflate the cuff. This is best performed over a flexible bronchoscope. Alternatively, intubate the uninjured bronchus. • Improve lung expansion by inserting one or more chest drains to drain air and blood (3013) • Administer antibiotics (0821). • Assess the location and extent of the injury using a flexible bronchoscope. 380

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Fig 1517 Technique of bronchiol repair.

• A collar incision in the neck gives the best initial exposure to the trachea in the emergency situation. Combining it with a median sternotomy allows visualisation of the entire trachea (1538). If there is a disruption of one of the main stem or lobar bronchi, perform a posterolateral thoracotomy (1535). • Excise devitalised tissue. Repair using a one-layer technique (Figure 1517). Where there is tissue loss, perform an end-to-end anastomosis.

Oesophageal Injury 1553 Treatment: this is preferably by urgent surgical repair and drainage. Where expertise is unavailable or the casualty too ill to undergo surgery, the last resort is medical treatment. 381

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Medical treatment 1554 This includes: • Chest drainage. • Continued high dose antibiotics (0817). • Keep NBM; administer parentral nutrition. • Regular nasogastric aspiration. • Acid suppression (e.g., i,v. ranitidine 50mg three times daily). • Nurse sitting up. Chest physiotherapy.

Surgery 1555 Incision The approach depends on the location of the injury and damage to other organs.

The presence of • A left thoraco-abdominal incision gives a nasogastric tube good exposure to the lower oesophagus and aids identification of the collapsed gastro-oesophageal junction. Place wedges oesophagus. under the left shoulder and buttock so as to rotate the casualty by 30 degrees. Start the incision from the midline 5cm above the umbilicus to just anterior to the tip of the scapula through the 6th ICS. • A right or left posterolateral thoracotomy (1535) through the 5th ICS is used to expose the mid and upper thoracic oesophagus. • The cervical oesophagus is approached via an incision along the anterior border of either sternocleidomastoid muscle (Figure 1013). NB: there is a risk of damaging the thoracic duct on the left and the recurrent laryngeal nerve on the right. Divide the middle thyroid vessels and omo-hyoid muscle (Figure 1014). Retract the strap muscles and thyroid gland medially and the internal jugular vein and carotid sheath 382

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Fig 1518 Cervical oesophagostomy, isolation of the damaged oesophagus and drainage.

laterally to expose the cervical oesophagus behind the trachea.

1556 Procedures Where possible, lacerations should be closed primarily. • Administer antibiotics. Use interrupted, all coats absorbable sutures (e.g., 3/0 PDS). Repairs can be reinforced using a flap of parietal pleural . Perform copious lavage. Place a drain close to the repair. Keep NBM. Leave a nasogastric tube in place on free drainage combined with regular aspiration until a water soluble contrast examination 5-7 days later demonstrates no further leakage. Start parentral nutrition. • If the repair is ragged or delayed, consider closure around a 'T' tube (i.e., a ‘controlled fistula’). This can start to be withdrawn 10-14 days later. 383

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• If repair is likely to narrow the lumen, defects in the lower third can be closed by mobilising the gastric fundus and using this to patch the oesophagus (Nissan-Thal operation). • If it is not possible to perform a repair, drain the site of injury, close and divide the oesophagus in the neck and bring out an end cervical oesophagostomy (Figure 1518). Close the distal oesophagus and perform a gastrostomy for decompression and feeding. Reconstruction using stomach, colon or small bowel may be performed three months later.

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Head Injury

Introduction

1601 Head trauma is a common injury on The commonest the battlefield and is often combined with trauma mistake after head elsewhere. Helmets provide some protection; injury is to do continuing improvements in their design will further nothing. Deaths may occur because of the this protection. In combat, penetrating injury far severity of injury outweighs that seen in UK civilian practice. High or because surgery available-energy missiles cause severe disruption was too late. and are associated with a 50% mortality. Severe head injury is the most common cause of mortality following terrorist bombing incidents. Injury is usually caused by falling masonry. The outcome amongst head injury survivors is not predictable. Some casualties with extensive wounds and visible brain tissue may make a full recovery. The initial aims of head injury care are to: • Prevent secondary brain damage by maintaining ABC. • Identify those casualties who may benefit from early surgery.

Anatomy

1602 The skull contains brain, cerebrospinal fluid (CSF) and vessels carrying circulating blood. "No head injury is so severe as to be The brain is supplied by the internal carotid and despaired of, nor so vertebral arteries and drained via the internal jugular trivial as to be lightly veins. Surrounding the brain are two membranes: ignored" - dura mater in contact with the skull and a thin, inner Hippocrates. arachnoid mater (Figure 1601). The venous sinuses run in a dural sheath closely attached to the skull, 385 Chapter_16.qxd 28/09/2004 15:57 Page 386 16: Head Injury

Epidermis and dermis Galea aponeurotica Pericranium Skull Venous sinus Dura Arachnoid Brain Meningeal artery

Fig 1601 Anatomy of the scalp and skull.

with the sagittal sinus in the midline. CSF circulates in the space between the arachnoid and brain. Haemorrhage within the skull is described in relation to these layers namely, extradural, subdural, subarachnoid or intracerebral.

Types of Brain Injury

Primary 1603 This occurs at the moment of trauma; Loss of oxygenated noxious biochemical changes continue for several blood flow for more than three minutes hours afterwards. Primary injury can be: causes irreversible Penetrating. The weapon or missile breaches brain damage. the scalp, skull and dura and enters the brain. A high energy-transfer wound typically results in cavitation and extensive brain disruption. By comparison, following a low energy-transfer wound, damage is usually confined to the wound track. The track often contains bone fragments and foreign bodies. Blunt. Rapid acceleration, deceleration or rotation incurred during blunt injury, results in diffuse or focal brain damage (1624). There may be pathological changes beneath the impact site (coup injury) or on the opposite side of the brain 386

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(contre-coup injury). This is especially likely if the mobile brain hits unyielding bone, such as the sphenoid ridge or the edge of the tentorium.

Secondary 1604 Secondary brain injury occurs as a result Preventing a rise of complications following the primary event. in ICP or a fall in cerebral perfusion This can usually be avoided by prompt recognition is essential to and appropriate treatment. preventing secondary injury Causes of secondary brain injury i.e., correct management of ABC. 1605 These include 1. Hypoxia.

2. Hypotension causing reduced cerebral Injuries to the brain perfusion. NB: the effects of hypoxia and and spinal cord hypotension are cumulative. following blast are usually caused by 3. Raised intracranial pressure. Intracranial secondary and pressure (ICP) - typically 10 mmHg - is the tertiary effects (0218). Cerebral air pressure inside the skull. Tissue oxygenation emboli may produce depends on the cerebral perfusion pressure neurological deficits. (CPP), which, in turn, is a product of mean arterial pressure (MAP - normally 70 to 90 mmHg) minus the ICP (CPP = MAP - ICP). If ICP rises, a higher blood pressure is needed to perfuse the brain. If CPP falls to <50 mmHg, cerebral hypoxia can follow. Anything that causes an increase in brain volume, such as haematoma or vasodilation, will lead to a rise in ICP. Hypoxia and raised CO2 levels cause cerebral blood vessels to dilate. This also happens following interference Altered with venous return (e.g., neck wound, tension consciousness is the hallmark of brain pneumothorax). injury. Drowsiness is often the first sign Swelling of the brain may lead to it being of raised ICP. displaced through the only available openings, Pupillary dilation is termed herniation or 'coning'. Compression a late feature. 387 Chapter_16.qxd 28/09/2004 15:57 Page 388 16: Head Injury

of the mid-brain at the tentorium causes drowsiness and unilateral limb weakness. It may also produce a third cranial nerve palsy manifested as pupillary dilatation - initially on the affected side. Damage to the motor or sensory cortex, or tracts leading from them, will result in a motor or sensory deficit on the opposite side to the injury. At the foramen magnum, compression of the medulla causes the pulse rate to fall, the blood pressure to rise and the respiratory rate to fall (the reverse of hypovolaemic shock). These features are known as Cushing's Response; they precede death and are an indication for immediate surgery. 4. Convulsions. These may be general e.g., a grand mal seizure, or focal. Convulsions can cause hypoxia, raised ICP and loss of consciousness. Prompt treatment is essential to prevent further brain damage. Penetrating brain injury is often associated with post- traumatic epilepsy (1640). 5. Infection. A dural tear causes leakage of CSF and enables ingress of organisms. Constant circulation of CSF aids spread of infection throughout the nervous system. Post-traumatic meningitis, abscess formation and osteomyelitis, carry a high morbidity and possible mortality. 6. Hyperthermia. Pyrexia, which is often fluctuating, may be due to primary or secondary injury to the heat regulating centre in the hypothalamus. The presence of local or systemic infection must be ruled out before making this diagnosis. Treatment is to cool the casualty whilst monitoring core temperature (2604).

388

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Role 1 1606 Steps include: • Obtain a history (MIST see 0301). The mechanism of injury will provide a clue Assume a cervical as to the degree of energy transfer. What was spine injury in brain function like immediately after injury for casualties who have suffered a significant example, was the casualty talking, was there blunt head injury; it a lucid interval? is uncommon after penetrating head • Primary survey. Assess and manage ABC injury (4%). (0302). Other life threatening injuries take precedence over head trauma. Give oxygen (0317) and maintain a normal BP. NB: this poses a dilemma in casualties requiring hypotensive resuscitation for non-compressible haemorrhage elsewhere (0333). • Assess AVPU (1610), and pupil size and reaction to light (1612). During the secondary survey, measure GCS (1614) and look for localising signs (1613).

• If there is a reduced level of consciousness, Hypovolaemic clear the mouth and pharynx, insert an airway shock in head injury and place the casualty into the three-quarter casualties is usually prone position. Where there is likelihood of due to blood loss from other organs. a cervical spine injury and circumstances Scalp trauma rarely allow, immobilise the C-spine combined with results in life the additional security of a spinal board (0318). threatening bleeding. • Dress scalp wounds. Bleeding can usually be controlled by a pad or by under-running with sutures. • Record details and arrange casualty transfer (1639).

389

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Triage of head injury casualties 1607 In ideal circumstances a. Severe head injuries need neurosurgical referral: • Coma score =8. • Open or depressed skull fracture. • A skull fracture with neurological signs. • Deteriorating GCS: a score that falls by 2, or more. • Development of localising signs. • (Significant intracranial haematoma on CT). b. Moderate head injuries (GCS 9-13) should be admitted for observation and CT scanning (if available): • Simple skull fracture. • Neurological signs, including confusion. • Casualties who are difficult to assess e.g., those affected by drugs or alcohol. c. Minor head injuries (GCS 14-15) following loss of consciousness need 24 hours (or until fully recovered) observation undertaken by designated personnel. These casualties are: • Fully orientated. • Have no skull fracture. • Have no neurological signs.

1608 In the less than ideal circumstances of the battlefield, the task is to identify those casualties who will benefit from transfer to a neurosurgical unit, versus those whose outlook is so poor they should not be put into the evacuation chain ahead of priority casualties. The head injury triage scheme (Figure 1602) is not foolproof but will act as a guide. 390

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Glasgow Coma Scale Score

More than 8 8 or less

with with or without Unequal Lateralising Unequal Lateralising pupils motor signs pupils motor signs

and/or Open/depressed fracture

and/or Basal skull fracture

and/or Foreign body penetration

and/or Epileptiform activity

and/or Hyperthermia

and/or Fall in GCS score

Transfer these as low Transfer all these urgently priority depending on as the situation allows casualty loading and tactical situation

Fig 1602 Head injury triage scheme.

Role 2, 3 and 4 1609 Steps include: Fluid resuscitation: • Re-triage and reasses ABCD. following head injury: cerebral perfusion • Look for: should be maintained with a • A reduction in GCS of 2 or more (1614), systolic BP>120. alteration in pupil size (1612), localising The dilemma in a casualty with signs (1613) or an increase in BP co-existing associated with a fall in pulse or respiratory non-compressible rate (1605). Such casualties require urgent haemorrhage is that assessment by a neurosurgeon. Continue you want to minimise bleeding by keeping to monitor regularly for 24-48 hours. the BP around • External signs - look for scalp swelling, 90mmHg. Do the best you can! abrasions, lacerations, fractures, exposed 391 Chapter_16.qxd 28/09/2004 15:57 Page 392 16: Head Injury

brain and foreign bodies. Adequate examination necessitates a head shave (1618). NB: it easy to miss a small, penetrating wound. • Features of a basal skull fracture (1636). • Epilepsy - describe the appearance of a seizure. • Radiological assessment: • If the history and examination suggest a penetrating injury or fracture, perform AP and lateral skull radiographs (NB: less important than regular observations). Look for fractures, intracranial air, foreign bodies, midline shift of a calcified pineal or fluid in the air sinuses - this may be blood and/or CSF. • Where available, a CT scan is the gold standard investigation. It is used to diagnose brain injury and guide the need for surgery. Look for intracranial bleeding, air or brain swelling. NB: to protect the airway during scanning, it may be safest to anaesthetise, intubate and ventilate the casualty. • Analgesia. Oral analgesia - codeine phosphate 30-60mg (0723) - may be sufficient. Do not withhold morphine if there is severe pain (0706)

Look for a cause for but remember, pinpoint pupils interfere with the casualty's neurological examination. Give small doses to convulsions e.g. avoid an increase in ICP by depressing • Hypovolaemic respiratory drive. shock. • Anoxia. • Prophylactic antibiotics. These should be • Hypercarbia. administered to all casualties with a suspected • Haematoma. open skull fracture or penetrating injury (0818). • Depressed • Anticonvulsants. Seizures should be stopped skull fracture. immediately using lorazepam 5mgs i.v. stat.; • Infection. diazepam is said to be less effective. Monitor 392 the airway and breathing during drug

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administration. If lorazepam is ineffective, give i.v. phenytoin, 1.5g over 30 minutes accompanied by ECG monitoring. Continued seizures are managed by mechanical ventilation and i.v. barbiturates. Prophylactic treatment is essential in 'at risk' casualties (1640); give phenytoin 300mgs orally at night. • Ventilate those with an airway or breathing problem and potentially survivable casualties 100ml of 10% with a GCS of =8 (coma). This may require mannitol i.v. over a surgical airway in the absence of anaesthetist. 30minutes may reduce cerebral Maintaining a normal PaO2 (typically 10KPa) oedema and buy and preventing a rise in PaCO2 (typically time. Steroids are 4-5KPa), will reduce the likelihood of cerebral of no value. oedema. Hyperventilation is no longer Lumbar puncture is generally recommended, but normocapnia is! contraindicated following head injury. • Nursing care. Unconscious casualties require bladder catheterisation, nasogastric tube suction to prevent aspiration (consider an orogastric tube following a basal skull fracture), fluids, maintenance of nutrition, physiotherapy, prevention of faecal impaction and two-hourly turning to prevent pressure sores. • Operative treatment. If a casualty requires neurosurgery, they should be transferred to an appropriate unit (1639). If facilities are not available and the casualty is deteriorating, it may be necessary to undertake life saving surgery. If there are other, more serious injuries, it is usually safe to delay treatment of open head wounds for up to 12 hours providing antibiotic cover is given. Avoid exploratory surgery without a clear indication. • Post head injury instructions. See 1638

Mini-neurological examination With progressive 1610 During the primary survey, neurological brain compression, first one pupil dilates deficit is rapidly assessed using AVPU and pupil then the other. 393 Chapter_16.qxd 28/09/2004 15:57 Page 394 16: Head Injury

Other causes of examination (1612). AVPU, is the casualty: coma include: • Diabetes. •Alert? • Epilepsy. • Responding to Voice? • Drugs/alcohol. • Stroke. • Only responding to Pain? • Meningitis. •Unresponsive? • Liver failure. • Heat/cold illness. 1611 In the secondary survey, the • Malaria. mini-neurological examination is carried out to: • Trypanosomiasis • Identify neurological injuries. • Establish an anatomical diagnosis. Changes in the casualty's • Determine severity. neurological condition can only be • Identify casualties needing early surgery. detected if the mini- neurological The mini-neurological examination assesses: examination is regularly repeated • Pupil function. and documented. If • Presence of localising signs. you detect a deterioration, act • Level of consciousness by the Glasgow upon it. Coma Scale. When applied repeatedly, the mini-neurological assessment can be used to objectively monitor neurological deterioration.

1612 Pupils. Are they equal and do they respond to light? A difference in diameter of >1 mm is abnormal Beware: this may be caused by local eye injury (1705). A bright light shone into the eye should cause rapid constriction of the pupil and a consensual response (1706). A sluggish response suggests brain injury; but, enlargement of the pupil, is a more important sign than failure to react to light. A dilated pupil on the side of the injury usually indicates ipsilateral brain compression.

1613 Localising signs. Obvious limb weakness 394 or loss of sensation localised to one side, suggests

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intracranial injury causing contralateral brain compression.

1614 Glasgow Coma Scale (GCS): This provides a quantitative and descriptive assessment of the GCS: do not simply give a total score, conscious level. It is the sum of scores awarded record individual for three types of response. (NB: These parameters findings descriptively are different in children). e.g.., 'eyes open to pain'. Scoring the GCS: • Eye opening (E). Document if the eyes cannot be examined due to injury and swelling. The standard painful stimulus is pressure over the supraorbital nerve. Spontaneous, i.e., open with normal blinking. 4 points Eye opening on request. 3 points Eye opening only to painful stimuli. 2 points No eye opening despite pain stimulation. 1 point

• Verbal response (V). Document if scoring is not possible because the casualty cannot speak (e.g., endotracheal intubation, neck injury). Orientated, spontaneous speech; knows name, age etc. 5 points Confused conversation but answers questions. 4 points Inappropriate words, i.e., garbled speech, but with recognisable words. 3 points Incomprehensible sounds or grunts. 2 points No verbal response. 1 point

• Motor response (M). The best response obtained for either arm is recorded, even though a worse response may be present in the legs. If the casualty is not able to move their limbs 395 Chapter_16.qxd 28/09/2004 15:57 Page 396 16: Head Injury

To correctly localise because of trauma or spinal injury, supraorbital pressure, the hand ask them to blink or stick their tongue out. must rise above the Obeys commands and level of the chin, otherwise this is a moves limbs when requested. 6 points flexion response. Localises pain i.e, moves upper limb in response to supraorbital compression. 5 points Withdraws limb from painful stimulus. 4 points Abnormal flexion - decorticate posture. 3 points Extensor response - decerebrate posture. 2 points No movement to any stimulus. 1 point

1615 A decrease in GCS of two points or more indicates deterioration. If this happens, exclude a problem with ABC, only then assume that changes are due to rising ICP. A fall of three points or more is a bad prognostic sign and requires immediate intervention. Dramatic changes in the Glasgow Coma Scale are often preceded by more subtle signs such as: • Onset or increase in severity of a headache. • Vomiting. • Fits. • Double or blurred vision. • Giddiness, mental confusion or drowsiness.

1616 Coma can be defined as that state in which: The unconscious casualty who has • There is no eye opening despite stimulus. been drinking or taking drugs has • The casualty does not follow commands. a head injury until proven otherwise. • There is no verbalisation. Consequently, a GCS that equates to coma is 8 or 396 less. The scale gives some indication of the severity Chapter_16.qxd 28/09/2004 15:57 Page 397 16: Head Injury

of brain injury as follows: Score 8 or less Severe Score 9 to 12 Moderate Score 13 to 15 Minor

1617 Common clinical situations after serious head injury are: Following long • Brief loss of consciousness with rapid recovery. bone fractures or • Unconsciousness, followed by gradual recovery. extensive soft tissue injury, fat embolism • Deeply unconscious with fixed, dilated pupils can cause loss of consciousness. and no response to stimuli. There may be other These casualties do not require immediate clinical signs (0982). Features of coning neurosurgical intervention; the first two groups are absent. recover, the third group die. By comparison, the following relatively uncommon situations may require intervention: • Unconscious, followed by improvement or a lucid interval, followed by further deterioration of consciousness. • Unconscious with a deteriorating GCS or localising signs. All casualties in a military • Conscious immediately after injury followed environment with by deterioration. a scalp wound should be considered to have Specific Head Injuries a penetrating brain injury until proven otherwise. Such Scalp lacerations injuries are easily missed - it is safest 1618 The scalp tends to bleed profusely. to perform a wide or Unless lacerations are treated properly they complete head can lead to infection and skin defects. shave in all those with blood in their • Management is to clean and shave the scalp hair. This will also and remove hairs with adhesive tape. reduce contamination, • Use local anaesthetic (0728). Keep wound but takes time. 397 Chapter_16.qxd 28/09/2004 15:57 Page 398 16: Head Injury

A

B

C

Fig 1603 Managing a scalp wound. A) Minimal wound excision. Pressure on either side of the wound aids haemostasis. B) Where necessary, elevate the pericranium to inspect the skull. C) Close with deep mattress sutures to include the galea aponeurotica or suture in two layers.

excision to a minimum otherwise closure may be difficult (Figure 1603). Because of the excellent blood supply, primary wound closure is allowed, unless this is prevented by tissue loss (0504). • Pressure applied on either side the wound will 398 usually control bleeding.

Wound Management: see Chapter 5 Chapter_16.qxd 28/09/2004 15:57 Page 399 16: Head Injury

A

B

C

Fig 1604 Closure of large scalp defects. A) Making an 'S'-shaped incision reduces tension and may permit closure. B) Rotation flap. C) Transposition flap.

• Suture the scalp using deep mattress sutures to include the galea (Figure 1603). Do not leave bare bone exposed. • Extensive skin loss may be treated with a split skin graft as long as underlying pericranium is present. Alternatively, denuded bone may require a skin flap (Figure 1604). 399

Surgical Handicraft: see Chapter 30 Chapter_16.qxd 28/09/2004 15:57 Page 400 16: Head Injury Penetrating brain injuries Probing wounds to diagnose a Clinical features penetrating injury or fracture is 1619 These include: contentious! Do not use an instrument; • The diagnosis may be obvious in a casualty it may cause further with a single or multiple scalp lacerations. injury. If necessary, Conversely, a fragment entering the eye, orbit use a gloved finger gently but, better to or roof of mouth and going on to penetrate the miss a fracture than brain, is often missed during initial assessment. make it worse! • Casualties who are in deep coma (GCS 3-5) have a near 100% mortality rate (Table 1601).

Level of Consciousness Percentage Mortality Approximates to: Alert 11.5 A Drowsy 33.3 V Reaction to pain 79.1 P Coma 100 U

Table 1601 Mortality rates following penetrating head injuries.

• Through-and-through wounds and injuries to the brain stem are nearly always fatal. By comparison, an open brain injury in a conscious casualty carries a good prognosis if surgery is not delayed.

Management 1620 X-rays in two planes will show metallic If the casualty continues to have fragments, a skull defect and bone fragments within a GCS of = 5 after the intracranial cavity. A CT scan will demonstrate resuscitation for a the missile track and the fragments. penetrating head injury, treatment In general, missile injuries merit formal surgical is futile. exploration. But, the nature of the injury and the casualty's condition may mean they are a low priority for transfer and only supportive measures are appropriate (1607). 1621 Operative treatment.

400 • The best operating conditions are achieved by Chapter_16.qxd 28/09/2004 15:57 Page 401 16: Head Injury

Dressing towel

Head ring

Fig 1605 Positioning and draping the head prior to neurosurgery.

having an anaesthetised, paralysed and Excision of the wound track is ventilated casualty. Control of arterial CO2 difficult. Having and O2 and prevention of coughing and straining, exposed the optimises operating conditions and minimises defect in the dura, bleeding. Local infiltration with lignocaine plus a decision has to adrenaline will aid haemostasis and, because be made whether to proceed. If in there are no pain receptors in the brain, may doubt, close the be sufficient for simple procedures. wound and refer to a neurosurgical unit. • Perform a complete head shave to allow for more than one incision to be made. Tilt the operating table so that the head is 20 to 30 degrees above the heart (NB: too high risks air embolism). Stabilise the head with the site of injury uppermost. Where possible, position with the vault projecting over the end of the

operating table to allow access to all areas Dead tissue and (Figure 1605). Clean the skin and apply contamination may sterile drapes. lead to abscess formation. Metallic • The minimum instruments required are fragments do not illustrated in Figure 1606. Extend the scalp generally cause late defect, preferably in a vertical direction but, problems and should only be retrieved if do not turn a soft-tissue flap. Scalp bleeding easily accessible. is controlled by firm pressure near the skin Pieces of bone are edge followed by application of forceps to the more likely to cause galeal edge at 1cm intervals (Figure 1607). infection and should ideally, be removed. Insert a self-retaining retractor. 401

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Brace

Perforator burr

Conical burr

Bone nibbler

Fine suction

Dural elevator

Malleable retractor

Self retaining retractors

Fig 1606 Essential neurosurgical instruments.

• Strip the periosteum back for 2cm around the defect. Perform a small craniectomy (approximately 4cm diameter) using bone nibblers with the missile hole as a starting point. 402 Strip off underlying dura as the opening enlarges. Chapter_16.qxd 28/09/2004 15:57 Page 403 16: Head Injury

Fig 1607 Controlling haemorrhage using artery forceps applied to the galea aponeurotica. Enlarging a penetrating head injury using nibblers.

• Keep the wound moist with normal saline. Explore the direction of the track with a sterile probe. Aspirate the missile-track using low pressure suction (Figure 1608). Dead brain sucks easily. Remove all non-viable tissue, bone fragments and foreign bodies. Do not probe with your finger, this will push foreign material more deeply into the wound. Irrigate the resultant cylindrical hole with normal saline. Essential aids to exploration are a headlamp and a narrow, malleable retractor. • Haemorrhage may be severe, especially from a dural venous sinus and cannot be managed Applying haemostats or attempting to by pressure. Control arterial bleeding with suture a bleeding diathermy - bipolar set on low power is venous sinus preferred, a fine suture passed under the usually makes vessel or Ligaclips™. Every bleeding point matters worse. must be controlled. Several minutes of light pressure using a wet pattie over a piece of gelatine sponge, Oxycel™ or crushed muscle (e.g., temporalis), should stem most venous 403 Chapter_16.qxd 28/09/2004 15:57 Page 404 16: Head Injury

Fig 1608 Aspiration of a penetrating brain injury.

bleeding. Use bone wax to control bleeding from the edge of the skull. • Uncontrollable bleeding is probably from the sagittal sinus or from deep inside the brain and has a poor prognosis. It may be impossible to locate or control. Gently insert a moist, ribbon gauze tampon for 10-15 minutes. If bleeding continues after stepwise removal of the tampon, leave it in place for 24 hours. • Expose and excise the dural defect. If it cannot be closed, trim the edges and patch the defect with an adjacent piece of pericranium (Figure 1609A). Options for larger defects include use of temporalis fascia or fascia lata from the thigh. Ensure there is no CSF leakage. • Replace clean skull fragments (Figure 1609B). Large bone defects can always be repaired later. If there is continued extradural bleeding, insert a suction drain. Close the skin in two layers. Sutures are removed at 5-7 days. • Apply a light dressing. Keep the head elevated by nursing the casualty on several pillows. Continue antibiotics, anticonvulsants and mobilise the casualty. 404 Chapter_16.qxd 28/09/2004 15:57 Page 405 16: Head Injury

Dura

Scalp

Bone

Patch

A

B

Fig 1609 A) Patching a defect in the dura. B) Replacing clean bone fragments.

Protruding foreign bodies 1622 Ideally, all objects protruding from the skull should be left in place, immobilised and the casualty transferred to a neurosurgical unit for angiography and surgery. Removal may lead to torrential and uncontrollable haemorrhage. This has to be balanced with the risk of further injury from leaving the object in-situ during a difficult and prolonged transfer.

Blunt head injuries 1623 Casualties who have suffered blunt head injury are usually asymptomatic or have mild concussion. With increasing severity of injury, there 405 Chapter_16.qxd 28/09/2004 15:57 Page 406 16: Head Injury

may be diffuse or focal structural changes in the brain, producing altered consciousness and localising signs.

1. Diffuse brain injury 1624 Shearing forces caused by rapid head motion (1603) can cause widespread damage within the brain substance. Such injuries form a spectrum from mild concussion - no structural changes - to diffuse axonal injury: • Concussion. Clinically, there is brief loss of consciousness and temporary confusion or amnesia. The severity and duration of symptoms are proportional to the magnitude of the injury. Associated features include: headache, dizziness or nausea. Localising signs are absent. • Diffuse axonal injuries. Prolonged coma is present in 44% of cases. The overall mortality rate ranges from 30 to 50%. Treatment involves controlled ventilation. Because the mortality is so high, these casualties have a low priority for treatment resources and transfer. • Traumatic subarachnoid haemorrhage may accompany severe, diffuse brain injury. The irritant effect of the bloody cerebrospinal fluid in the subarachnoid space causes headache, photophobia and neck stiffness. On its own, subarachnoid haemorrhage is not serious, but prognosis is poor if associated with brain injury.

2. Focal brain injuries 1625 Haemorrhage may arise from meningeal vessels or from vessels within the brain substance. Correct diagnosis and rapid transfer for surgery, reduces morbidity and mortality. The spectrum of focal brain injury ranges from: 406 Chapter_16.qxd 28/09/2004 15:57 Page 407 16: Head Injury

• Contusion. This may be coup or contre-coup (1603). If the contusion occurs near the sensory or motor areas of the brain, casualties present with varying degrees of neurological deficit. Coma is more likely to be due to contusion than clot. Precise diagnosis requires CT scanning. • Extradural haematoma (1627). • Subdural haematoma (1630). • Subarachnoid haemorrhage (1624). • Intracerebral laceration. Intracerebral clots cause raised intracranial pressure. The majority resolve spontaneously. Large ones require neurosurgical evacuation if there is clinical deterioration.

Management of blunt head injury 1626 Most blunt head injuries do not require surgery and are managed as in 1609. The majority make a good recovery. Operative treatment may be required to relieve pressure from an extradural or subdural haematoma, elevate a depressed skull fracture or seal a CSF leak.

Extradural haematoma (EDH)

Clinical features If you operate and fail to find 1627 These include: a blood clot, you are unlikely to have • They are uncommon, accounting for <1% done any harm. of trauma-related coma. • EDH classically follows a fracture of the temporal bone, damage to the middle meningeal artery and arterial bleeding into the space between the skull and the dura (Figure 1610). As the haematoma expands, it strips the dura from the inside of the skull. This in turn, leads to brain compression and, if not rapidly treated, death of the casualty. 407 Chapter_16.qxd 28/09/2004 15:57 Page 408 16: Head Injury

Extradural haematoma

Torn middle meningeal artery

Temporal fracture

Oculomotor Edge of nerve tentorium compression cerebelli

Fig 1610 Extradural haematoma causing oculomotor (third) nerve compression and ipsilateral dilatation of the pupil. Note the more localised nature of the haematoma compared to SDH (Fig 1613).

It is usually difficult • On examination, there may be boggy swelling to differentiate in front of the ear. This is due to blood forcing between an its way through the fracture line to form extra- and a temporalis haematoma. a subdural haematoma on • Following injury, in a classic case, there symptoms alone. is loss of consciousness followed by some improvement, or a lucid interval lasting several hours, (it can be up to a week). With increasing brain compression, there is secondary loss of consciousness, contralateral limb weakness and ipsilateral dilatation of the pupil. NB: the lucid interval may be absent.

Investigation 1628 Skull radiographs usually demonstrate a fracture. On CT scan, there is a localised, well defined opacity. By comparison, a subdural haematoma is more diffuse.

Operative treatment 1629 If the casualty with suspected EDH is deteriorating (1609), perform an urgent burr hole and craniectomy, even if sophisticated investigations 408 are available. Chapter_16.qxd 28/09/2004 15:57 Page 409 16: Head Injury

Superior sagital sinus Craniotomy

Transverse sinus

Fig 1611 Site of burr holes. These can be joined to perform a craniotomy.

• Prepare the casualty as in 1621. If you suspect a subdural or • Position burr holes over the site of injury on extradural the same side as the dilated pupil (Figure 1611). haematoma in This will be correct in 85% of extradural and a casualty whose many subdural haematomas. If both pupils respiratory rate is slowing, do not wait are dilated, start on the side where dilation for investigations, was first noticed. Avoid making burr holes proceed to burr hole within 2cm of a dural sinus or over loose and craniectomy. or depressed bone fragments. This is rapid, simple and life saving. • Make a 4-5cm vertical incision down to bone (Figure 1612). For the temporal burr hole, make an incision 1cm in front of the ear, centred 2cm above the zygoma. (NB: a common mistake is to make it too high). Incise the temporalis fascia and split the temporal muscle. • Perform a burr hole in the centre of the incision, Performing burr first using the brace and sharp perforator. holes in a casualty When you start to see dura, widen the hole with a respiratory with increasing sizes of burr. Applying too much rate < 6 is likely pressure will easily result in laceration of the to be futile. cortex. Do not open the dura, but gently push it away with an elevator. Nibble the skull to widen the defect. A common error is not to make the craniectomy large enough. 409 C D E F A B Fig 1612A) Incision. of performing a temporal burr hole. The temporalis muscle is divided to expose bone. Use artery forceps Technique B) and a self-retaining retractor to improve exposure and control bleeding. then a conical burr. C) Make the burr hole first with a perforator, D) Separating dura from skull. E) Enlarging the burr hole using nibblers. F) Controlling bleeding by placing a ligature under the vessel.

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• Aspirate as much haematoma as possible. If, on making the Identify and control the bleeding point (1621). temporal burr hole Leave the burr hole and craniectomy open there is brisk arterial and close the scalp in layers over a vacuum bleeding, there is drain. Leave the drain for at least 24 hours. probably iatrogenic injury to the middle Start anticonvulsants (1609) and mobilise meningeal artery. the casualty. Most make a good recovery. Locate and control with diathermy. • If haemostasis is difficult and you have neurosurgical experience, perform a craniotomy ("trauma flap"). Make additional burr holes as in Figure 1611 and divide between them using a Gigli saw. Alternatively, simply leave the original burr hole open with a vacuum drain, close the scalp in layers and transfer the casualty to a neurosurgical unit. • If the first exploration is "dry": 1 Gently probe between the skull and dura in all directions. 2 If the dura is blue and bulging, suspect a subdural haematoma and incise the dura. 3 Make additional burr holes at the positions indicated in Figure 1611. 4 Make burr holes on the opposite side.

Subdural haematoma (SDH) Clinical features 1630 These include: • They occur in up to 30% of serious head injuries and can be bilateral. • A blow to the head, particularly to the fronto- temporal region opposite the sphenoid ridge, results in cortical laceration and tearing of the bridging veins between the cortex and the dura. Bleeding occurs in the subdural space and spreads slowly over the whole of the affected hemisphere (Figure 1613). SDH are typically 411 Chapter_16.qxd 28/09/2004 15:57 Page 412 16: Head Injury

Subdural

Fracture

Lacerated/ contused brain

Compressed oculomotor nerve

Contre-coup injury

Fig 1613 Subdural haematoma. Note the spread of the haematoma over the hemisphere and the underlying cerebral laceration. There is a contrecoup injury and early coning.

seen after road traffic accidents and falls. The casualty frequently presents in a coma and deteriorates over the next 6-12 hours. There may be accompanying focal signs. • Because of associated injury to the underlying brain tissue, mortality is as high as 60%

Investigation 1631 CT scan shows a diffuse, subdural clot, often extending over the whole hemisphere (Figure 1613).

Operative treatment 1632 Optimum treatment involves an extensive craniectomy starting in the temporal region and opening the dura widely (1629). This requires neurosurgical experience. • In an emergency, the inexperienced surgeon may do some good by performing burr holes starting in the temporal region (Figure 1611). • Open the dura sufficiently to allow evacuation 412 of some clot and insertion of a suction drain. Chapter_16.qxd 28/09/2004 15:57 Page 413 16: Head Injury

This may enable transfer to a neurosurgical unit for further care. In military casualties, start antibiotics and anticonvulsant treatment (1609).

Skull fracture Closed skull fracture 1633 This is common and usually uncomplicated. The significance of a skull fracture is that it identifies a casualty with a higher probability of having or developing an intracranial haematoma. For example, the presence of a skull fracture, together with a period of loss of consciousness, carries a 1:4 Brain injury frequently occurs risk of intracranial bleeding. All casualties with skull in the absence of fractures should be detained for observation. a skull fracture. Similarly, most skull Open linear skull fracture fractures are not associated with 1634 Most of these can be left alone. severe brain injury. • Remove dirt and contaminated periosteum. • If there is leakage of CSF, this can usually be controlled by plugging with a piece of crushed temporalis muscle or careful, layered closure of the scalp wound. • Where the fracture crosses the line of intracranial vessels e.g., middle meningeal artery (1627), be aware of possible haematoma formation.

Open depressed skull fracture 1635 By definition, there is a tear in the dura allowing communication with the brain. Because of Be wary of fractures the energy required to shatter the adult skull, most overlying dural open skull fractures are associated with depressed venous sinuses. bone fragments. The diagnosis may be obvious. Haemorrhage can be torrential and life Alternatively, skull radiographs, including tangential threatening. views, or a CT scan, may be necessary. In order to reduce infection and late complications (1640), treatment is to explore, preferably under general anaesthetic (1621). 413 Chapter_16.qxd 28/09/2004 15:57 Page 414 16: Head Injury

Only replace • Administer antibiotics (0818). fragments if these are uncontaminated. • Extend the skin laceration using a vertical curved Skull defects incision in line with the scalp arteries. Scrape off can readily be replaced in a the periosteum. Enlarge the fracture site using neurosurgical bone nibblers (Figure 1607). unit. • If the dura appears intact, it is generally safer to leave the depressed fragments alone and transfer the casualty. The bone fragments may be jammed together; careless manipulation of them can cause serious bleeding. Otherwise, remove the fragments and repair or patch the torn dura (1621). • If the fracture is close to a venous sinus, it is wisest to leave it alone and refer to a neurosurgeon. • Replace uncontaminated bone fragments; suture large fragments to the pericranium. Close the skin in two layers with a vacuum drain. Prescribe anticonvulsants if the dura has been torn.

Basal skull fractures 1636 The base of the skull runs diagonally backwards and downwards; fractures produce signs anywhere along this line (Figure 1614). Points to note: • A subconjunctival haematoma may occur following a fracture of the roof of the orbit as well as a base of skull fracture. When examined, there is no posterior limit to the haematoma whatever the eye position. Lesser degrees of this finding are likely to be due to local eye trauma. • Bilateral periorbital haematomas (racoon eyes) are associated with fractures through the cribriform plate. • Bruising over the mastoid process (Battle's sign) 414 usually takes 12-36 hours to develop.

Antibiotics: see Chapter 8 Chapter_16.qxd 28/09/2004 15:57 Page 415 16: Head Injury

Bilateral periorbital bruising (racoon eyes) Subconjunctival haematoma Haemotympanum

Level of base of skull

Rhinorrhoea Otorrhoea Mastoid bruising (Battle’s sign)

Fig 1614 Position of skull base. Signs of a basal skull fracture can occur anywhere along this oblique line.

• Basal skull fractures are difficult to diagnose on plain radiographs. Look for the presence of intracranial air or blood in adjacent air sinuses. Confirmation requires a CT scan. The importance of a base of skull fracture is that it can be associated with intra-cranial injury and long term morbidity.

CSF leak 1637 Leakage of CSF occurs in casualties with an open, depressed skull fracture or penetrating brain injury. CSF leaking from the nose (rhinorrhoea) or ears (otorrhoea) is diagnostic of a tear in the thin dura at these sites. These are features of a basal skull fracture (1636). • When CSF is mixed with blood it may be difficult to detect. A simple test is to place a drop of suspect blood onto a white gauze swab and look for the appearance of a pink halo (ring sign). 415

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• Because close observation is not possible under field conditions, give prophylactic antibiotics (0818). • Leakage, especially from the ear, usually stops within a few days. Occasionally, leakage from the nose persists; warn casualties not to blow their nose. Seek neurosurgical advice.

Further Management

1638 Good nursing is more likely to save lives and prevent complications than neurosurgery. • Following recovery from a severe head injury, the casualty is returned to the UK for further treatment and rehabilitation in a specialist unit. • After lesser degrees of head injury, they should not be allowed to fight or operate machinery until they have made a full recovery. • Warn them to seek medical advice if they develop headaches or other neurological symptoms.

Transfer of head injuries 1639 Most casualties transferred following head injury will be sent to a neurosurgical unit. Casualties travel well, even if ventilated, provided they are fully resuscitated and stabilised. One risk of air transportation is expansion of intracranial air at altitude (2919). • Casualties should be carried at a low altitude or the cabin pressurised to that of sea level. • Transfer should be in a head-up position (20-30 degrees) to improve venous drainage and reduce ICP. This is important to remember when moving casualties by helicopter - most of them fly in a nose-down attitude.

416

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Long term complications 1640 Specific complications include: • Epilepsy. Injuries carrying a high incidence include: • Secondary brain abscess (50%). • Penetrating missile wounds of the brain (40%). • Acute extradural and subdural haematomas (30%). • Early epilepsy - fits occurring in the first week (30%). • Open, depressed skull fracture with a dural tear (25%). • Brain abscess. • Persistent CSF leak. • Hydrocephalus.

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Ophthalmic Injury

Introduction

1701 Approximately 10% of all battle casualties Only 25% of eye sustain eye trauma. Fifty percent of these are injuries can return penetrating wounds of the globe; 15% are bilateral to active duty, injuries. Corneal abrasions, corneal foreign bodies compared with 85% of all surviving and conjunctival lacerations are common and wounded. incapacitating. If the casualty has multiple injuries or is unconscious, ophthalmic injuries are easily missed and may result in blindness. In 15% of eye injuries there are associated injuries to the cranium and brain.

Anatomy

1702 See Figures 1701 and 1702.

History

Previous ophthalmic history

1703 Points include: Consider occult eye or brain injury • Acuity. Did the affected eye see normally in all casualties. before the injury? Always examine the eyes during the • Amblyopia. Is the injured (or uninjured) eye secondary survey. amblyopic (lazy)? • Allergies. For example, any antibiotic sensitivity? • Aid. What first aid has the casualty received? • Admissions. Any previous eye operations or injuries? 419 Chapter_17.qxd 28/09/2004 15:57 Page 420 17: Opthalmic injury

Vitreous Ciliary body Optic disc Suspensory Optic ligament nerve Iris Cornea Macula lutea Choroid Anterior Sclera chamber Retina Posterior chamber Conjunctiva

Fig 1701 Parts of the eye.

Details of injury

Take a detailed 1704 Find out about: history of the mechanism • Activity and circumstances of injury e.g., of injury. hammering, munition blast, laser strike? • Blunt or sharp trauma? • Chemical injury: was it acid, alkali or a chemical agent attack (nerve agent - pinpoint pupils 0232; blister agent -irritation 0243)? • Eye drops. Is the casualty on eye medication or have they received miotics (constrict the pupil) or mydriatics (dilate the pupil and paralyse the ciliary muscle)? • Eyewear at the time of injury e.g., glasses, protective eyewear or contact lenses? • Foreign body? Examine a sample if available.

Examination and Treatment

Always record the 1705 Check visual acuity and perform a visual acuity. Initial acuity is the single systematic examination of the eye: most important predictor of final 1. Acuity should be recorded as the best corrected visual outcome. vision. This is measured by asking the casualty to read a standard reading chart (Snellen’s chart) 420 Chapter_17.qxd 28/09/2004 15:57 Page 421 17: Opthalmic injury

Frontal sinus Superior oblique muscle Superior rectus muscle Medial rectus muscle Optic nerve Lateral rectus muscle (cut)

Inferior rectus muscle Inferior oblique muscle Infraorbital nerve Maxillary sinus

Fig 1702 Muscular attachments of the eye.

at 6 metres. The acuity is recorded as a fraction, the casualty's distance from the chart is the numerator and the line achieved on the chart in the denominator (e.g., can see the fifth line down but not the sixth = 6/5). A Pin hole occluder can correct most refractive errors if the casualty's glasses are not available. The eyes are tested one at a time with the other eye carefully occluded. If a Snellen's chart is unavailable, acuity should be recorded as follows: • Able to read normal text or only headlines. • Count fingers. • Hand movements. • Perception of light or no perception of light. 2. Systematic examination of the eye and orbit: 1. Check for a relative afferent pupil defect. 2. Assess for facial and lid injury. 3. Examine the anterior and posterior segments of the globe. These will now be discussed in more detail.

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A

B

Fig 1703 A) Fracture of the orbital floor causing enopthalmos and muscle entrapment. B) Zygomatic fracture causing deformity of the orbital rim and reduced jaw movement.

The swinging torch test is the most 1. Check for a relative afferent pupil defect important objective (RAPD) test in ophthalmology. If a bright light is The swinging torch test used, this test can be carried out even 1706 This assesses the direct and consensual when one lid reflexes of each pupil and hence, their relative is closed. sensitivity to light. Shine a bright light into the first 422 pupil for 2 seconds and then the other pupil for a Chapter_17.qxd 28/09/2004 15:57 Page 423 17: Opthalmic injury

Fig 1704 An inferiorly displaced right lateral canthus and displaced pupil indicates a zygomatic fracture.

similar period, taking 1 second to swing across. This cycle is repeated several times. Both pupils should be the same size and constrict equally to light. If there is dilation, then that eye has damaged retinal or optic nerve function and a poor visual prognosis i.e., it has a RAPD. NB: Drugs used in the field can affect pupil size and reactivity e.g., the Combopen contains atropine - overdoseage causes dilation of the pupil (0237).

2. Assess for facial and lid injury Orbits. 1707 Examination:

• Look for mal-occlusion or limitation of jaw Injury to the optic movement (Figure 1703), swelling, asymmetry nerve is common or flattening of the cheeks (malar fracture?). in head and orbit trauma. In certain • Horizontal alignment. Assess this using a cases, high dose straight edge or ruler. Each pupil should be an steroids are of equal horizontal distance from the bridge of the benefit if given early (1822). nose and horizontally aligned with the canthi. An inferiorly displaced lateral canthus indicates a zygomatic fracture (Figure 1704). • Enophthalmos - a depressed eye, suggests an orbital blow out fracture, (Figure 1703) while proptosis - bulging eye, suggests a haematoma. Gently palpate over the upper lid. A tense orbit with reduced visual acuity indicates a severe orbital haemorrhage. This is a sight-threatening 423

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problem requiring immediate surgical decompression (1822). • Diplopia (double vision) and restriction of eye movements indicates injury to cranial nerves or muscle entrapment, (Figure 1703). • Infraorbital hypoaesthesia indicates involvement of the infra-orbital nerve in a blow-out fracture of the orbital floor, (Figure 1702). • Palpate the orbital rim for steps and crepitus, that indicate fracture of the orbital rim or damage to an air sinus.

1708 Intra-orbital foreign bodies. In the field these are best left undisturbed. • General measures for dealing with eye injuries are summarised in Table 1701. • Large, protruding foreign bodies should be stabilised. Further investigations that will be needed include: facial radiographs and ultrasound or CT scanning. Administer prophylactic antibiotics (Table 1702) and transfer the casualty as a stretcher case to an ophthalmic unit.

• Systemic antibiotics and antitetanus.

• Treat as a stretcher case.

• Analgesics and antiemetics.

• Topical antibiotics. Administer every 1-2 hrs with an initial loading dose (one drop every minute for 5 minutes). Because ointment may enter the globe through even small wounds, use drops if there is any possibility of perforation.

• Shield not pad. Padding the eye may extrude ocular contents or promote infection. It is better to leave the eye open and protect it with a shield (1713).

424 Table 1701 General measures (STATS) for dealing with eye injuries.

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• Orbital haemorrhage and infection pose a threat to vision from pressure effects; drain the former and give i.v. antibiotics (Table 1702) for the latter.

G Amethocaine, G Benoxinate topical anaesthetic as required G Fluorescein dye to highlight corneal abrasions Oc Lacri-Lube lubricant as required (Oc chloramphenicol commonly used in field) G Cyclopentolate or dilates the pupil and paralyses G homatropine the ciliary muscle (act for 2 days), G atropine (acts for 2 wks) G or Oc chloramphenicol, topical antibiotics (see Table 1701) Ofloxacin G Maxidex topical steroid preparation 4-6 hourly Ciprofloxacin (oral 0820), antibiotics that enter the eye azithromycin (500mg once daily orally) Co-amoxyclav (i.v. 0817; antibiotics for sinus fractures oral 0821), ceftriaxone + metronidazole (0818) G Timolol (twice daily) Treatment of glaucoma or acetazolamide (oral four times daily)

Oc = ointment G = drops Topical preparations contain preservatives which are toxic if they enter the eye - avoid if you suspect a penetrating injury.

Table 1702 Useful ophthalmic preparations.

1709 Orbital fractures. When faced with a lid injury, always Management is not urgent. consider penetration • Where suspected, give systemic antibiotics of underlying structures: (Table 1702) and instruct the casualty not to • Eye blow their nose. Transfer. • Sinus • Investigate with plain facial radiographs and • Brain CT scanning. 425 Chapter_17.qxd 28/09/2004 15:57 Page 426 17: Opthalmic injury

• Injuries may require reduction and fixation (1823-1824).

Lids 1710 Examine the lid contours

Conjunctival swelling Asymmetry can be caused by ruptured canthal is common in lid tendons; these attach the medial and lateral ends of injuries, and may the lids to the orbit. A flattened upper lid may mean hide a penetrating injury of the globe. the globe is perforated.

1711 Search for foreign bodies Evert the upper lid (Figure 1705). NB: do not do this if globe penetration is suspected. Consider doing a plain radiograph - a small wound can hide a large foreign body.

1712 Lid wounds Assess: • Depth of injury - full or partial thickness. • Tissue loss. This may lead to corneal exposure. • Site. Lacerations medial to the puncta may involve the lachrymal drainage apparatus • Contamination. Clean dirty wounds and explore them to exclude a foreign body. • Levator function. Ptosis and inability to open the eye, suggest levator muscle involvement.

1713 Management of lid lacerations: • The lids have an excellent blood supply, so extensive wound excision should be avoided. • Superficial lacerations not involving lid margins and with good levator function, may be repaired with 6/0 Prolene. • Full thickness injuries and those involving the 426 levator muscle, may require complex alignment Chapter_17.qxd 28/09/2004 15:57 Page 427 17: Opthalmic injury

Fig 1705 Technique of everting the upper eye lid and foreign body removal.

and should ideally be repaired by an ophthalmologist. • Stop active bleeding. If necessary, use several tacking sutures to hold wound edges together. Avoid pressure on the globe in case there is an undetected perforation. 427

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Distorted Pupil: Deep laceration Beware of orbit: penetrating Beware of injury penetrating eye and head injury Basal tear of iris and retained foreign bodies

Subconjunctival haemorrhage: If it tracks posteriorly beware of Marginal orbital and base laceration of skull fracture Penetrating Hyphaema eye injury

Fig 1706 Injuries of the eye.

• Before transfer, instil ocular lubricants (Table 1702, NB: avoid them if there is a suspicion of globe perforation) and protect the eye with a perforated Cartella shield. Alternatively, a shield can be improvised from the base of a polystyrene cup or gallipot. If there is lid avulsion, 'cling film' held in place by the shield can be used to prevent corneal desiccation.

1714 Lid burns Approximately 5 to 10% of all burn casualties suffer damage to their eye lids. Principles of management are the same as for burns elsewhere. Lubricants should be used liberally. Topical antibiotics (Table 1702) are given for corneal epithelial defects or conjunctivitis. Initially, lid tissue swelling may protect the globe, but subsequent sloughing and contracture can lead to corneal exposure. Immediate care of the eye - prevent exposure - and ophthalmic intervention 2 or 3 days later - desloughing or excision of eschar - can improve visual outcome.

428

Burns: see Chapter 22 Chapter_17.qxd 28/09/2004 15:57 Page 429 17: Opthalmic injury 3. Examine the anterior and posterior To examine the segments of the globe globe, the lids General should be held open by pressure against the orbital margins. 1715 Globe injury Do not press on a possibly penetrated Serious signs are: globe. Be very gentle. • Prolapse or expulsion of lens, iris, vitreous, choroid or retina. • Associated hyphaema (Figure 1706).

1716 Occult signs of globe rupture following blunt

or penetrating injury include: All injuries should be • Soft eye. assumed to have a retained intra-ocular • Total hyphaema. or orbital foreign body. Always • Abnormally deep anterior chamber. consider a plain radiograph, CT • Restriction of eye movement. scan or ultrasound. • Chemosis (swelling of the conjunctiva). • Subconjunctival haemorrhage (1636).

1717 Management of globe rupture or Do not manipulate penetrating injury any instruments This is an emergency: inside the globe. Do not suture • Do not apply topical medication. the iris. • Cover with a protective eye shield (1713). Do not use an eye pad as any pressure can cause ocular contents to extrude. • Nurse the casualty sitting up. • Give systemic antibiotics, an anti-emetic, pain relief and a tetanus booster. • The casualty requires urgent transfer to an ophthalmologist for surgical repair within 48 hours. If transferred by air, keep the cabin 429

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pressure to that at sea level. The inexperienced surgeon is likely to do more harm than good. The use of 'super glue' tends to interfere with subsequent repair- 'bio-glue' may soon be available. • At Role 3 or 4, protruding tissue from inside the eye is cut level with the cornea or sclera. The cornea and sclera are closed using interrupted, non-absorbable monofilament 9/0 sutures. Sutures must not be too superficial or they will tear out, yet should not cross the inner layer (the cornea is only 1-2mm thick). Large conjunctival lacerations require closure with 6/0 absorbable suture.

Anterior chamber 1718 Assess chamber depth by Illuminating from the side with a focusing torch.

1719 Hyphaema. The presence of blood in the anterior chamber is usually associated with blunt trauma (Figure 1706). Even a small hyphaema may rebleed. The rebleed is usually more serious than the primary bleed, leading to high intra-ocular pressure and corneal blood-staining (NB: exclude a ruptured globe, 1716). The casualty is often drowsy or restless and may feel nauseous. Serious signs are: • Total hyphaema filling the anterior chamber, especially if this is black, implying anoxia due to high pressure and stagnant aqueous circulation. • Deteriorating vision or complete loss of vision. • Afferent pupil defect (RAPD), indicating optic nerve or retinal damage (1706). • A rebleed. • Increasing pain. 430 Chapter_17.qxd 28/09/2004 15:57 Page 431 17: Opthalmic injury

1720 Treatment of hyphaema • Bed rest for 4 or 5 days with the head slightly raised to allow blood to settle out of the visual axis. • Analgesics and antiemetics; avoid aspirin because of its antiplatelet action. • Dilate the pupil with homatropine or atropine (Table 1702). • Treat any associated corneal abrasion (1726). If there is no abrasion, then do not pad the eye. • Instil topical steroid drops (Table 1702). • If intraocular pressure is raised, use oral and/or topical glaucoma medication; NB: not pilocarpine - constricts the pupil and increases iris vessel leakage.

Pupil 1721 Assess shape, symmetry and reactions directly and against the red reflex (1723) The iris should be flat and the pupil central and round. If either is distorted, this suggests one or more of the following: • Anterior segment trauma. • Iris plugging a hole in the cornea. • Vitreous prolapsed into the anterior chamber. The presence of a hyphaema indicates significant injury and the need for urgent transfer to an ophthalmologist. Transillumination defects in the iris are due to tears or passage of a foreign body. Also look for dialysis (disinsertion of the iris root) and notching of the pupil margin.

Lens 1722 Examine this using a direct ophthalmoscope 431 Chapter_17.qxd 28/09/2004 15:57 Page 432 17: Opthalmic injury

with a +10 or +15D lens dialled up. Look for: • Partial or total dislocation into the anterior compartment or vitreous. • A tract made by the passage of a small foreign body (seen against the red reflex). • Traumatic anterior or posterior subcapsular cataract may be seen at an early stage - after 3-4 days. • If the len's capsule is ruptured, flocculent lens matter may be visualised in the anterior chamber or vitreous.

Red reflex

Do a red reflex test 1723 Dim the room illumination. Using an on every casualty. ophthalmoscope with a 0 power lens, examine the casualty's eye from a distance of 50cm. The red reflex is a bright reflection from the casualty's retina, similar to the red eye on a photograph taken with a flash. Any reduction in intensity indicates something between the examiner and the casualty's retina.

Cornea. Examination 1724 The cornea should be transparent and smooth, giving an even and bright reflection of the illuminating light. Check for abrasions, lacerations and foreign bodies. Instill topical anaesthetic if there is lid spasm due to pain (Table 1702). Symptoms and signs include: • Foreign body sensation. • Pain. • Photophobia. • Redness (injection) or chemosis (swelling). • Decreased vision. 432 Chapter_17.qxd 28/09/2004 15:57 Page 433 17: Opthalmic injury

A white corneal infiltrate usually indicates a corneal abscess. The anterior chamber can fill with pus (hypopyon). Treatment is with systemic and topical antibiotics (Table 1702).

1725 Management of corneal or subtarsal foreign bodies • Removal of even superficial corneal foreign bodies is difficult without high, binocular magnification and good illumination. • Corneal foreign bodies can be buried in the corneal stroma or protrude into the anterior chamber. Deep corneal foreign bodies are often well tolerated and can be left; more severe damage and scarring may be caused by attempts to remove them. Further management is as for penetrating injury (1717). • Loose foreign bodies can be irrigated from the eye. If not, instil topical anaesthetic (Table 1702) and removed with a needle using a tangential approach whilst steadying the casualty's head. A cotton bud is useful to wipe away loose epithelium or superficial foreign bodies (Figure 1705). Further management is as for corneal abrasion (1726).

1726 Management of corneal abrasions

Abrasions are due to trauma; ulcers are caused by Beware of infective infection. conditions simulating corneal abrasion • Abrasions are best visualised after staining (e.g. herpetic or with fluorescein. bacterial ulcers). • If pain relief is required other than for examination, use oral analgesics. Topical Corneal abrasions anaesthetics slow epithelial healing. and foreign bodies are incapacitating • Instill medium-acting mydriatics to rest the eye but, with appropriate - use cyclopentolate or homatropine - and topical treatment, most heal within 24 hours. antibiotics (Table 1702). Apply a firm, double eye 433 Chapter_17.qxd 28/09/2004 15:57 Page 434 17: Opthalmic injury

pad ensuring that the upper lid is closed under the covering. • After 24 hrs, if an abrasion has healed, stop mydriatics and continue antibiotic drops for a further week. • Repeat above if not healed. • After 48 hrs, leave the eye open, even if it is unhealed and use copious ocular lubricants (Table 1702). Over-padding leads to corneal anoxia, oedema and reduced epithelial healing. • Consider referral to an ophthalmologist.

1727 Corneal infection (infectious keratitis). This requires immediate transfer to an ophthalmologist. If this is not feasible, start treatment with intensive, topical antibiotic drops for example, chloramphenicol every 30 minutes - (Table 1702) and transfer as soon as possible. Infectious keratitis may be associated with contact lens wear.

Conjunctiva 1728 Management of lacerations and foreign bodies: • Consider an underlying scleral laceration or intra-ocular foreign body. Evaluate for perforation (1716). • Irrigate with saline. • Pick out foreign bodies with forceps or wipe them away with cotton buds (Figure 1705). • Large lacerations require closure with 6/0 absorbable suture. • Use topical antibiotic drops (Table 1702). • Do not pad the eye(s).

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1729 Chemical injuries. In the field, acid burns are usually due to exploding vehicle batteries. Alkali burns are more serious than acid burns and are often due to caustic soda used in chemical latrines. Alkali can cross the cornea into an eye in 5 seconds, whereas acids coagulate tissue to form a barrier. The severity of the injury depends on the extent of: • Sloughing of corneal epithelium. • Corneal haze, obscuring iris details. • Corneal folds (corneal oedema due to loss of endothelial cells).

• Conjunctival and scleral ischaemia, seen as The Morgan blanched, avascular areas. Extensive limbal irrigating contact lens is useful ischaemia is a particularly poor prognostic sign: for dealing with it is seen as blanched, avascular areas at bilateral or multiple the limbus. chemical injuries. • Raised intra-ocular pressure. • Progressive opacification of the cornea. • Cataract formation

1730 A chemical injury to the eye is an emergency: • If it is suspected, irrigate the casualty's face and eyes with sterile eyewash or saline. Continue for 20 minutes. • Evert the eyelids (Figure 1705), remove any particles and direct irrigating fluid under them. • Consider chemical injury elsewhere, particularly to the airway. • Early and vigorous treatment with ascorbic and citric acid - topical Topveal four times daily - has greatly improved the outcome in alkali injuries. 435

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• All chemical burns should be urgently referred to an ophthalmologist.

Vitreous

Ultrasound can 1731 Opacification may cause loss of the red be used to examine reflex and obscure the fundus. Causes include: the retina and vitreous in the • Haemorrhage. presence of intraocular • Inflammatory or infective reactions, usually haemorrhage. due to a retained foreign body. Management is generally as for hyphaema (1720).

Fundus and retina. 1732 Examine both using direct ophthalmoscopy. Look for: • Retinal oedema and infarction (comotio), the retina appears white and cloudy, obscuring the choroidal pattern. • Haemorrhages look as if they have been "air-brushed" onto the retina. In more severe injury, haemorrhages are "blot-like" and the macula may show up as a "cherry red spot" against the infarcted retina. • There may be a darker mass of sub-retinal Always carefully or choroidal haemorrhage sometimes overlying record the position a crescentic, choroidal rupture concentric to of any intraocular foreign bodies. the disc. These may be • Retinal detachment looks like a waving net obscured later by further bleeding or curtain. Only 12% of traumatic detachments inflammation. occur immediately. Acuity may be normal if the macula is not involved and the media are clear. • Foreign body. Management is generally as for hyphaemia (1720).

436 Chapter_17.qxd 28/09/2004 15:57 Page 437 17: Opthalmic injury Laser injury 1733 Damage depends on the intensity of the burn. High energy injuries can cause corneal or lens opacity (cataract). Usually, the laser light will pass through the transparent media of the eye and cause a retinal burn. Effects can range from grey discolouration of the retina, a retinal hole, sub-retinal bleeding to an eye full of blood. In the field, manage as for hyphaema (1720). At Role 3 and 4, treatment options extend from conservative therapy through to surgical rotation of the retina.

Sympathetic Ophthalmia 1734 This occurs when one globe has been severely disrupted. It is rare if satisfactory, primary repair is carried out within 10 days of injury. Sight in the injured eye may ultimately be better than that in the sympathising eye. Removal of the globe may be indicated in the case of an infected or painful eye with no perception of light. This is not a field procedure. Evisceration (contents scooped out of sclera) is performed in preference to enucleation (whole eyeball removed).

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Maxillofacial Injuries

Introduction

1801 On the battlefield, 10-15% of casualties Definitive treatment who reach Role 1 have maxillofacial injuries. of maxillofacial Penetrating trauma, usually caused by fragment injuries is neither injury, is commoner than in civilian practice. rapid nor easy, and may involve The principles of initial management are: a multidisciplinary • Maintain the airway. Following maxillofacial approach. injuries the airway is at risk from the tongue falling back, fragments of bone or teeth, continued haemorrhage and soft tissue swelling. Clear and maintain the airway (0319). A definitive surgical airway may be necessary. • Diagnosis of associated head, ophthalmic or ENT trauma (15% have associated injuries). • Preparing the casualty for transfer to specialist care (1835). Provide simple splintage and analgesia (Figure 0701) for mandibular fractures. Do not let the • If transfer is delayed or the injuries unstable, casualty die for initiate treatment. Subtle injuries are unlikely want of an airway. Most casualties are to be life threatening. Most closed injuries may transferred in the be left without surgical intervention for up three-quarter prone to 10 days. Consider antibiotic prophylaxis position with (0816-0818). supervision..

Mechanism of Injury

1802 Penetrating trauma produces soft tissue Unless severe, injury and fractures at the site of impact. The bones maxillofacial injuries of the face and head are illustrated in Figure 1801. are rarely a cause of shock. Look for High velocity missiles that strike teeth or dense bone causes elsewhere. 439

ABC: Chapter 3

Body of mandible of Body Angle of mandible of Angle

Maxilla Mastoid process Mastoid

Zygoma

Zygomatic arch Zygomatic Temporal bone Temporal

Nasal bones Nasal Occipital bone Occipital

Supraorbital margin Supraorbital

Frontal bone Frontal Parietal bone Parietal Fig 1801 Bones of the face.

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cause high energy-transfer with comminution of bone, multiple fractures, tissue loss and contamination along the missile track. Low velocity missiles lead to local laceration and crushing.

1803 Blunt trauma results in predictable fracture patterns of the mid-face (Figure 1802) and at the condylar, angle and parasymphyseal regions of the mandible (Figure 1803). Approximately 50% of jaw injuries are blunt.

Management

General examination External 1804 Inspect all surfaces of the head, face and neck. Look for Remember that the unconscious • Asymmetry, depression or deformity of bony casualty may have landmarks and difference in eyeball level (1707). inhaled any missing teeth A chest X-ray Assessment is easiest immediately after injury. may be indicated to • Lacerations, bruising, haematomas or exclude this. tissue swelling. • Evidence of a basal skull fracture (1636). • Facial muscle weakness suggests damage to the facial nerve.

1805 Palpate all bony surfaces and margins, comparing both sides, to detect breaks in continuity of: Look for evidence of airway obstruction • Cranium. due to tissue oedema; it typically • Orbital rims. starts 60-90 minutes after injury. • Nose. • Zygomas and zygomatic arches. • Condyles.

441

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• Posterior border of the ramus and the lower border of the mandible. 1806 Examine for sensory loss, especially over the cheek and lower lip; tenderness and surgical emphysema. Pressing firmly inwards at both angles of the mandible simultaneously will flex the mandible and cause discomfort and movement at a fracture site if present. Pulling on the upper teeth with the head stabilised, will produce palpable movement intra-orally: • In the buccal sulcus in Le Fort 1 fractures.

• Externally at the infra-orbital margin in Le Fort 2 fractures. • At the zygomatico-frontal suture at the lateral orbital margin in Le Fort 3 fractures. A gloved finger gently passed into an open wound may reveal a fracture or foreign body.

Mouth 1807 Inspect for: Take care when inserting • Broken, missing or displaced teeth. a naso-pharangeal airway in the • Alteration in alignment of the teeth. presence of a suspected basal • Malocclusion - failure of the teeth skull fracture (0321). to meet correctly. There is a small risk of it ending up in • Limitation of mandibular movement the brain! and/or asymmetrical opening. • Bleeding, haematomas and tears of the mucous membranes of the cheeks, gums, floor of the mouth, hard palate and tongue. Palpate the teeth, dental arches, palate and maxilla to detect abnormal mobility. 442

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Eyes 1808 Examination points include: • Check pupillary size and response to light (1706). • Look for enophthalmus or proptosis (1707). • Check for subconjunctival haemorrhage (1636) or hyphaema (1719). • If conscious, check visual acuity (1705), eye movement and diplopia. • Pooling of tears and epiphora indicate lachrymal damage.

Ears 1809 Examine for: • Otorrhoea. • Ruptured eardrums. • Haemotympanum (1905). • Hearing deficit.

Pathophysiology and examination of facial fractures Upper third 1810 Fractures of the skull vault are suspected deep to penetrating wounds, under areas of depression or when bone edges are encountered by the examining finger.

Middle third

1811 Fractured zygoma Step deformity of the inferior orbital After nasal fracture (1913), this is the second most rim indicates a common bony, middle third facial injury. It usually fracture, of either follows blunt trauma and is suggested by one or the orbital rim itself, more of the following signs: zygoma, or middle third of the facial skeleton. 443

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Le Fort 1

Le Fort 2

Le Fort 3

Fig 1802. Classification of mid facial fractures according to Le Fort.

1. Step deformity of the inferior orbital rim (Figure 1703). 2. Diplopia. 3. Infraorbital paraesthesia or numbness indicating damage to the infraorbital nerve. 4. Subconjunctival haemorrhage. 5. Limited mouth opening (Figure 1703). 6. Flattening of the malar eminence. 444

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1812 Orbital blow out fractures. In addition to the first four of the features associated with a fractured zygoma, the casualty may also have: • Abnormal eye movements and displaced lateral canthus (Figure 1704). Typically, there is loss of upward and outward gaze due to inferior rectus muscle tethering (Figure 1703A). • Enopthalmos (1707). • The maxillary antrum will appear opaque on X-ray due to the presence of blood. It may also demonstrate the 'hanging drop' sign and disruption of the posterior wall of the antrum.

1813. Maxillary fractures Such fractures indicate the casualty has suffered significant violence. Classification is according to Le Fort (Figure 1802): • Le Fort 1: the palate and tooth-bearing parts of the maxilla are separated from the mid face. • Le Fort 2: the pyramidal fracture is at a higher level than Le Fort 1 and includes Any combination of the naso-ethmoidal complex but not the Le Fort 1,2 and 3 on zygomatic complexes. one side of the face may be combined • Le Fort 3: the whole of the facial skeleton with Le Fort 1,2 or 3 is separated from the base of the skull on the other. including the zygomatic complexes at the zygomatico-fontal suture and zygomatic arch. In addition to many of the features of a fractured zygoma and orbital blow out fracture, there may also be: • Lengthening of the face and dished-in deformity. • Disruption of dental occlusion. • CSF rhinorrhoea.

• 'Cracked cup' note on percussion of the 445 upper teeth.

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• Bleeding, especially from the nose, may be profuse. Haematomas may result in severe soft tissue swelling. Fractures may be visible on radiographs along the lateral wall of the maxillary sinuses and the inferior margin of the bony orbit.

The lower third. 1814 A blow to the chin may cause uni- or bilateral fractures of the condyles, or fracture Always suspect the centre of the body of the mandible near the multiple fractures in symphysis menti ('guardsman's fracture'). A blow to the mandible. the side of the jaw will fracture it at the site of impact. There may be associated fractures of the mandible near the canine tooth or contralateral condylar neck. Common mandibular fractures are illustrated in Figure 1803. Displacement depends on the pull of the muscles attached to the fragments. Unstable, anterior mandibular fractures, may prejudice the airway by allowing the tongue to fall backwards. Respiratory embarrassment can be caused by gross swelling of tissues around the upper airway. Diagnosis of mandibular fractures is straightforward if the casualty is conscious and the fracture displaced. Look for: • Irregularity of the teeth, abnormal dental occlusion or deviation of the jaw to one side. • Pain and mobility about the fracture site. • Paraesthesia over the lower lip signifying damage to the inferior dental nerve. • Swelling and tears of the mucous membranes of the cheeks, gum and floor of the mouth. • Fractures of the mandibular condyle are characterised by disordered occlusion without nerve signs. They are accompanied by pronounced stiffness on mouth opening and 446

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Neck of condyle Angle of the mandible Anterior fracture

Fig 1803 Common mandibular fractures.

tenderness over the condyle when compression is applied to the chin. A 'gagging' or open bite is usually due to a fracture of the ramus or fracture-dislocation of the condyle, but may also be associated with posterior displacement of mid-facial fractures.

Management of facial fractures Radiological investigation 1815 Views are taken at right angles to Experience has minimise superimposition of the facial structures shown that it is preferable for the on the skull base. casualty to arrive at a special unit • Suspected vault fractures are diagnosed 48 hours after by AP and lateral radiographs. wounding, rather than be operated • Fractures of the zygoma, orbit and middle third on earlier by a are usually investigated by 10 and 30-degree non-specialist occipito-mental radiographs, lateral facial and and possibly be submento-vertical views. mismanaged. • Fractures of the body of the mandible are best seen on panoral tomography (OPG/OPT), lateral oblique, PA or PA oblique views. The PA oblique, or rotated PA is useful for throwing the mandibular symphysis clear of superimposition of the cervical spine. If not otherwise imaged, a reverse Towne's view provides reliable detail of the mandibular condyles. 447 Chapter_18.qxd 28/09/2004 15:57 Page 448 18: Maxillofacial Injuries

• Complex injuries of the face are confirmed by CT scan, ideally with 3-D reconstruction.

General management 1816 Control of bleeding

Ligation of the External bleeding from the head and neck can external carotid is usually be controlled by applying a pressure dressing rarely needed to and sitting the casualty upright. NB: taking care that control facial bleeding. this does not interfere with the airway or put pressure on the globe. A useful technique in the neck is to use a fluid bag (0330). Alternatively, ligate the bleeding vessel with the aid of a good light, retraction and suction. Bleeding from the mid-face may require packing, e.g., a penetrating wound of the maxillary antrum. In the case of severe bleeding from the nose, insert an anterior nasal pack (1916). An alternative emergency measure is to introduce two balloon catheters (1917). If the palate has a midline split, the maxilla will be unstable and nasal packing will not tamponade bleeding. If expertise and equipment are available, fix a miniplate over the midline of the palate, drilling through the mucosa, to stabilise the maxilla before packing the nose.

1817 Pain relief Severe pain is not usually a feature of maxillofacial injuries. Swallowing and talking can be uncomfortable. Give analgesia (Figure 0701), but take care to avoid respiratory depression.

1818 Fracture treatment Nasal packing is For most facial injuries, no immediate splinting is contra-indicated in the presence of CSF required. Mobile, painful fractures can be supported rhinorrhoea. with a bandage (Figure 1804). Treatment of facial fractures should be carried out as soon as practicable. Most can be left untreated for up 448 to ten days without adversely affecting the outcome.

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Fig 1804 Support of the injured jaw.

Because of the regional blood supply, healing is often uncomplicated and rapid. Fracture union usually occurs in 3-4 weeks in the maxilla and 6-8 weeks in the mandible. Open reduction and internal fixation using titanium plates, is favoured by many civilian surgeons in preference to external fixation, even when treating comminuted fractures. This allows accurate alignment, does not interfere with the airway and the casualty can soon eat a semi-solid diet. Existing lacerations may be used for direct access to fractures. Where such equipment or expertise is unavailable, treatment should be aimed at preserving as much viable bone and soft tissue as possible and preventing infection.

1819 Antibiotics Fractures involving the teeth and/or sinuses are regarded as compound and the casualty treated with peroperative antibiotics (0817, 0818). Longer courses should be given if wounds are contaminated or treatment is delayed. Give tetanus toxoid where necessary (0828).

1820 Further management With significant tissue loss, long term problems often occur due to scarring and wound contracture. Tissues 449

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should be maintained in their anatomical positions and defects packed or dressed. Definitive reconstruction is best carried out early by multidisciplinary teams once local infection is cleared and the casualty's general condition permits.

Fractures of the upper third

Definitive sinus 1821 Depressed or comminuted fractures of the surgery should only skull vault often require treatment in conjunction with be undertaken by an a neurosurgeon (1635). Isolated fractures of the experienced supra-orbital rim or frontal bone without a dural surgeon. There is a risk of stenosis of tear, may require reduction and fixation because the frontal sinus. of pressure on the orbital contents. These can be readily treated under general anaesthesia via a bicoronal flap. In the field, the wound should be excised and dressed. Give antibiotics (0817, 0818) and refer for urgent repair.

Fractures of the middle third 1822 Zygoma Displaced fractures are reduced via a temporal (in the hairline), or oral incision, using an elevator to reposition the zygoma. Unless eye signs or limited mouth opening are present, failure to reposition the fracture results in no more than a cosmetic defect. Reduced fractures are generally stable and do not require miniplate fixation. The risk of retrobulbar haemorrhage is small, but is increased in fractures treated late. After surgery, visual acuity should be regularly assessed. Orbital decompression is indicated if the casualty develops: • Proptosis. • Increasing pain. • Diminished visual acuity. In an austere environment, medical treatment with Acetozolamide 500mg i.v. (or 200ml of 20% 450 mannitol plus 8mg Dexamethasone), may reduce

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globe pressure and delay ischaemic changes in the optic nerve.

1823 Orbital blow out fractures Treatment involves replacing orbital structures which have herniated into the maxillary antrum and releasing muscles trapped in the fracture line (Figure 1703). This commonly requires insertion of a silastic or titanium mesh via a subciliary incision. Alternative graft materials include: cartilage, bone and lyophilised pig dermis. Casualties should not blow their nose for 3 weeks; this may force antral contents into the orbit, causing surgical emphysema and infection.

1824 Maxillary fractures The fracture is reduced so as to obtain a normal dental occlusion. If there are no associated penetrating injuries, this may be achieved by closed manipulation. Open reduction allows precise fixation of fractures in their correct anatomical position. Methods of fixation include: internal wiring or suspension wiring and intermaxillary fixation, internal miniplate fixation and external fixation. Mid face injuries may bleed heavily. Occasionally, a displaced mid face fracture may occlude the upper airway. This can be reduced bimanually and held in place by pulling on the nose (Figure 1805). Alternatively, insert Foley catheters into each posterior nasal space, inflate the balloons and apply forward traction (Figure 1905).

Mandibular fractures 1825 These are managed by open reduction and fixation using miniplates, or by eyelet wiring. Dental occlusion should be the guide to the correct repositioning of the fragments, rather than the radiographic appearance of the bone ends. 451

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Fig 1805 Bimanual reduction of a Le Fort 3 fracture which is obstructing the airway.

1826 Fractures of the mandibular condyles, Almost any soft wire can be used even if displaced, are commonly not subjected to for intermaxillary the difficult procedure of open reduction and fixation. fixation, even fuse Instead, a soft diet is prescribed. If the casualty can wire. Failing this, achieve their normal dental occlusion, surgery is not elastic bands wrapped around required (NB: eating will be painful in the first few the cleats of arch days after injury). If the occlusion is still deranged bars will produce after one week, the fracture is treated by fixing stable fixation. eyelet wires or arch bars on the teeth and placing intermaxillary elastics to restore the correct occlusion.

1827 Only teeth which are loose should be removed. Firmly embedded teeth near fracture lines are best left alone. Even damaged teeth can be used for fracture immobilisation. If the casualty wears a denture, this may be used for fracture stabilisation by inter-denture wiring or fixing it across the fracture site.

1828 Fixation techniques • The simplest form of intermaxillary fixation is by interdental eyelet wiring. In conjunction with circum-zygomatic wires, it can provide a degree of craniomaxillary fixation. Eyelet wires are most commonly made from soft, stainless steel wire of 452 Chapter_18.qxd 28/09/2004 15:57 Page 453 18: Maxillofacial Injuries

a)

b)

Fig 1806 Techniques of interdental wiring.

0.5, 0.4 or 0.35 mm diameter, pre-stretched by 10% (Figure 1806). • An arch bar is used where multiple teeth are missing. This is fixed to the existing teeth using wire (Figure 1807). Once in place, the cleats on the bar can be used to stabilise and hold the fragments and to apply intermaxillary fixation. • An alternative to miniplate fixation for an unstable mandibular angle fracture, is to drill two holes, either via the intra-oral route or a submandibular incision and fix the fragments 453 Chapter_18.qxd 28/09/2004 15:57 Page 454 18: Maxillofacial Injuries

Fig 1807 Using an arch bar: several methods of fixation illustrated.

together using stainless steel wire (Figure 1808). This is followed by intermaxillary fixation. • For avulsion injuries causing continuity defects of the mandible, the remaining teeth are placed in intermaxillary fixation and external pin fixation is applied to stabilise the bone fragments. (Figure 1809). The intermaxillary fixation is best left on but can be released for casualty transfer. Distraction osteogenesis may be a useful adjunct for the reconstruction of larger bony defects.

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Fig 1808 Fixing a mandibular fracture using wire (usually combined with intermaxillary fixation).

Soft tissue injuries Excision and closure

1829 Wound excision and closure are described Always cover in 0504. Additional points include: exposed bone with soft tissues. Ideally, dental or fracture fixation is carried out first. If there is delay, lacerations overlying a bony injury are closed. Contaminated wounds should be excised (LA or GA) to avoid infection and skin tattooing (0503, 0504). Particles can be removed with forceps, a blade or a sterile scrubbing brush using hydrogen peroxide. Such wounds need antibiotic treatment (0816, 0817). Preserve as much viable soft tissue and bone as possible. If contused or ragged, trim 1-2mm off the skin edge using ophthalmic scissors and a No 15 blade so as to achieve non-contaminated, non-bevelled edges. If bone fragments are attached 455

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Fig 1809 External fixation of a mandibular fracture where there is bone loss. to periosteum or soft tissues, leave the bone in situ. Small areas of borderline viability often survive. Use absorbable sutures within the oral cavity such as 3/0, undyed polyglactin (Vicryl rapide™). Close deep facial wounds in layers. A watertight closure over a fracture is desirable. Avoid dead space. Undermining of the edges may be required to reduce tension (Figure 0504). Drains are rarely necessary. Remove skin sutures after 4-5 days. Steristrips can be used for superficial wounds, or to support wounds after suture removal.

1830 Facial nerve If severed branches are encountered they should be tagged with a non-resorbable suture for later anastomosis and the wound closed (1910).

1831 Soft tissue loss If there has been extensive soft tissue loss so that closure without tension is impossible, the underlying bone can be covered by suturing skin to mucosa (Figure 0503). This can be revised later. Large areas of tissue loss can be reconstructed using local or distant flaps. Such areas may be covered in Betadine soaked swabs until the casualty is 456 transferred for definitive treatment.

Wound Management: see Chapter 5 Chapter_18.qxd 28/09/2004 15:57 Page 457 18: Maxillofacial Injuries Indications for a surgical airway in maxillofacial casualties 1832 These include: • Where there is doubt about the continued patency of the airway without supervision, especially during transfer. • Wounds of the jaw associated with laryngeal and some pharyngeal injuries. • Intermaxillary fixation with any degree of respiratory obstruction. • Gross tissue loss which is associated with severe swelling.

Nursing of maxillofacial casualties 1833 Essentials are: • Pain control. • Oral hygiene. Brush teeth daily and regularly irrigate the mouth with 0.9% saline or a weak chlorhexidine mouthwash. Intermaxillary fixation may dry and traumatise the lips. Apply petroleum jelly frequently. • An appropriate soft diet for the period of fixation. In the case of intermaxillary fixation, the casualty requires a per oral, liquid diet. Alternative approaches are via a fine bore nasogastric tube or percutaneous gastrostomy.

Wisdom Teeth 1834 In recent conflicts, a significant cause of sickness amongst UK troops has been impacted wisdom teeth. The affected tooth (usually the lower) is partly erupted, allowing food and debris to become trapped around and beneath the gum. If the soldier is unable to clean the area, it becomes inflamed, infected and painful. 457

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• Cure is by removing the tooth. Alternatively, it is often helpful to extract the opposing tooth from the upper jaw. • Until dental treatment is available, prescribe warm saline mouth baths and antibiotics e.g., penicillin V, 500 mg four times daily, or metronidazole, 400 mg three times daily (0816, 0817).

Transfer 1835. Considerations are: • Casualties without a definitive airway should be transferred in the three-quarter prone position (Figure 0308). They must be carefully supervised. • A suture through the tongue does not produce adequate control of the airway. If in doubt, perform a surgical airway (1832). • Attendants must be instructed in the dangers and management of respiratory obstruction. • For casualties transferred in intermaxillary fixation, especially by air or sea, it is mandatory that wire cutters are available. If the casualty develops respiratory obstruction any intermaxillary fixation must be released immediately. Anti-emetics may be prescribed before transfer but, are not a substitute for careful supervision. • The priorities for transfer of maxillofacial casualties are: • T1 Airway problems. • T2 Multiple facial injuries without airway compromise. • T3 Uncomplicated maxillofacial injuries.

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Injuries of the Ear, Nose and Throat (ENT)

Introduction

1901 Missile and blast weapons affecting the head and neck can cause injury in areas served by Following blast injury deafness one or more of the following specialities: neurosurgery may impair (Chapter 16), ophthalmology (Chapter 17), communication maxillofacial surgery (Chapter 18), and ENT. with the casualty. Early management of ENT injuries is generally straightforward. The immediate risk is airway obstruction due to disruption of the pharynx and larynx, a facial fracture or bleeding and swelling around the upper airway. Because endotracheal intubation is likely to be difficult and require anaesthetic expertise, securing the airway may need a cricothyroidotomy or tracheostomy (0322).

1. Ear

1902 Rupture of the tympanic membrane, disruption of the ossicles and damage to the inner ear, can all affect hearing. Balance may be disturbed by injury to the vestibular apparatus. The gross anatomy of the ear is illustrated in Figure 1901.

External ear Injuries to the pinna Incorrect treatment of injuries to the 1903 These include haematoma, simple external ear can laceration and partial or complete avulsion: result in cosmetic deformity. • A haematoma requires prompt treatment to avoid cartilaginous necrosis and development of a "cauliflower ear". If liquefied, aspirate using 459

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Auricle Temporal Malleus Incus Semicircular bone canal Helix Auditory nerve

Stapes

Cochlea

Pharyngotympanic (Eustachian) tube Tympanic membrane A External Lobule accoustic meatus

Long process of incus

Posterior Anterior

Handle of Tympanic malleus membrane B

Fig 1901 A) Structures of the ear B) Normal appearance of the tympanic membrane.

a syringe and large bore needle. If a solid or organised clot is present, incise and evacuate this under aseptic conditions. Afterwards, apply a pressure dressing. • For a simple laceration, excise damaged auricular skin and close with interrupted, non-absorbable sutures (e.g., 4/0 Prolene). • Following partial avulsion of the auricle, excise nonviable tissue and re-approximate as illustrated in Figure 1902A. Do not suture cartilage; this may cause infection (perichondritis) leading to necrosis. • If a portion of the auricle is lost, suture the remaining anterior and posterior skin layers over the exposed cartilaginous edge (Figure 1902B). A plastic surgical repair can be undertaken later. 460

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A

B

Fig 1902 A) Suturing a simple laceration of the external ear. B) Repair after tissue loss.

Injuries to the ear canal 1904 Treatment is generally to suture and pack: • Repair lacerations of the external auditory meatus using absorbable sutures (e.g., 4/0 Vicryl). If this is difficult, approximate the edges as best you can. 461 Chapter_19.qxd 28/09/2004 15:57 Page 462 19: Injuries of the Ear, Nose and Throat (ENT)

• Pack the lumen with bismuth iodoform paraffin paste (BIPP) ribbon gauze to keep the meatus patent and prevent stenosis. The pack should be left in until formal assessment by an ENT surgeon. • If there is otorrhoea, place a cotton wool dressing in the entrance of the ear canal.

Middle ear

The most important 1905 Damage to the tympanic membrane (TM) delayed complication is common and often associated with more serious of middle ear injury injuries elsewhere. Causes include direct penetration, is infection. base of skull fracture involving the tympanic ring and blast injury. Haemorrhage into the TM may also occur without rupture (haemotympanum), causing immediate deafness. When damage is suspected, examine the ear carefully using an otoscope with a sterile tip. Do not syringe. • If the tympanic membrane is ruptured, avoid interference. • Protect from further injury: • Ideally, the casualty should wear ear defenders - there may be tactical constraints! • Keep it dry - place cotton wool in the entrance of the ear canal. • Nose blowing is contraindicated until the rupture has healed, (approximately 6 weeks). • Seek an early review by an ENT Surgeon. The tympanic membrane usually heals spontaneously. If not, it can be repaired later. • Antibiotics are not routinely required. If suppuration develops, treat with topical and systemic antibiotics: • Sofradex™ or Gentisone HC™ 2 drops 462 Chapter_19.qxd 28/09/2004 15:57 Page 463 19: Injuries of the Ear, Nose and Throat (ENT)

three times daily for at least 5 days or until otorrhoea has stopped. • Amoxicillin (500mg) or co-amoxiclav (375 to 625mg) three times daily for 7 days. • Because of the risk of meningitis, administer antibiotics in the presence of CSF otorrhoea in a battlefield situation (0818). Leakage usually ceases spontaneously (1637).

Inner ear 1906 Causes of inner ear damage include: • Continuous loud noise. • Blast injury. • Otitic barotrauma. • Head injury.

Blast injury 1907 The tympanic membrane (TM) is particularly susceptible to overpressure (0219) and ruptures at about 35kPa. The shock wave and high intensity noise, may cause sensorineural hearing loss (damage to the function of the cochlear nerve). Hearing usually improves rapidly, but high frequency losses can persist. When possible, the casualty should avoid exposure to further acoustic trauma by wearing ear defenders. Small overpressures in a confined space can cause dislocation of the ossicles by direct displacement or, distortion of the TM at the attachment of the malleus. Deafness may result.

Otitic barotrauma 1908 Damage may occur due to changes in external pressure e.g., during flying and diving, and where the Eustachian tube fails to adequately 463

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equalise pressure in the middle ear. Negative pressure causes medial displacement of the tympanic membrane resulting in hyperaemia, oedema and ecchymosis of the middle ear mucosa. The tympanic membrane may rupture. In extreme cases, a perilymph fistula develops secondary to rupture of the membrane of the round window. The casualty presents with profound vertiginous symptoms, nystagmus and sudden sensorineural hearing loss: • Keep the ear dry. • Otalgia and aural fullness are reduced by decongestant nasal drops e.g., xylometazoline hydrochloride 2 drops three time daily for 7 days for a maximum of 2 weeks. • Dizziness usually slowly improves. Treat vertigo with prochlorperazine, 5mg three time daily (maximum 2 weeks). • Seek urgent ENT advice.

Head injury

Symptoms of 1909 Labyrinthine concussion - mild unsteadiness inner ear damage with change of head position - generally only occurs include deafness, after major head injury. The casualty may also have high-pitched tinnitus nystagmus and a mild, high frequency sensorineural and, in severe cases, vertigo. deafness. As the effects of the concussion resolve, so do the signs and symptoms. A blow sufficient to cause a transverse fracture of the temporal bone may produce a high frequency sensorineural deafness. • Treat vertigo with prochlorperazine, 5mg three time daily (maximum two weeks).

Facial nerve 1910 Facial nerve paralysis - partial or complete - can occur following fracture of the skull base. 464 Chapter_19.qxd 28/09/2004 15:57 Page 465 19: Injuries of the Ear, Nose and Throat (ENT)

Approximately 80% of temporal bone fractures are longitudinal; the inner ear is generally not involved and facial nerve damage is unusual. If there is paralysis, it tends to be late and occur as a result of swelling. Prognosis is generally good. The inner ear is often in the line of a transverse fracture, resulting in total sensorineural hearing loss, horizontal nystagmus and giddiness due to destruction of the vestibular labyrinth. Approximately 50% of these casualties will suffer a facial paralysis. • In general, early facial nerve palsies require urgent repair by an experienced ENT surgeon via a middle ear and mastoid exploration.

2. Nose

1911 Injuries of the upper third of the face tend to involve the frontal sinuses and can be associated with dural tears and CSF leakage. Fractures of the middle third of the face may be confined to the nose or involve the maxilla and the zygomatic arch (Figure 1802).

Septal haematoma 1912 This follows a direct blow to the nose. A septal haematoma may occur in combination with fracture of the nasal bones. The casualty complains of nasal obstruction. On examination, the septum bulges and resembles a cherry tomato. Treatment is prompt incision and drainage. • Under aseptic conditions, incise the anterior and dependent portion of the haematoma and evacuate the contents. • Insert bilateral intranasal packs; leave them in-situ overnight to prevent re-accumulation of the haematoma.

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Fig 1903 Insertion of a nasal tampon.

• Give co-amoxiclav (625mg three times daily) for 7 days. • Neglecting a septal haematoma leads to infection, abscess formation, cartilaginous necrosis and nasal deformity.

Nasal fractures Simple fractures 1913 Management of an obviously displaced fracture: • If seen immediately after injury, attempt reduction (without anaesthetic). • If presentation is delayed, reduce the fracture between 7 and 14 days post-injury. This can be done under local or general anaesthesia. To obtain local anaesthesia, spray inside the nose with lignocaine or cophenylcaine and inject approximately 2ml of 2% lignocaine with 1:80,000 adrenaline, at various points around the bony nasal skeleton using a dental needle. 466 Chapter_19.qxd 28/09/2004 15:57 Page 467 19: Injuries of the Ear, Nose and Throat (ENT)

Fig 1904 Insertion of a BIPP ribbon gauze pack.

Open fractures 1914 Treatment is wound excision and early reduction under GA. • If the wound is clean, close the defect immediately using fine, non-absorbable sutures. • If the wound is contaminated, excise and perform delayed primary closure (0503). · Give co-amoxiclav (625mg three times daily) for 7 days.

Epistaxis

1915 Bony injury to the nose, maxillary antrum or Haemorrhage ethmoid cavities, can cause significant haemorrhage from one side (1816). This is controlled by packing. can manifest itself equally from both nostrils. 1916 Anterior nasal packing • The easiest method is to insert a nasal tampon - application is aided by applying aqueous lubricating jelly to the tampon (Figure 1903). • For more specific control, a BIPP ribbon gauze pack is inserted in layers (Figure 1904). 467

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Fig 1905 Insertion of balloon catheter to control epistaxis

• Management of epistaxis in the presence of a midline split in the palate - see 1816.

1917 Posterior nasal packing This may be required if anterior packing fails to control the epistaxis.

When inserting • Insert a 12 or 14G Foley catheter with a 20ml balloon catheters to balloon into the nose until the tip of the catheter control epistaxis, is just visible behind the soft palate. ensure that the nasal rim is protected with • Inflate the balloon with air or water to gauze to prevent three-quarters capacity and pull the catheter pressure necrosis. back until the balloon occludes against the choana at the back of the nose (Figure 1905). • Tape the catheter to the side of the face.

3. Injury to the Face and Para-Nasal Air Sinuses

1918 Management of fractures are discussed in paragraph 1818. Skin wounds can usually be closed primarily after minimum excision (0504).

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Cervical spine 1919 Blunt trauma is discussed in paragraph 0307 and penetrating injury in 0308. Ensure that neck radiographs include the most commonly injured vertebrae - C6 and C7. Where a fracture or dislocation is suspected, perform odontoid peg and AP views in addition to a lateral radiograph. CT scanning may allow a more confident diagnosis.

Blunt trauma to the anterior neck

1920 The classic cause is impact with the Any history of blunt steering wheel or motorcycle handlebars in a road trauma to the neck traffic accident. The mechanism of injury is any direct should always raise blow from whatever cause. The aide memoire the question of laryngeal injury. 'TWELVE' is useful during the primary survey (0309). Signs and symptoms of anterior neck trauma are sometimes subtle. During the secondary survey look for: • Hoarseness or change in voice quality. • Dysphagia. • Odynophagia. • Pain and tenderness on palpation. • Surgical emphysema. • Ecchymosis.

Management

1921 When available, perform laryngoscopy to Failed attempts to evaluate the mobility of the vocal cords and patency intubate a casualty of the airway. with a significant neck injury, may risk completely losing an 1922 Minor neck injury already marginal airway. This is a task • In the absence of hoarseness or change in voice for an experienced quality, dysphagia, surgical emphysema and anaesthetist. 469 Chapter_19.qxd 28/09/2004 15:57 Page 470 19: Injuries of the Ear, Nose and Throat (ENT)

abnormal laryngoscopy findings, the injury can be managed conservatively. Observe the casualty for a minimum of 24 hours to exclude delayed airway compromise. Give 3 doses of 4 - 8mg dexamethasone i.v.

1923 Major neck injury • All casualties who have suffered significant blunt trauma to the neck require a secure airway. In an emergency, perform a cricothyroidotomy under LA (3005). Where time, experience and circumstances allow, undertake a tracheostomy (3007). • Adjunctive medical treatment includes: • 4-8mg of dexamethasone i.v. three times daily for 1-3 days. • Humidified oxygen. • Gastric acid inhibition - ranitidine 50mg twice daily i.v. • If the mucosa has been disrupted, give antibiotics (0817). • Oral feeding due to pain and swelling will initially be difficult. Nasogastric feeding should be started as soon as possible. • Transfer the casualty to a specialist unit for CT imaging and formal direct larygopharyngoscopy, oesophagoscopy and bronchoscopy. This will allow the extent of the injury to be ascertained and formal repair planned and executed.

Penetrating neck injury 1924 The neck is divided into 3 zones (Figure 1906) based on patterns of vascular injury: • Zone 1: contains the vessels at the root of the neck: the brachiocephalic trunk, subclavian and 470

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III

II

I

III

II

Cricoid cartilage

I

Fig 1906 Penetrating neck injury - classification according to zones.

common carotid arteries and their corresponding veins. The other main structures are the thoracic duct, thyroid gland, trachea, oesophagus and spinal cord. • Zone 2: contains the internal and external carotid arteries, internal jugular veins, vertebral arteries, larynx and hypophayrnx, spinal cord and cranial nerves X, XI and XII (Figure 1015). • Zone 3: contains internal and external carotid 471 Chapter_19.qxd 28/09/2004 15:57 Page 472 19: Injuries of the Ear, Nose and Throat (ENT)

arteries, vertebral arteries, internal jugular veins, cranial nerves V and VII to XII and the spinal cord. The most common site of injury is Zone 2 followed by Zones 1 and 3. Identifying the zone of injury has implications for the surgical approach (1036-1039).

1925 Penetrating injuries are life threatening due to • Disruption of the trachea. • Bleeding - exsanguination is the commonest cause of death following neck injury. Haematoma may also cause tracheal compression. • Surgical emphysema and subsequent infection within the tissue planes.

Signs and symptoms of penetrating neck injury

Perform a surgical 1926 These include: airway whenever there is doubt about • Vascular injury: shock, profuse bleeding, the continuing evolving stroke, expanding haematoma, adequacy of the haemoptysis, haematemesis and the presence airway, especially of a bruit or thrill over the wound. when supervision is likely to be poor • Laryngotracheal injury: subcutaneous during transfer. emphysema, hoarseness, respiratory distress "The time to do a tracheostomy is and stridor. when you first think about it" - Mosler • Oesophageal injury: limited signs and symptoms may make early diagnosis difficult. Clinical features can include: neck pain, blood in saliva or nasogastric aspirate and the presence of surgical emphysema in the neck. · Spinal cord injury: there may be a mixture of neurological signs including hemi or quadriparesis, with or without spinal shock syndrome - hypotension without a tachycardia.

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Treatment 1927 Measures include: Neck exploration must be undertaken • Where the airway is at risk, perform a by an experienced cricothyroidotomy (3005) or tracheostomy (3007). surgeon. • Control haemorrhage (0330) and resuscitate (0331). • In the field, the absence of angiography and interventional radiology mean that all injuries where the platysma has been penetrated, must be explored, even in asymptomatic casualties. Exposure and treatment are discussed in 1037-1039.

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Spinal Injuries

Introduction

2001 The spine is a bony, articulated structure When a fracture that extends from the base of skull to the pelvis; is seen in one part it protects the spinal cord and supports the frame. of the spine, The centrally located cord divides at L1 into the a second, non-contiguous cauda equina comprising multiple nerve roots. fracture is present in Spinal trauma is uncommon during military ~10% of casualties operations and usually occurs in combination with - this must be other injuries. Damage to the bones can cause looked for. instability, whilst injury to the spinal cord may result in neurological deficit. Outcome following cord injury is dependent upon: • Level of injury. • Early recognition. • Prevention of secondary insult, both mechanical and physiological. • Prevention of complications: respiratory, gastrointestinal, urological and pressure sores. Spinal casualties require specialist care at Role 4 to optimise recovery.

Aetiology

2002 Spinal damage can be caused by blunt injury, including blast, penetrating injury or combinations of both. Penetrating neck wounds involving the bony cervical spine and spinal cord, carry a 95% mortality (0308). The military surgeon is far more likely to be called upon to deal with blunt rather than penetrating trauma. 475

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Blunt The frequency 2003 Fractures and dislocations of the spine of gunshot wounds in military personnel are typically seen after RTAs, in civilian practice affecting the spinal tactical parachute drops, falls, sports injury and cord varies between bodily displacement secondary to blast. The cervical <1% in Croatia to up spine and thoraco-lumbar junction are particularly to 25% in the USA. at risk. There may be disruption to the bone or soft tissues, resulting in an unstable injury. At this stage, the casualty may or may not have spinal cord injury producing neurological deficit.

Penetrating 2004 High energy-transfer wounds are often fatal due to associated injuries. Fragments or bullets can damage the spinal cord directly and affect a variable number of adjacent levels. Alternatively, the shock wave of the missile passing close to or striking the vertebrae, can produce indirect injury (0206).

Management

History 2005 Features suspicious of spinal trauma are described in 0307 and 0308. Neurological deficit may be readily apparent in a co-operative casualty. It is frequently missed in the unconscious or those with multiple injuries. Symptoms may include localised spinal pain or regional discomfort.

Examination During primary and secondary 2006 A neurological examination is undertaken surveys, spinal cord during the secondary survey. injury can mask coexisting intra- • Inspection of the back requires a four man thoracic or log roll (Figure 0323). abdominal injuries e.g., guarding and • Look for wounds, swelling or palpable deformity. tenderness may be absent. • Examine for associated injuries, including 476

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calcaneal fractures, lumbar burst fractures Casualties with spinal injury should and multi-level spinal cord damage. also be considered • The level of cord damage can be estimated from to have head injuries until proven assessing sensory disturbance (Figure 2001). otherwise and vice and motor weakness (Table 2001). Look for versa, in particular, sacral sparing i.e., the presence of peri-anal those who are sensation and anal muscle tone and contraction, unconscious. this indicates incomplete spinal cord damage. • Respiratory difficulties are a sign of cervical trauma (Figure 2001). Diaphragmatic breathing and paradoxical chest wall movement are features of lower cervical injury. In high cervical injuries, there is loss of diaphragmatic innervation (C3,4 and 5). • Loss of sympathetic tone results in bradycardia and hypotension. The male casualty may have an erection. Findings should be carefully documented. Attention to detail is vital; the initial neurological examination is often the most important and is a guide to the ultimate prognosis.

Investigation 2007 As long as the casualty is appropriately immobilised, plain radiographs can wait until Role 3. CT scanning is undertaken at Role 3 or 4 to clarify vertebral and cord damage.

Treatment at Role 1 and 2 2008 If there is any doubt regarding the presence of a neurological deficit or stability of the spine, then the casualty should be assumed to have an unstable spine, until proven otherwise at Role 3. If this is done, radiographic clearance of the spine can be safely deferred. • Management of ABC. This will minimise secondary physiological insult to the traumatised 477

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1st Cervical DEATH Paralysis 7th Cervical upper and lower limb

Paralysis lower limbs

12th Thoracal

5th Lumbar Nerves for bladder and anus

A

C4 C4 C5 T4 T6 T1 T10 C6 S4 L1 C7 S5 S3 C8 S3 C8

L2

L3

L4

S1 S1 B L5

Fig 2001 A) Effects of spinal cord damage on respiration and motor function. B) Sensory dermatomes

spinal cord. Give i.v. fluids to counteract the loss of vaso-motor tone but, avoid over transfusion. Atropine and vasopressors can be of benefit in neurogenic shock. • Apply three point, cervical spine immobilisation 478 Chapter_20.qxd 28/09/2004 15:57 Page 479 20: Spinal Injuries

C-5 Deltoid (biceps jerk C5, 6) C-6 Wrist extensors (extensor carpi radialis longus/brevis) C-7 Elbow/extensors/triceps jerk (triceps) C-8 Finger flexors to middle finger (flexor digitorum profundus) T-1 Little finger abductors (abductor digiti minimi) L-2 Hip flexors (iliopsoas) L-4 Knee extensors (quadriceps; knee jerk L3,4) L-5 Ankle dorsi flectors (tibialis anterior) S-1 Ankle planter flexors (gastrocnemius, soleus; ankle jerk S1,2)

S-5 Anal reflex

Table 2001 Key muscle(s) and their spinal nerve segment.

(0318) and fix the casualty to a spinal board (Figure 0324). NB: pressure sores start to develop after 30 minutes. Pad well, remove the contents of back pockets and move the casualty off the board as soon as possible.

• Ventilatory support, if appropriate may be Do not dismiss required in those with high cervical cord injuries. hypotension as being secondary • Because of the risk of aspiration, pass a to the spinal cord nasogastric tube; leave it on free drainage injury until all potential sources and aspirate the tube regularly. of bleeding have been excluded. • Catheterise the bladder and monitor fluid balance. • Consider prophylactic antibiotics (open injuries - 0818; associated penetrating abdominal injury - 0817), antacid treatment (e.g., ranitidine) to prevent stress ulcers and Steroids are not DVT prophylaxis (0980). considered of value in acute spinal • Analgesia (Figure 0701). management. • Sedation for agitation, but, first exclude a medical cause .

Transfer 2009 Move fixed to a spinal board or using a full size vacuum mattress. Casualties should be 479

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appropriately marked e.g.; "Unable to move please alter position 2 hourly" Where resources and experience are available, immobilise the cervical spine using skull traction for example, Gardner-Wells' callipers and transport the casualty on a turning frame - Stryker or Povey frame. Facilities and medical experience must be available to deal with potential complications en-route. Comprehensive documentation must accompany the casualty.

Treatment at Role 3 and 4 Nursing 2010 Appropriate care by a multi-disciplinary team will prevent complications and optimise outcome after cord damage. Considerations include: • Respiratory Regular chest physiotherapy and, when indicated, ventilatory support. • Gastrointestinal Nasogastric intubation to combat ileus. Maintenance of nutrition (high protein diet). Prevention of faecal impaction i.e., suppositories, enemas, manual evacuation. • Genitourinary Catheter care. Consider a supra-pubic catheter. • Locomotor Early mobilisation of paralysed joints to prevent contracture. • Skin Avoid soiling with faeces or urine. Two hourly turning. Assessment for pressure sores. 480 Chapter_20.qxd 28/09/2004 15:57 Page 481 20: Spinal Injuries

Surgery 2011 Penetrating injuries involving the spinal cord With the exception of wound excision and delayed primary closure, operative treatment of these cases should not be undertaken in anything other than a fixed specialist facility. The role of surgical management remains controversial. Possible indications include: Spinal instability. Progressive neurological deficit. Persistent CSF leak. Decompression of partial cord injuries. Prevention and treatment of infectious complications. Retention of a foreign body in or around the spinal cord rarely causes problems. Indications for removal include: • Infection. Early fixation can help with the • Foreign body reaction. mobilisation and transfer of complex, • Copper or lead foreign body unstable spinal in a join or disc space. injuries but requires expertise. • Radicular pain where the foreign body is demonstrated to be compromising the root.

2012 Non-penetrating injuries Surgical stabilisation should be delayed pending appropriate radiological investigations.

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Peripheral Nerve Injuries

Introduction

2101 Peripheral nerve damage occurs as a result of penetrating or blunt trauma. It is frequent in war fighting and can have a major effect on functional outcome. Partial loss of nerve function is common. Nerve injury is rarely isolated and commonly associated with vessel, bone and soft tissue damage. Careful, early management optimises recovery. Where necessary, nerve repair should be carried out at a Role 3 or 4 facility but, only under ideal conditions, which are: • Following excision of all devitalised tissue. • An absence of infection. • A well vascularised wound environment. • A skilled surgeon with appropriate equipment.

Pathophysiology

Anatomy 2102 The structure of a peripheral nerve is illustrated in Figure 2101.

Classification of nerve injuries 2103 This is based on the degree of anatomical damage and the potential for regeneration.

2104 Neurapraxia (First degree injury). Stretching or distortion of the nerve due to blunt, blast or high energy-transfer injury results in a 483 Chapter_21.qxd 28/09/2004 15:57 Page 484 21: Peripheral Nerve Injuries

Epineurium Perineurium Fascicles

Axon Myelin Node of Ranvier

Neurilemma Schwann cell nucleus

Fig 2101 Structure of a nerve.

physiological paralysis. The neurilemma sheath (Schwann cell layer) and the central axon remain in-continuity and degeneration does not occur. Recovery time varies between several hours up to twelve weeks and is usually complete.

2105 Axonotmesis (Second - Fourth degree injury). The axon is severed, but the structure of the nerve is maintained by the intact neurilemmal sheath, perineurium or epineurium. A typical example of axonotmesis is radial nerve palsy after fracture of the humerus. Initially, there is degeneration of the axon distal to the division (Wallerian degeneration), followed by regeneration. A spray of processes grows from the proximal end of the axon. When one of these finds its way into the distal neurilemmal sheath, the others regress. The process grows down the tube at a rate of 1-2mm per day. Eventually, there 484 is regeneration of the end organ. Chapter_21.qxd 28/09/2004 15:57 Page 485 21: Peripheral Nerve Injuries

The damage to the supporting connective tissue layers and the degree of intraneural fibrosis, dictate the extent of axonal regrowth and eventual recovery: • Second-degree injury: no intraneural fibrosis. Recovery may be near complete. • Third-degree: moderate fibrosis. • Fourth-degree injury: dense fibrosis blocking any axonal fibre regrowth. Regeneration is only possible if the affected segment is excised and the nerve repaired or grafted.

2106 Neurotmesis (Fifth-degree injury). The nerve is completely divided. The ends tend to retract causing a variable gap. Degeneration occurs distal to the injury. The nerve must be repaired if any recovery is to take place; results are better if this is carried out early. Even after the most skillful repair, recovery is affected by incorrect rewiring i.e., regenerating sensory and motor nerve fibres make connections with organs which they did not previously innervate.

Management

Recognition of injury Test and record 2107 Find out the mechanism of injury and, function of the in the case of penetrating injury, factors that may major peripheral indicate the path of the missile. Certain long bone nerves before fractures (e.g., humerus+radial nerve, femur+sciatic anaesthesia or transfer. This takes nerve) and fracture-dislocations (e.g., elbow+ulna only seconds to do. nerve, knee+common peroneal or posterior tibial Nerve injury is nerve) are associated with nerve damage. Be easily missed in suspicious when dealing with penetrating injuries the unconscious casualty. and high energy-transfer wounds in the vicinity of important nerves. Because the major arteries and peripheral nerves usually accompany one another, injury to one suggests damage to the other. 485 Chapter_21.qxd 28/09/2004 15:57 Page 486 21: Peripheral Nerve Injuries

Compare findings in both limbs. Look for: When carrying out the plastic pen • Loss of sensation - for pure sensory or mixed test, always try an nerves. Test with a pin. Two-point discrimination uninjured finger first so as to get a feel is useful in assessing significant nerve injury for the normal and monitoring recovery of digital nerve injuries. amount of All that is required is a bent paper clip. In the adherence. finger pulp, normality is approximately 4mm. • Loss of sweating - sensory nerve only: this is demonstrated in hand injuries by assessing adherence: The plastic pen test. A plastic pen is gently stroked along the skin on each side of the finger. There is normally slight adherence. Following nerve damage, if there is no sweating there is no adherence. • Loss of motor activity - pure motor or mixed nerve. Following neurapraxia, there is typically paralysis of the muscle groups innervated by the nerve; a degree of sensation and autonomic function is preserved. After axonotmesis and neurotmesis, all power, sensation and autonomic function are lost. Diagnosis of nerve injury can be difficult and major defects are frequently missed. When in doubt, re-examine with 48 hours of injury. At Role 4, MRI can be used to determine the continuity of a peripheral nerve. Nerve conduction studies and electromyography are used to determine the functional status of a segment of nerve. Myelography may be helpful in assessing avulsion from the cord following brachial plexus injury (2130).

Specific nerves Brachial plexus 2108 Injuries are due to violent traction or penetrating trauma. Nerve roots may be avulsed from the spinal cord. All parts of the plexus can 486 undergo any of the injury types described in 2103. Chapter_21.qxd 28/09/2004 15:57 Page 487 21: Peripheral Nerve Injuries

C3

C4

T3

T2

C5

T1

C8

C6

C7

Main Branches Cords Divisions Trunks Nerve Roots

C5 r ppe U C6

ior er nt l a ra e C7 te Middl La r s terio ou os C8 ne P er ta l Low cu dia D lo Ra or 1 u ry ri c a nte s ill a u x ial M A ed M

n ia d e M

r lna U

Fig 2102 Dermatomes of the arm and structure of the brachial plexus.

The classic sites for damage are at the C5-C6 (Erb's Palsy) and C8-D1 roots (Klumpke's Palsy - rare). In the former, there is loss of abduction and external rotation at the shoulder, elbow flexion and forearm supination: the arm adopts the 'waiter's tip' position. 487 Chapter_21.qxd 28/09/2004 15:57 Page 488 21: Peripheral Nerve Injuries

Fig 2103 Median nerve: testing motor function.

The effects of injury may range from paralysis of muscle groups and areas of anaesthesia, through to a useless, flail limb. The affected parts of the brachial plexus can be diagnosed by assessing dermatomes and motor and sensory loss in the peripheral nerves of the upper arm (Table 2001, Figure 2102). Look for swelling in the posterior triangle of the neck, a Horner's syndrome (indicates preganglionic injury) and fractures of the clavicle, ribs and vertebrae.

Axillary nerve 2109 The axillary nerve winds round the neck of the humerus and is injured following shoulder dislocation. Feel for contraction in the deltoid muscle on abducting the arm. Test pinprick sensation in the outer shoulder - the skin overlying the lower deltoid. The majority of cases recover spontaneously.

Musculocutaneous nerve 2110 Assess for absence of elbow flexion and loss of sensation along the lateral forearm. 488 Chapter_21.qxd 28/09/2004 15:57 Page 489 21: Peripheral Nerve Injuries

Median nerve

Radial nerve

Ulna nerve

Fig 2104 Testing sensation in the hand.

Median nerve 2111 In the upper arm, the median nerve is associated with the brachial artery (Figure 1020); damage to one is likely to affect the other. The nerve is classically injured at the elbow or wrist. Assess motor function by asking the casualty to touch the tip of the little finger with their thumb (Figure 2103). Test the power of finger flexion in the index and middle finger. Can the casualty feel a pinprick at the tip of this index finger (Figure 2104)?

Ulnar nerve 2112 The ulnar nerve passes behind the medial epicondyle at the elbow and continues distally in the forearm with the ulnar artery (Figure 1022). It is vulnerable at both sites. Assess motor function by asking the casualty to spread their fingers against resistance (Figure 2105) or to grip a piece of paper between them. Test sensation in the tip of the little finger with a pin (Figure 2104).

Radial nerve 2113 The radial nerve passes in a grove behind the mid humerus and is at risk following missile injuries. If motor function in the hand is affected 489 Chapter_21.qxd 28/09/2004 15:57 Page 490 21: Peripheral Nerve Injuries

Fig 2105 Ulnar nerve: testing motor function.

(wrist drop), the injury is above the elbow. If only sensation is lost then injury is below the elbow. Ask the casualty to extend their wrist and fingers (Figure 2106). Because of overlap, test pinprick sensation over the first dorsal web space (Figure 2104). Recovery is usually good, either after conservative management or repair.

Femoral nerve 2114 The femoral nerve passes under the inguinal ligament lateral to the femoral artery (Figure 0702), beyond which it divides into multiple, superficial branches. Damage results in paralysis of the quadriceps muscles, loss of knee extension and anaesthesia of the anteromedial thigh. Sciatic nerve 2115 The sciatic nerve may be damage along its course by a pelvic fracture, posterior dislocation of the hip, femoral fracture or a compartment syndrome of the thigh (Figure 2107). Assessment is as for the peroneal and posterior tibial nerves. Prognosis is poor, especially for proximal lesions.

Peroneal nerve 2116 The peroneal nerve is at risk from lateral 490 blows to the knee, badly applied POP and traction Chapter_21.qxd 28/09/2004 15:57 Page 491 21: Peripheral Nerve Injuries

Fig 2106 Radial nerve: testing motor function.

splints, or a lower leg compartment syndrome (0906). Paralysis causes foot drop. Test the casualty's ability to dorsiflex their ankle against resistance (Figure 2108) or instruct them to walk on their heals. Sensation is lost in the area indicated in Figure 2109.

Posterior tibial nerve 2117 Test the casualty's ability to plantar flex their ankle against resistance (Figure 2108) or instruct

Sciatic nerve

Common peroneal nerve

Posterior tibial nerve

Fig 2107 Course and branches of the sciatic nerve. 491

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Peroneal nerve Posterior tibial nerve

Fig 2108 Testing motor function of the peroneal and posterior tibial nerves.

them to stand on tiptoe. Sensation is lost in the area indicated in Figure 2109.

Initial management of penetrating wounds Management of 2118 General wound management is described in nerve injuries begins with appropriate Chapter 5. Nerve repair in the field is generally casualty and wound delayed until a 'second look' procedure (0510). management. Management of ABC • During wound excision, identify the nerve ends. takes priority. Tack them with a fine nylon suture to aid subsequent identification.

The effects of • Prevent retraction of the nerve ends with nerve damage a loose, intervening suture, or fix them to can sometimes be helped by tendon adjacent tissues. transfer or joint • Often, the nerve will be swollen and discoloured arthrodesis. but in continuity. Open the sheath longitudinally Keep manipulation without damaging the local blood supply. Trim to a minimum so as obviously damaged fascicles, but leave partially to reduce scarring damaged tissue alone. Mark the site of injury. and subsequent surgical difficulties. • Keep the wound moist with saline or Povidone iodine soaks during surgery. At all stages, cover the exposed nerve with soft tissue, otherwise it will dry out. This may require mobilisation of a flap. • Analgesia (Figure 0701). • Keep injured limbs elevated. Immobilise using 492

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Superficial peroneal nerve Deep peroneal nerve Tibial nerve

Fig 2109 Testting sensory function of the peroneal and posterior tibial nerve.

a Plaster of Paris slab in a position of function. Examples include: a cock-up splint to prevent wrist drop and a right-angle splint in casualties with foot drop. This minimises muscle and joint contractures and reduces pain. • Document which nerve(s) are injured, the presence and width of any gaps found at surgery, details of tacking sutures and associated injuries. • Whenever feasible, the joints of the injured limb should be mobilised through their entire range (arcs) of movement. This keeps the muscles from shortening and the joints supple.

Nerve repair 2119 The aim is to restore the continuity of motor and sensory fascicles in the proximal segment with the corresponding fascicles in the distal segment.

Timing of surgery 2120 Early primary repair provides the best results. It may sometimes be justified in the field following sharp, penetrating trauma that is less than 6 hours old, with minimal contamination and a stable 493

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casualty. Repair should be carried out by a trained surgeon, in a bloodless field and with magnification to ensure precise suture placement. Combat casualties are often unstable and have considerable soft tissue trauma. Nerve surgery is delayed until they are fully resuscitated, inflammation has abated and the surrounding soft tissues have healed. This can range from 2 weeks to 6 months. Another consideration is that there can be nerve damage both proximal and distal to the site of trauma; this may not be immediately apparent.

Consequences of delayed repair 2121 These include: • Adherence of nerve ends to surrounding tissues. • Proximal neuroma formation. • Epineureal thickening, (its presence aids suture placement). • The need for further nerve excision back to healthy fascicles, thus increasing the likelihood of nerve grafting. • Poorer outcome compared to immediate repair.

Principles of repair 2122 These are: Remember, too much dissection • Mobilisation of the nerve ends from surrounding of the nerve can tissues. This is likely to require a tourniquet. deprive it of its vascularity and Look for and preserve any undamaged branches. reduce its capacity to regenerate. • Unless cleanly divided without neuroma formation, cut the nerve ends back until healthy tissue is encountered (Figure 2110). • Under magnification, align the ends using surface vessels, angle of division or fascicular arrangement, as a guide. 494 Chapter_21.qxd 28/09/2004 15:57 Page 495 21: Peripheral Nerve Injuries

Fig 2110 Preparing the nerve ends for repair. End to end repair.

• Approximation of the nerve ends with minimal Secondary nerve tension using fine monofilament sutures placed repair takes time. Frequently, there is in the epineurium (6/0 for the sciatic nerve, 8/0 severe scarring and for median, ulnar and radial nerves and 9/0 for distortion of anatomy digital nerves), using an atraumatic needle. making identification Leave two ends long to act as stay sutures. and dissection difficult. Attempts Usually, 4-6 sutures placed equidistant around at reconstruction the circumference are sufficient (Figure 2110). may make matters NB: the epineurium does not readily hold sutures worse. Sometimes, in the early stages after injury. amputation is a better option. • Reduce tension by flexing proximal and distal joints. It is seldom possible to gain significant extra nerve length by extensive mobilisation. 495

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Fig 2111 Cable graft.

If in doubt, perform nerve transposition for example, the ulnar nerve from behind the elbow, or grafting (2123). Occasionally, bone shortening may be justified. Ruptured tendons can be differentiated • Provide soft tissue cover. from nerves by traction, this • Postoperative splinting with appropriate will reveal their distal flexion for 3-6 weeks. The angle can be attachment. Look for reduced as healing progresses. Provide the fascicle bundles in the cut nerve. regular passive exercising.

2123 Nerve grafts A graft is required when the ends cannot be approximated to allow a tension-free repair despite mobilisation and/or transposition. Common sources A nerve graft must are expendable nerves, such as the sural nerve have a suitable graft lateral to the Achilles tendon - mobilised through bed. Free grafts in a small, transverse incisions - and the medial and suitable bed acquire excellent circulation lateral cutaneous nerves of the forearm. within a few days. • The graft is cut 15% longer than the gap in the nerve to allow for subsequent shortening. • Cable grafts are used for larger nerves. Several lengths of nerve are laid alongside each other, to make up the thickness required for a larger nerve (Figure 2111). The drawback is that the cables are in contact with each other rather than with a vascular bed.

Monitoring recovery 2124 Nerve regeneration usually begins around four to six weeks after repair and progresses 496 at a rate of 1-2mm per day. Chapter_21.qxd 28/09/2004 15:57 Page 497 21: Peripheral Nerve Injuries

• Motor recovery is first seen in muscle groups nearest the site of injury or repair. • Sensory recovery is initially manifest by sweating, followed by crude touch, a useful, two-point discrimination distance (2107) and lastly, fine touch.

2125 Tinel's sign Commence firm digital percussion in a distal-to-proximal direction over the nerve towards the site of repair. An electric shock sensation in the territory of the nerve is a positive Tinel's sign. Regularly monitor distal progression.

Factors influencing recovery 2126 Preoperative • Age: younger casualties do better. • Type of nerve: pure sensory or motor do better than mixed nerves. Some nerves recover more quickly than others: digital > radial > median > ulnar. Warn the casualty: • Type of injury (e.g. neurapraxia). Sharp cuts lack of sensation during recovery risks give better results than crush or avulsion. injury from extremes The presence of a gap impairs recovery. of temperature, Proximal lesions do worse than distal ones. pressure and sharp objects. Because of • Timing of repair: the earlier the repair, the better the lack of sweating the prognosis. regularly apply moisturising cream. • Presence of infection and associated injuries.

2127 Operative • Meticulous haemostasis. • Tension free repair. • Gentle handling. • Precise suture placement. 497 Chapter_21.qxd 28/09/2004 15:57 Page 498 21: Peripheral Nerve Injuries

2128 Postoperative • Splinting. • Physiotherapy. • A motivated casualty.

Management of closed nerve injuries 2129 Closed nerve injury may occur at the time of wounding (primary) or during treatment (secondary e.g., fracture reduction). Because the severity of injury may not be clear, they can pose management difficulties: Persistent pain • In primary, closed nerve injuries, where or paraesthesia operative management is unnecessary for in the distribution of a nerve is likely fracture treatment, early exploration of the nerve to be due to is rarely indicated. Monitor regularly for signs compression of impaired nerve function. Spontaneous nerve (e.g., scar tissue, recovery following isolated nerve injuries callus) and is an indication associated with closed fractures occurs in 85% for exploration (open fracture 65-70%). If there are no signs following of regeneration after 2-3 months, the lesion closed injury. is likely to be degenerative. Exploration should be considered. • If surgery is required for internal fixation, fracture reduction or vascular repair, take the opportunity of exploring adjacent nerves. • In difficult cases, MRI scans can be used to determine the continuity of a peripheral nerve. If the Compound Nerve Action Potential (CNAP) is absent when performing Nerve Conduction Studies in the early months after a closed nerve injury, resection and repair of the nerve is required. Where CNAP is present but altered, consider neurolysis of the whole nerve, or split repair of damaged fascicles. • In secondary, closed nerve injuries, nerve exploration is mandatory. 498 Chapter_21.qxd 28/09/2004 15:57 Page 499 21: Peripheral Nerve Injuries

Management of brachial plexus injury 2130 Transfer to a specialist unit assess using MRI (2107). Early exploration may be beneficial. The overall outlook is often poor.

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Burns

Introduction

2201 Burns are distressing and challenging Use of BATLS injuries. Lack of familiarity and the unpleasant principles offers nature of the injury, often distract the carer from the best chance following BATLS principles. Accurate assessment, of survival from appropriate resuscitation and timely transfer all burn injury. optimise recovery. Modem burn care is based on large, specialised Up to 50% of battlefield burn centres staffed by multidisciplinary teams. The casualties will resources required to deliver this specialist care have other are substantial and are not appropriate further non-burn injuries. forward than role 4. The civilian standard is to deliver the burn victim to such a facility within six hours. Current military practice is to stabilise the casualty then transfer to definitive care as soon as possible. In most operational deployments, there will be a requirement for non-specialists to provide burn care with fewer resources, than those available in a UK-based burn unit. They are also unlikely to achieve casualty transfer to a specialist unit within 6 hours. In all environments, treating a severe In the 1982 burn draws heavily on resources: a small number Falklands conflict, of casualties can overwhelm a facility. In this 34% of those injured situation, clinical management may involve on HM ships, sustained burns, difficult triage decisions. compared to 14% of the total UK casualties. Burns Epidemology were seen in 10% of injured troops in 2202 On military exercises or during transition the 1973 Yom Kippur war, but in up to 70% to war, the majority of burns encountered amongst of Israeli tank crew personnel will be accidental, often due to incorrect casualties. 501

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Although not use of equipment and ignoring safety procedures. fire proof, standard UK combat clothing The variety of injuries will be similar to those seen offers protection in civilian practice. against burning and does not readily In war fighting, burn injury rates vary with the type ignite. The main area of conflict. Traditional anti-personnel munitions tend of risk continues to not to cause significant burns in survivors. Certain be flash burns to weapons are designed to inflict burns, Napalm, exposed skin, namely face and weaponised phosphorus and flame-throwers, are hands. Future some examples. Munitions used to destroy buildings, strategies to protect vehicles, aircraft and ships may cause burns, exposed skin may often due to secondary ignitions. Thermonuclear include lightweight garments, goggles detonations will result in large numbers of burn and thermal casualties (0224). Newer blast weapons, such barrier creams. as thermobaric explosives, produce significantly higher amounts of heat, but their impact has yet to be encountered (0221).

Pathophysiology

Systemic injury 2203 Direct thermal injury causes progressive cell death as temperatures rise above 45°C. Cell death is almost instantaneous above 60°C. Heat is also conducted into surrounding tissues, causing sub-lethal inflammatory injury. Features include increased capillary permeability and loss of fluid from the intravascular space. The clinical impact of the inflammation evolves over several hours and is related to the total volume of tissue injured. This is best expressed as the percentage of total Early cooling body surface area burned (%TBSAB): of a burn wound can reduce the • Superficial burns produce erythema with no magnitude of the effect on capillary leakage; they should not local inflammatory be considered when calculating the %TBSAB. injury. • Injuries over 15% TBSAB (10% in children) cause sufficient loss of intravascular fluid for compensatory mechanisms to be overwhelmed. 502 Additional fluids need to be administered to prevent shock developing.

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• Injuries above 25-30% TBSAB cause massive Over 25% TBSAB can cause a life activation of inflammatory mediators, resulting threatening systemic in development of a Systemic Inflammatory inflammatory Response Syndrome (SIRS). This is a response. progressive process that continues to develop for several hours after the burn. The clinical signs of SIRS can be delayed. Toxins released from the burn wound further stimulate the SIRS. In the healthy, excessive i.v. fluid administration can be compensated for by an increased urine output. In the burn victim, too much fluid results in excessive oedema.

Inhalation injury Inhalation injury is not a single entity, it consists of a variable combination of: 1. Airway burn 2204 This is caused by inhalation of hot gases from flame, smoke and steam. The injury is usually confined to the upper airways. There is intense mucosal congestion, followed by severe oedema There is no way with the risk of obstruction. The swelling develops to quantify the severity of an over several hours and is maximal between 12 and inhalation injury, 36 hours. The laryngeal mucosa eventually becomes its presence ulcerated and breaks down leading to secondary significantly infection and perichondritis. worsens the prognosis following 2. Lung injury a burn. 2205 If the products of combustion are inhaled into the lower airways, they dissolve into the fluid lining the bronchial tree and alveoli. This leads to a Note that in the presence of carboxy- chemical injury to the lungs which produces varying haemoglobin, pulse degrees of pulmonary failure, often delayed by hours oximeter readings or even days. are unreliable indicators of oxygen saturation (%Sa02). 3. Systemic toxicity 2206 Absorption of the products of combustion into the circulation through the alveoli leads to 503 Chapter_22.qxd 28/09/2004 15:57 Page 504 22: Burns

systemic toxicity. The most important agents are carbon monoxide and cyanides. This is the most common cause of death due to fires in enclosed spaces. Carbon monoxide competes with oxygen for binding to haemoglobin, with 240 times the affinity. It displaces oxygen, effectively causing hypoxaemia. It also binds to the intracellular cytochrome system, causing abnormal cellular function: • A low level of carboxyhaemoglobin (<10%) causes no symptoms and can be found in heavy smokers. • Above 20%, the casualty experiences fatigue, nausea and impairment of higher mental functions. • Levels above 40% lead to progressive loss of neurological function. • Death occurs with levels over 60%.

Cutaneous injury Classification of the burn wound is purely descriptive and indicates the depth involved (Figure 2201).

Epidermal burns

Pain levels are not 2207 Cause erythema alone, the most common a reliable indicator being sunburn. Healing is rapid and spontaneous. of burn depth. Erythema is not included when calculating %TBSAB.

Partial thickness burns 2208 The superficial dermis is affected, it becomes wet and blistered. There is marked erythema which blanches on pressure; capillary refill remains intact. Deeper skin adnexal structures survive. If managed correctly, a partial thickness burn should heal in less than 2 weeks.

Deep dermal burns 504 2209 The skin is darker red and does not blanch. Chapter_22.qxd 28/09/2004 15:57 Page 505 22: Burns

Erythema

Most epithelial elements intact Superficial partial thickness

Only deep Deep parts of sweat partial glands survive thickness

No epithelial Full elements thickness remaining

Fig 2201 Cross section of skin to illustrate the structures affected by increasing depth of burn.

This 'fixed staining' is caused by damage to deeper Burn wounds are blood vessels. Deep dermal burns rarely heal within not homogenous in two weeks and often require skin grafting. and a mixed pattern may be seen.

Full thickness burns 2210 There is total destruction of the dermis leaving a firm, leathery necrotic layer known as eschar. The appearance can be 'waxy white' or 'lobster red'. Soot or charred tissue may mask the true appearance. Surgery is required except when the area of burn is small. Deep dermal and full thickness burns can constrict deeper structures, particularly if the burn is circumferential. Around the torso, this can restrict respiratory movement. In the limbs, a similar picture to compartment syndrome may develop. Surgical release of the constriction (2235) is indicated.

2211 Burn wounds are dynamic and the inflammatory process can cause progression of 505 Chapter_22.qxd 28/09/2004 15:57 Page 506 22: Burns

depth. Burn depth has little bearing on resuscitation, but will dictate later wound management. Attempts to accurately define burn depth in the first few hours are unnecessary.

Management

First aid Effective first aid can significantly Immediate priorities improve outcome. 2212 These are: Stop the burning process. Continue to • Stop the burning process. This is best achieved cool the burn, but warm the casualty. by dousing the effected area in cold water and removing smouldering clothes and those soaked in scalding fluids. • Manage ABC. • Remove all potentially constricting items such as finger jewellery and wrist watches. • Loosen boots and belts. • If chemical burns are suspected, decontaminate (0230). Chemical powder is best removed prior to irrigation.

Cooling 2213 Further cooling of the burn wound for at least twenty minutes after injury, is beneficial. This can moderate local inflammation and has an analgesic effect. Cool water should be used, preferably flowing. Very cold water and ice cause local vasoconstriction and may worsen the injury. Protracted cooling may lead to systemic hypothermia.

Dressings 2214 If available, Clingfilm™ should be laid on to the burn wound as soon as possible (be cautious in chemical burns - see below). Do not wrap it around 506 Chapter_22.qxd 28/09/2004 15:57 Page 507 22: Burns

a burn, this can cause constriction; apply it in longitudinal, overlapping strips. Other options are clean linen or clothing. Soaks can then be placed over the initial dressing and the casualty kept warm.

Additional measures 2215 Burns are painful and the casualties are often terrified. Reassure them, give opiate analgesia (0706), oxygen (0317) and obtain i.v. access (0333).

Estimate the size of the burn 2216 Use the process of serial halving: • Over half the body surface area burnt. • Between half and a quarter burnt. • Between a quarter and an eighth burnt. • Less than an eighth burnt.

Transfer to Role 2 or 3 2217 Priorities are: • Any suggestion of inhalation injury = T1 • Burns over a quarter of the body = T1 • Burns between a quarter and an eighth = T2 • Burns less than an eighth = T3

Management at Role 1 and Role 2 Use standard BATLS principles.

Airway 2218 Airway obstruction may not be evident when the casualty is first seen. It is important to anticipate those at risk: • A history of exposure to fire and smoke in an enclosed space. 507

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• Exposure to blast. • Collapse, confusion or restlessness at any time. • Hoarseness or any change in voice. • Harsh cough. • Stridor. • Flame or steam burns to the face.

A high index • Singed nasal hairs. of suspicion is the • Soot in saliva or sputum. key to diagnosing inhalation injury. • An inflamed oropharynx.

2219 Treatment • Administer oxygen (0317). • If any degree of upper airway obstruction Deep circumferential is present, a secure airway is mandatory torso burns require ( NB: swelling is likely to deteriorate). emergency The majority of cases will be conscious and escharotomy. endotracheal intubation will not be possible without anaesthetic assistance. Where this is unavailable in forward areas, perform a surgical airway under LA (0305). • If it is considered safe to transfer the casualty unintubated, they should be nursed sitting up. Note: i.v. dexamethasone is not considered of value in this situation and is certainly not a substitute for a secure airway!

Breathing

A terrified casualty 2220 The pulmonary manifestations of burn injury gasping for air rarely occur early. Compromise of respiration occurring may have a blast soon after injury may be due to restriction of chest lung injury. excursion by a deep circumferential torso burn - perform an emergency escharotomy (2235).

508

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Circulation If hypovolaemic shock is evident 2221 Hypovolaemic shock secondary to a burn early after burning, takes some time to produce measurable physical exclude other injuries. A history signs. If the burn victim is shocked early, other of a blast, vehicle causes should be excluded. collision or a fall whilst escaping • Start fluid resuscitation with crystalloid the fire, should independent of the severity of burn (0333). raise suspicion It is possible to cannulate through burnt skin of other injuries. but this is generally avoided. • If necessary, use venous cut-downs (3017), intraosseous or, as a last resort, central routes for fluid administration (2547).

Disability 2222 A reduced level of consciousness, confusion and restlessness, normally indicate hypoxia secondary to an inhalation injury. Do not overlook the possibility of other injuries or drug and/or alcohol ingestion contributing to the casualty's reduced mental state.

Exposure / Environment

2223 The entire body surface area should be Hypothermia is a inspected for burns and other injuries. Unwrap one significant risk during limb at a time to avoid excessive loss of heat. It may the management of burns. be possible to assess the burn without removing previously applied Clingfilm™. Ensure no constricting items of clothing remain, including boots and belts. If possible, keep the ambient temperature high.

Other interventions

2224 These include: Burns are initially sterile and infection • Analgesia (Figure 0701). is uncommon for the first few days. • If available, measure FBC, U&Es and blood gases.

• In uncomplicated civilian-type burns, there is no 509

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requirement for antibiotic prophylaxis. On the battlefield, assume there is wound contamination and administer antibiotics (0816). • Insertion of a nasogastric tube and urinary catheter will be required for burns >20% TBSAB. • Reassess the casualty's ABCD and perform a full secondary survey.

Initial specific burn management Beyond keeping Assessment a patent airway and delivering the 2225 Regularly reassess casualties with maximally achievable oxygen suspected inhalation injury. concentration, there is little that can be Estimate the size of the burn done for those with inhalational burns 2226 Accurate assessment is impractical at Role without critical care 1 and Role 2. Aids to estimating the %TBSAB are facilities. • Serial halving (2216). • 'Rule of Nines' (Figure 2202). • In very large burns, it is often easier to work out how much is not burnt. • The palmar surface of the casualty's hand, including the fingers, equates to approximately 1% TBSAB and can be used to estimate small areas of burn. At this stage it is not necessary to evaluate burn depth, apart from identifying circumferential burns and considering the need for emergency escharotomies (2235).

Accurately calculating %TBSAB Calculate the fluid requirements is difficult at Role 1 and 2. Make an 2227 Administer i.v. fluids above normal estimate. Do not requirements to prevent burn shock in injuries greater worry about than 15% TBSAB (10% in children). An estimate of accurately assessing the likely volume of crystalloid needed in the first 24 burn depth. 510 hours is made using the formula: 22: Burns 511 1% 9% 18% Front 18% Back 1% 9% 14% 18% 9% 18% 18% Front 18% Back 18% 14% 9% 9% Fig 2202 Rule of nines in children and.adults. Chapter_22.qxd 28/09/2004 15:57 Page 511 Page 15:57 28/09/2004 Chapter_22.qxd Chapter_22.qxd 28/09/2004 15:57 Page 512 22: Burns

• Volume needed in first 24 hours (mls) = 2 x Weight (kg) x %TBSAB • In children = 3 x Weight (kg) x %TBSAB The need for fluids starts at the time of injury. Half this volume is given in the first eight hours from injury then the second half in the following 16 hours. Other fluid requirements are not accounted for in this regimen. Administer additional fluids where indicated for losses due to other injuries and normal daily maintenance. Hartmann's or Ringer's lactate solution is recommended. Normal saline can be used if necessary, but will cause more disturbance to electrolyte balance.

2228 Example:

The formula is A 75 kg Chef spills boiling water over his combat a guide only. trousers at 0600. He arrives at Role 1 at 0630 and is Monitor the found to have mixed depth burns to both his legs with individual's response and adjust as erythema of his buttocks and perineum. The TBSA necessary. burn is estimated as 36%. By the time he has been assessed, it is 0700. • Volume required: 2 x 75kg x 36% = 5,400 mls in 24 hours. • Half required in first 8 hours after injury = 2,700 mls by 1400.Time now 07.00 = 385 mls/hr of Hartmann's until 1400. • Second half required in subsequent 16 hours = 170 mls/hr of Hartmann's from 1400 until 0600 tomorrow.

Monitoring fluid balance 2229 The calculated volume is an initial guide only. It is essential to monitor the individual's response. Keep an accurate fluid balance record.

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administration is urine output. Aim to keep the urine output between 0.5 - 1 ml/kg body weight/hour. This should be doubled for children. • Do not be afraid to adjust the fluid input to keep the urine output within these limits. Large, full thickness burns and those with an inhalation injury, often require very large volumes of fluid. It is equally as important to reduce fluid administration when indicated.

• Use pulse oximetry to monitor %Sa02 and pulse rate. Carbon monoxide poisoning can give anomalously high %Sa02 readings.

Dressings 2230 Ensure burnt areas are covered with Clingfilm™, laid on, not wrapped. Hands can be placed in plastic bags. Moistened linen with holes cut for the eyes and mouth can be used to cover the face. Keep the casualty warm.

Transfer to Role 3 2231 Priorities are: • Inhalation injury = Tl A • Burns >25% TBSAB =. Tl C • Burns <25% receiving i.v. fluids = T2 • Burns of face, hands, across major joints and perineum = T2 • Chemical or electrical burns = T2 • Other burns = T3

Role 3 At Role 3, reassess 2232 At Role 3, the following interventions take ABCDE and repeat place in addition to all of the above: the secondary survey. • Continued resuscitation. 513

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• Thorough burn wound cleaning. • Accurate burn area assessment. • Appropriate surgery if indicated. • Dressings. • On-going care. • Casualty transfer. • Burn injured casualties need to be kept warm. In advance of their arrival, aim to get the ambient temperature to 28°C, with a high relative humidity This is uncomfortable to work in, but good for the casualty! If this is not possible, warm the casualty directly with an active, warm-air blanket. • Measure FBC, U&Es, glucose and blood gases. For deep burns greater than 20% TBSAB, have cross-matched blood available. • In cases of potential inhalation injury, obtain a baseline chest radiograph and measure carboxyhaemaglobin.

Assess and manage • Evaluate the adequacy of fluid administration. inhalational burns in Key indicators of under-resuscitation are: low conjunction with an urine output, raised haematocrit and an increasing experienced base deficit. Adjust infusion rates accordingly. anaesthetist.

Inhalation injury 2233 Look for features of inhalational injury (2218).

Even in severe • Actual upper airway oedema is an indication inhalation injury for endotracheal intubation or surgical airway. initial blood gas and Those without signs of airway compromise chest X-ray results should be nursed sitting up in a HDU equipped may be normal. for endotracheal intubation. Administer oxygen to keep the PaO2 above 10 kPa. • Fibreoptic bronchoscopy is the investigation of choice. The later manifestations of pulmonary 514 injury can be anticipated if damage to the

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trachea and larger bronchi is seen. Be prepared to instigate pressure support ventilation at the earliest sign of pulmonary failure (2541). The normal clinical picture is of deterioration up to several days following injury. • Chest physiotherapy should be started early The presence of in all cases. The use of pulmonary lavage and an inhalation injury increases the novel ventilation strategies will depend on the volumes of fluid experience of clinicians and equipment available. needed to prevent · Systemic intoxication is treated with general burn shock. supportive measures and administration of 100% inspired oxygen until signs resolve or carboxyhaemoglobin levels fall below 15%. · Current practice suggests there is no role for prophylactic antibiotics (but, see 2224), steroids or hyperbaric oxygen.

Accurate burn assessment 2234 Points include: • Full assessment can be painful. Give adequate analgesia (0704). • Assess large burns in a warmed operating theatre (~30°C) under GA (2232). • Remove first aid dressings and thoroughly clean all involved areas with copious volumes of warm, aqueous-based antiseptic solution. All blister roofs, loose skin, debris and soot should be removed. This has to be a vigorous physical process; gentle dabbing of the burn is ineffectual. • Accurately assess the burn once it has been cleaned. Draw the burn areas on a Lund & Browder chart (Figure 2203) and calculate the %TBSAB. Do not include simple erythema. Adjust the fluid requirements accordingly, taking into account the physiological response to fluids already administered.

• Do not worry too much about defining precise 515

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Lund and Browder Chart

AA

1 1

2 13 2 2213

1.5 1.5 1.5 1.5

1.51 1.5 1.5 2.5 2.5 1.5

BB BB

CC C C

1.75 1.75 1.75 1.75

Ignore simple erythema

Relative percentage of body surface area affected by growth

AREA AGE 0 1 5 10 15 Adult A = 0.5 9.5 8.5 6.5 5.5 4.5 3.5 B = 0.5 of one thigh 2.75 3.25 4 4.5 4.5 4.75 C = 0.5 of one leg 2.5 2.5 2.75 3 3.25 3.5

Region % Superficial Head Deep Neck Ant. Trunk Post. Trunk Right Arm Left Arm Buttocks Genitalia Right Leg Left Leg Total Burn

Fig 2203 Lund and Browder Chart.

burn depth but identify deep areas that may cause circumferential constriction. If not already done, this is the time to perform escharotomies 516 (2235). Chapter_22.qxd 28/09/2004 15:57 Page 517 22: Burns

Surgery 2235 Complicated wound interventions are not appropriate until definitive care at Role 4. Early burn wound excision is common practice in the civilian setting but is time and resource consuming. In the Perform limb field, the only burn-specific procedure required escharotomies is escharotomy. under controlled conditions in the The necrotic layer of deeply burnt skin is known as operating theatre. eschar and is firm and unyielding. As oedema forms in the deeper tissues, the eschar resists swelling and tissue pressure rises. When circumferential, this can compromise perfusion and, in the torso, restrict ventilation. Urgent surgical division of the eschar is then indicated: • Escharotomy is rarely required within the first 2 hours. • Unless there is interference with respiration, it is best to perform the procedure under GA in an operating theatre. • Use cutting diathermy to carefully incise the wound until the constriction is released. Continue this along the full length just into unburnt tissue. Slashing down into unburnt fat is unnecessary. The lines of election for escharotomies are shown in Figure 2204. As most normal • Take care to avoid the ulnar nerve at the elbow ventilation is diaphragmatic, and peroneal nerve around the fibular head. it is important to • Dorsal hand and mid-lateral finger releases ensure the horizontal torso release is over may be needed. the upper abdomen following • Because of the need to extend them into healthy circumferential tissue, escharotomy is painful. As with releasing torso burns. a tourniquet, a period of local hyperperfusion follows escharotomy and significant bleeding can occur. Be patient in ensuring good haemostasis. • In cases of high voltage electrical burns and when there has been prolonged delay in 517

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Fig 2304 Escharotomy incisions - dotted lines, avoid crossing joints.

performing escharotomies, compartment syndrome may be encountered (0906). This is an indication for fasciotomies (0908).

Dressings 2236 The burn wound needs to be dressed for comfort and to help prevent infection during transfer. • Apply a 0.5cm layer of cerium in silver sulphadiazine cream (Flammacerium™) directly on to the burn. Cover with a thick layer of bulky, absorbent gauze and hold this in place with Bags for hands are only useful in the bandages or net dressings. An alternative is alert casualty. silver sulphadiazine cream (Flammazine™); this is no longer the treatment of choice. 518

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• If neither of these creams is available, apply a layer of paraffin gauze and cover with Betadine™ or chlorhexidine soaked gauze. Again, cover with a thick absorbent dressing. • Topical creams are suitable for covering the neck, scalp and ears but should not be used for the face. Keep the face moist with plain aqueous cream reapplied regularly. • In the fully alert and co-operative casualty, burnt hands can be placed in plastic bags. A small amount of Flammacerium is applied. For the first couple of days, exudate rapidly collects in the bags and reduces the advantage of the casualty being able to participate in their own care. • In the HDU/ITU, hands are best dressed with Flammacerium and gauze. Palmar splints should be used to keep the wrist extended at 45 degrees, metacarpo-phalangeal joints flexed at 45 degrees and the interphalangeal joints straight.

On-going care 2237 Measures include: • Record hourly fluid balance and adjust fluid input as indicated. A low urine output suggests hypovolaemia. • Measure FBC and U&E at least twice in the first 24 hours. • Severe, deep burns result in loss of red blood cells. Transfuse blood if indicated by the Hb and haematocrit levels. • Breakdown products of destroyed red cells are excreted in the urine and increase the risk of acute tubular necrosis. If dark red pigmentation of the urine is seen, increase fluid input to achieve a urine output of 1.5 - 2mls/kg/hr. Do not use diuretics. 519 Chapter_22.qxd 28/09/2004 15:57 Page 520 22: Burns

• Start nasogastric feeding, ideally, immediately on admission. This helps maintain gut function, lowers the risk of peptic ulceration and may be beneficial in reducing bacterial translocation from the gut. If it is not possible to start nasogastric feeding, give either an H2 antagonist or, proton pump inhibitor to prevent peptic ulceration. • Nurse casualties partially sitting up with arms elevated on pillows to help reduce oedema. Physiotherapy should start early, with the aim of maintaining normal ranges of joint movements. • Once burns have been dressed and the casualty placed in bed, analgesia requirements decrease. Nevertheless, high levels of anxiety remain and good psychological support is important. Anxiolytics can help, along with a balanced analgesia regimen (Figure 0701). NSAIDs should be avoided in the first 24 hours. • Additional fluid requirements extend beyond the first 24 hours. With nasogastric feeding, a standard regimen will provide for the majority of cases. Give 500ml boluses of colloid (10 ml/kg in children) if hypovolaemia becomes apparent. Again, the casualty's physiological response is the main indicator of fluid requirement. • Burn wounds produce a large volume of exudate. The dressings need to be changed when soaked through, or at least daily. Use the same dressing technique.

Infections in burns 2238 Burn wounds are initially sterile but become progressively contaminated, increasing the risk of invasive infection. • Streptococcal and Staphylococcal infections predominate in the first five days (0816), with Gram negative organisms becoming evident 520 beyond this time.

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• The normal systemic response to burn injury includes a tachycardia, pyrexia up to 38.5 °C and a leucocytosis. In large burns there is marked immunosupression, making the diagnosis of systemic infection difficult. Positive surface wound cultures do not necessarily indicate invasive infection. • There is no evidence that prophylactic antibiotics are beneficial in civilian pattern burns. By comparison, battlefield injuries should receive systemic antibiotics (0816). The antimicrobial activity of topical agents is the main strategy for reducing burn wound infection in the field. • If infection is apparent, antibiotics should be given according to microbiological culture and sensitivity results. In cases that are in-extremis, blind therapy should be: • First five days: benzylpenicillin (1.2g i.m./i.v. four times daily) and flucloxacillin (oral/i.m. - 0822; alternatively 0.5-2g i.v. four times daily). • Beyond five days: a third generation cephalosporin e.g., ceftriaxone (1g daily) and gentamicin (2-5mg/kg daily in divided doses every 8 hours).

Special Burns Electrical burns 2239 Passage of electricity through the body produces heat which can cause burns. The type of injury seen depends on voltage and two groups are generally recognised:

2240 Low voltage - under 1,000 volts This includes the normal domestic mains of 240 volts, voltage from field generators and the common industrial supply of 415 volts. Electrocution leads to 521 Chapter_22.qxd 28/09/2004 15:57 Page 522 22: Burns

cutaneous contact burns at the sites of entry and exit of the current. The tissue damage extends through the full thickness of the skin; deep structures immediately under the wounds can also be damaged.

2241 High voltage - over 1,000 volts Entry and exit wounds have a blast component with Following electrical burns, the threshold massive local damage. There may be multiple entry for both escharotomy and exit wounds as the current can arc across joints. and fasciotomy As current flows through the tissues, extensive, deep should be low. damage occurs. Entire muscle compartments can be destroyed, sometimes without involving the overlying The obvious skin. There is a high incidence of compartment cutaneous wound syndrome (0906) due to muscle damage; the of an electrical burn limbs should be regularly monitored for signs will be an understatement of neurovascular compromise. of the true injury. 2242 Management • In both high and low voltage electrocution, the cutaneous burn is an under-representation of the true extent of the injury. Reliance on the normal formula for calculating fluid requirements, may lead to under-resuscitation; monitor urine output carefully. • Urinary excretion of the breakdown products of haemoglobin and myoglobin is common following extensive electrical burns. This produces a risk of renal failure. Prevention is by administering additional i.v. fluids, aiming for a urinary output of 2mls/kg/hour. • Electrocution is frequently associated with other injuries e.g., falls and violent, tetanic muscle spasms. • Cardiac dysrhythmias can occur following passage of current across the thorax. Cardio-respiratory arrest is often reversible and prolonged efforts at resuscitation are justified. 522 In all cases of electrocution, a 12 lead ECG

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should be performed; if normal, there is no benefit in continued cardiac monitoring.

Chemical burns

2243 Contamination and injury to others are Be cautious when serious risks when dealing with chemical burns. using cling film over chemical burns. • All those involved should wear appropriate protective equipment (0228). Decontamination is discussed in 0230. If powder or lumps of the product are visible, these should be removed first. Any clothes or materials from the victim, together with used irrigation fluid, must be treated as contaminated. • Acids produce coagulative necrosis and the eschar helps reduce penetration. Alkalis cause liquefaction and penetration into deeper tissues is more significant. Irrigation for alkali burns should continue longer than for acid burns, at least one hour. (NB: there is increased risk of hypothermia with prolonged irrigation). Once The use the chemical burning process has been halted, of neutralising management is the same as for other burns. agents can cause exothermic reactions • Covering chemical burns with Clingfilm™ will and worsen the burn. Their use is not keep any residual chemical on the skin, where generally it will continue to injure. It is vital to ensure all recommended. traces of the chemical agent have been removed Where possible, prior to applying Clingfilm™. obtain an expert opinion on the • Chemical burns of the eye require prolonged properties of the irrigation. Seek ophthalmic advice (1730). chemical. · Petrol, kerosene and diesel, produce a chemical burn which initially appears superficial but, may progress to full thickness injury. Systemic toxic effects can occur. Treatment is the same as for other chemical injuries.

Phosphorus burns 2244 These are almost exclusively a military 523

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phenomenon. The element spontaneously ignites in air and is prevented from doing so by immersion in water. The majority of phosphorus burns are caused by secondary ignition of clothing and are treated as normal: Removed phosphorus particles • To prevent further ignition of phosphorus must be immersed in imbedded in wounds, visible lumps should water to prevent ignition in the be removed and the area irrigated with water. operating theatre. Soaking dressings are then applied and kept wet until arrival at a surgical facility. • To help identify further particles during wound excision, an ultraviolet lamp will highlight phosphorescence. • Irrigation of the wound with 1% copper sulphate solution will coat fragments with a layer of black cupric phosphide. This reduces the chance of ignition and makes them easier to see. Copper sulphate is toxic and should be thoroughly washed from the wound. It must never be used as part of a dressing.

Vesicant burns 2245 Various chemical warfare agents cause cutaneous burns and are discussed in 0242. • Full decontamination procedures must be carried out before admission to any medical facility. Thorough cleaning, with removal of all blisters is performed (0244). There is usually no active agent in blister fluid. The exception is Lewisite, but this is easily neutralised by using a weak hypochlorite solution. • Dressings and fluid resuscitation are then the same as for thermal burns. • The loss of fluid can be delayed in vesicant burns and the need for replacement starts when blisters appear, as opposed to the 524 moment of exposure.

Blister (Vesicant) Agents: see Chapter 2 Chapter_22.qxd 28/09/2004 15:57 Page 525 22: Burns

• Wound healing is significantly slower than with a comparable thermal injury (0244).

Transfer to Role 4 2246 All but the most minor of injuries necessitates transfer. A high priority is appropriate because there are clear benefits of early surgery. Also, complications of inhalation injury, SIRS and infection become extremely difficult to manage after about five days. Experience has shown that burn victims can tolerate long distance transfer within the first five days. Transfer priorities to Role 4: Inhalation injury = T1 Clinical evidence of SIRS = T1 Burns over 25% = T1 Those having had escharotomies = T1 Deep burns over 5% = T2 Burns of face, hands, perineum = T2 The rest = T3

Burns in Mass Casualty Scenarios

2247 With optimal care, survival with good quality of life is common even in massive burn injury. It is no longer appropriate to arbitrarily choose a certain % TBSAB above which it is assumed care is futile. Nevertheless, the high demand of burn care necessitates careful use of triage when resources are stretched. The factors that significantly reduce survival rates are: • Inhalation injury except for isolated oropharyngeal swelling. • Deep burns over 80% TBSA. • Age > 60 years. 525

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• Significant concomitant illness or injury.

Two or more of the above, should be the first criteria used for allocating a T4 (expectant) triage category (0604). To help reduce use of resources, it is possible to use only oral fluid therapy for burns at least up to 20% TBSA and possibly higher. Moyer's solution or proprietary oral rehydration formulae may be employed. A normal diet, with extra water to drink, is probably as efficacious.

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Principles of Plastic and Reconstructive Surgery

Introduction

2301 Injuries sustained during military operations frequently require the involvement of a plastic surgeon. This chapter focuses on reconstructive techniques of soft tissue wounds that may be applicable in the field. Treatment of trauma to the hand (Chapter 9), peripheral nerve injuries (Chapter 21) and burns (Chapter 22) are covered elsewhere. The aim of reconstructive surgery is to restore form and function. The objectives are: Short term: achieve wound healing. Longer term: achieve functional and aesthetic recovery. Considerations when attempting to achieve wound healing include:

• Management of ABC to maintain tissue Prevent further injury perfusion and minimises further tissue loss. by handling tissues gently, especially • Prevention of infection by wound excision nerves and vessels. (0503), antibiotics (0816) and repair of visceral Place sutures without tension. injury. The use of appropriate techniques of Ligate vessels with wound closure. minimal loss of length -they may be used for future Methods of Wound Closure anastomoses. Maintain nerve length. 2302 Options are summarised Figure 2301. • In a military environment, delayed primary closure is the norm (0503). Primary suture is restricted to areas with an excellent blood 527

Hand Injury: see Chapter 9 Peripheral Nerve: see Chapter 21 Burns: see Chapter 22 Chapter_23.qxd 28/09/2004 16:05 Page 528 23: Principles of Plastic and Reconstructive Surgery

Distant free flap

Regional pedicle flap

Local flap

Skin graft

Primary Closure

Healing by secondary intention

Fig 2301 The reconstructive ladder. Start at the bottom with simple techniques. Methods near the top are retained for more complex cases.

supply for example, the face, scalp and scrotum (0504). • Some hand wounds are closed primarily to avoid exposure of underlying structures. • Skin grafting and the use of flaps to import tissue are usually reserved for use at Role 3 and Role 4. These techniques risk complications and all result in donor site morbidity. Their application other than at Role 4, should be limited to situations where transfer to a plastic surgeon is delayed or impossible.

2303 The following optimise wound healing: • Hydration. • Nutrition. • Warmth. • Rest. • Elevation. • Stopping smoking.

528

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Overview 2304 Points include: • Attempt to cover vital structures such as nerve, tendon, vessel anastomosis and bone, by closing part of the defect. Keep the remaining exposed tissues moist with appropriate dressings. Avoid relieving incisions as these may jeopardise the use of local flaps for later reconstruction. • Split skin graft can be used as a definitive method of wound closure or, as a temporary solution prior to complex reconstruction. It is very effective at preventing desiccation and, in some parts, may 'take'. This will allow healing of the surrounding areas and buy time before definite cover can be arranged. Disadvantages are that it requires technical skill to harvest the graft and results in a painful donor site. • Consider using a flap.

Skin grafts 2305 Skin grafts are the 'grass seeds' of skin replacement and flaps are the 'turf'. A skin graft requires a suitable bed of viable tissue to 'take' by a process of revascularisation. It must be immobilised during the first five days to prevent shearing of the new growth of blood vessels. For optimum graft take the wound must be Paratenon and • Clean. periosteum are kept moist during wound • Free from significant infection. excision as drying will jeopardise any • Well vascularised. future graft take. An ideal bed is healthy muscle or fascia. Grafts will take on paratenon, periosteum, nerve, vessel and 529

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Thin Intermediate Thick

Full thickness skin

Fig 2302 The thickness of various types of skin graft.

deeper tissues, such as dura and omentum. Even if there is exposed bone, a split skin graft can still be used as temporary cover.

Split skin grafts 2306 Different depths of graft can be taken using a dermatome or hand knife, (Figure 2302). The superficial layers of the skin are most commonly harvested (split skin graft) leaving a donor site that heals by re-epithelialisation from deeper adnexal elements, such as hair follicles.

Harvesting the graft 2307 Steps include The quality of harvested skin is • Adjust the dermatome to a setting of 10-12. dependent on both When using a hand knife (e.g., Humby knife), the surgeon and the adjustment is usually done by eye and requires assistant. Do not experience. A simple aid is to insert a size 15 start until you have good 'stretch'. scalpel blade between the skin graft knife and Remove any iodine the base of the instrument. When correctly skin preparation to adjusted, the gap will allow three quarters avoid sticking. of the bevel of the scalpel blade to be admitted. 530 Chapter_23.qxd 28/09/2004 16:05 Page 531 23: Principles of Plastic and Reconstructive Surgery

Fig 2303 Donor sites for harvesting split skin grafts.

• Donor sites are illustrated in Figure 2303. The most common site is the anterolateral thigh. • Stretch the skin while immobilising the soft tissue of the knee and thigh. • The donor area and knife are lubricated using liquid paraffin or aqueous jelly. The skin is separated by a forward and backward cutting motion, rather than trying to advance the knife down the thigh. A hand or graft board is moved in front of the advancing knife to flatten the skin (Figure 2304). The donor skin is separated by either, an upsweep of the graft knife or, by the use of scissors.

Managing the donor site 2308 Points to note: • The donor site should now be covered with fine pinprick bleeding areas. More active bleeding or visible fat indicates that the harvested graft is 531 Chapter_23.qxd 28/09/2004 16:05 Page 532 23: Principles of Plastic and Reconstructive Surgery

Skin hook

Humby skin graft knife

Graft board

Fig 2304 Adjust the knife or dermatome. Stretch the skin and lubricate using liquid paraffin. The skin is harvested by a forwards and backwards cutting motion. A hand or graft board is moved in front of the advancing knife to flatten the skin. too thick. Replace the donor skin and perform a second harvest after adjusting the knife setting. • Dress the donor site using an alginate, paraffin gauze, wool and a crepe bandage. Secure this well, movements of the dressing against the raw donor site can be a source of significant discomfort. • The donor site dressing is left intact for fourteen days. If wound exudate seeps through the dressing, this should be over-wrapped to prevent ingress of bacteria. Change the dressing if there is suspicion of infection.

Applying the graft 2309 Prepare, apply, fix and immobilise: 532 Chapter_23.qxd 28/09/2004 16:05 Page 533 23: Principles of Plastic and Reconstructive Surgery

A

B

C

Fig 2305 A) Technique of meshing a split skin graft. B) fixing it to the wound.C) tying the sutures over foam or cotton wool to hold the graft in place.

• The graft should be fenestrated with a scalpel (Figure 2305) or passed through a mesher. The resultant defects prevent exudate collecting

Random pattern flap

Axial pattern flap

Arteriovenous system Fig 2306 Random and axial pattern flaps. 533

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x

Triangle

Fig 2307 Advancement flap.

beneath the graft and enable a larger area to be covered. • The split skin is secured to the wound using sutures, glue or staples. Apply an overdressing of paraffin gauze and foam (or cotton wool balls). This can be fixed in place by tying the long ends of the sutures over the top to prevent shearing (Figure 2305). The area is then covered with dressing gauze, wool and a crepe bandage. A plaster of Paris splint is used to immobilise joints (0915), where movement might interfere with healing. • Elevate affected limbs to minimise swelling. • The dressing is removed 5 days later. By this stage, the graft should be adherent to the wound when lightly touched and have a pale pink colour. 534

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DEFECT

Pivot point

Backcut Triangle

Fig 2308 Rotation flap. A backcut or triangle can be used to reduce tension.

Skin flaps 2310 Flaps have an integral blood supply, which is either based on a random or axial pattern (Figure 2306).

Random pattern flaps 2311 These rely on basic geometrical principles and must have an adequate breadth to length ratio to ensure good vascularity, (Figure 2307). Usually, these flaps are small and simply redistribute local excess tissue. Common applications are the hands, face and scalp (Figure 1604). Examples are: advancement (Figure 2307), rotation (Figure 2308) and transposition flaps (Figure 2309). 535

Skin Flaps on the Scalp: see Chapter 16 C C F Primary defect 60° DEFECT 120° D F E E B D E B D D Pivot point Loose skin E A A Secondary defect Fig 2310 Rhomboid flap. Fig 2309by primary suture or a skin graft. secondary defect may be closed The flap. Transposition

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Fig 2311 V-Y advancement flap.

Others include rhomboid (Figure 2310), hatchet or V-Y advancement flaps (Figure 2311). In most cases, the donor site is closed primarily. Some will result in a defect that requires grafting.

Axial flaps 2312 Axial flaps are based on a known blood supply, usually by a single, large and constant vessel. These flaps can be used locally on a pedicle or at distant sites using free tissue transfer techniques with microvascular anastomses (Figure 2312).

537 Peninsular axial pattern flap Peninsular axial pattern Free flap Island axial pattern flap Island axial pattern Fig 2312 Free flaps. Axial and

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Tropical Diseases

Introduction

2401 Provision of medical care in the tropics presents a number of challenges. Many diseases are unique to specific geographical regions; other, more ubiquitous diseases may display a broader clinical spectrum in the tropics. Lack of infrastructure and medical sophistication may exacerbate epidemics (e.g., water borne illness, AIDS). Inadequate immunisation programs can result in development of tetanus in trivial wounds (0825). RTAs often provide a major part of the surgical workload. Clinical manifestations of disease are distorted by multiple disease processes that are at play in the indigenous population. Surgical methods sometimes require modification in the tropics. Humidity and ambient temperature, for example are important considerations when treating burns and during postoperative care. Clinicians must obtain information concerning endemic diseases, medical facilities and circumstances that may influence the care they provide. In general: • Air conditioning helps reduce post-operative complications. • Elective surgery should be avoided in severe hot weather. • Post-operative heatstroke/hyperpyrexia can occur rapidly and be fatal. 539

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• Dehydration must be corrected, even before trivial surgery. • Maintain scrupulous fluid balance charts and allow for large volumes of loss from sweating and insensible loss. • Over-sweating is worsened by bulky dressings; use minimal wound coverage. • Tropical diseases are not confined to the tropics! Service personnel can develop symptoms after returning home.

Fever

2402 Fever constitutes a diagnostic challenge in the tropics. Significant causes are shown in Table 2401. There are four important aetiologies:

Common • Malaria. • Invasive diarrhoeal infections. • Influenza and other respiratory infections.

Less common • Leptospirosis. • Typhoid fever. • Pyogenic bacterial infections. • Rickettsial infections (to include typhus). • Trypanosomiasis. • Acute schistosomiasis. • Acute retroviral syndrome (HIV). • Viral haemorrhagic fevers. • Viral encephalitis.

Table 2401: Potential causes of pyrexia in military populations in the tropics. 540 Chapter_24.qxd 28/09/2004 15:57 Page 541 24: Tropical Diseases 1. Malaria Pathophysiology 2403 Malaria is caused by the plasmodium protozoa. • Sporozoites are transmitted to humans by female anopheline mosquitoes. • Once injected through the skin, they invade hepatocytes to mature as tissue schizonts. Subsequently, these rupture to release merozoites into to the bloodstream where they invade and multiply in RBCs causing haemolysis and the further release of merozoites. These continue the cycle of RBC invasion and haemolysis. • Concomitant with this process is the release of tumor necrosis factor and other cytokines which cause fever and systemic symptoms. • There are four species of malaria that infect humans. P. falciparum is the most malignant and has the highest complication rate.

Clinical features 2404 Malarial may mimic many other conditions. Features include: • Rigors, high fever (up to 41°C), and marked sweating. • Fatigue, headache, dizziness, myalgia, arthralgia, backache, and dry cough. • Typical gastrointestinal symptoms are anorexia, nausea, diarrhoea, vomiting, and cramping abdominal pain. • Textbook malaria fever patterns show periodicity of 48-72 hrs between attacks. In practice, these fever patterns are variable and not usually useful in diagnosis. 541 Chapter_24.qxd 28/09/2004 15:57 Page 542 24: Tropical Diseases

Diagnosis is made by microscopy of thick and thin peripheral blood smears. Because of periodicity of parasitaemia, multiple examinations may be required to exclude the diagnosis. A dipstick antigen-capture assay is available for field diagnosis of P. falciparum and P.vivax malaria (sensitivity and specificity 75 - 95 %).

Complications of P. falciparum malaria: 2405 These include: • Cerebral malaria. • Hyperpyrexia. • Haemolytic anaemia. • Non-cardiogenic pulmonary oedema. • Acute renal failure. • Jaundice without liver failure. • Hypoglycaemia. • Adrenal insufficiency-like syndrome. • Cardiac dysrhythmias. • Gastrointestinal syndromes. • Fluid and electrolyte imbalance. • Concurrent bacterial pneumonia.

Prophylaxis 2406 Drugs useful in prophylaxis of malaria are shown in Table 2402: Prophylaxis should be started one week before travel (preferably 2-3 weeks in the case of mefloquine; Malarone™ 2 days) and should be continued for 4 weeks after leaving (Malarone 1 week). Due to emergence of drug resistant falciparum strains, both prophylaxis and treatment regimens 542 have become complicated. Appropriate prophylaxis Chapter_24.qxd 28/09/2004 15:57 Page 543 24: Tropical Diseases

• Chloroquine 300mg once weekly. • Proguanil hydrochloride 200mg once daily. • Mefloquine 250mg once weekly. • Doxycycline 100mg once daily. • Atovaquone/proguanil (Malarone™) 1 tablet daily.

Table 2402 Drugs useful in malaria prophylaxis (choice of regime depends on local risk and resistance). May be required singularly or in combination.

requires local knowledge of the species prevalence and resistance patterns. Since prophylaxis is never 100% effective, it must be included with other control measures, such as use of window screens, mosquito netting impregnated with permethrin, vector population control, frequently applied insect repellant and protective clothing. Long sleeves and trousers after dark should be a Standard Operating Procedure!

Treatment 2407 The following are examples of common treatment regimens. You must obtain expert advice early in all casualties.

1. Treatment of P. vivax, P. ovale and P. malariae malaria Oral treatment: 600mg chloroquine base, then 300mg chloroquine base at 6-8 hours, then 300mg chloroquine base daily for 2 days. Chloroquine is adequate for P. malariae, but in the case of P. vivax, and P. ovale, a radical cure to destroy liver parasites is required. This is achieved by with primaquine (15mg daily for 14-21 days given after chloroquine).

2. Treatment of P. falciparum malaria In most parts of the world P.falciparum is 543 Chapter_24.qxd 28/09/2004 15:57 Page 544 24: Tropical Diseases

resistant to chloroquine, which should not now be given for treatment. Where the casualty can swallow and retain tablets and there are no serious manifestations (e.g., impaired consciousness), in adults give oral: • Quinine (salt) 600mg three times daily for 7 days and (if quinine resistance known or suspected): Fansidar (3 tablet single dose) or, Doxycycline 200mg daily for 7 days. Alternatives to quinine: • Mefloquine (20-25mg/kg oral single dose or preferably 2-3 divided doses over 24 hours) or, • Malarone (4 tablets once daily for 3 days). Parenteral regimen: In the ill casualty or those unable to swallow, give quinine dihydrochloride, 20mg/kg (salt) in 500 ml of 5% glucose solution i.v. slowly over 4 hours. Thereafter, administer 10mg/kg (salt) three times daily until oral therapy is possible (maximum dose: 1.4g/day).

2. Enteric fever Pathophysiology 2408 This is caused by a range of different organisms, the commonest of which is Salmonella typhi. • Infection occurs after ingestion of contaminated food or water. • There is an incubation period of 5-14 days during which time the intracellular Salmonella pathogens breach the mucosal barrier and 544 replicate in the reticuloendothelial tissues Chapter_24.qxd 28/09/2004 15:57 Page 545 24: Tropical Diseases

of Peyer's patches, mesenteric lymph nodes and the spleen. • Infected tissues become inflamed and ulcerate, resulting in bacteraemic spread of infection. Diagnosis is made by blood cultures. These remain positive for up to three weeks in those who have not received antibiotic therapy. Where this fails to identify the organism, bone marrow cultures are sometimes positive. Serological tests are of little value in the diagnosis of enteric fevers.

Clinical features 2409 Typhoid fever is a systemic illness characterized by: • Malaise, sustained fever and bacteraemia (2-4 weeks). • Rose spots: 2-4 mm maculopapules occurring predominantly on the anterior chest and abdomen (pink; blanch under pressure). • Bradycardia. • Abdominal pain, tenderness and distention. Splenomegaly. • Haemorrhage and perforation. There may be sudden hypotension and tachycardia, with or with out passage of blood per rectum. Small bowel perforation can be difficult to detect in the presence of an already tender and distended abdomen. Look for free fluid in the abdomen or air under the diaphragm on AXR. • Mental confusion. • Hypovolaemic and/or septic shock. • Bacteraemic spread may cause osteomyelitis, septic arthritis, mycotic aneurysm and meningitis. • Relapse occurs in 10-20% of those treated with antibiotics (1-6 weeks after completion of 545 Chapter_24.qxd 28/09/2004 15:57 Page 546 24: Tropical Diseases

therapy). This is probably due to sequestration of intracellular organisms. • Death and severe complications typically occur during the third week of illness.

Treatment: 2410 Measures include: • Oral ciprofloxacin 500 mg twice daily for 10 days, or ceftriaxone 2gm i.v. daily for 14 days. If shock or mental confusion are present, give dexamethasone 3mg/kg i.v. just prior to initiating antibiotic therapy followed by 1 mg/kg i.v. every 6 hours for 8 doses. • Haemorrhage may necessitate blood transfusion. • Surgery is indicated for intestinal perforation. Drug resistance is now widespread and every attempt should be made to confirm the diagnosis by bacterial culture and sensitivity testing.

3. Pyogenic infections Pyomyositis 2411 A soft tissue infection, common in the tropics, which is characterized by pyogenic infection of muscles. Pyomyositis is rare in temperate climates. The resultant woody induration is sometimes misdiagnosed as a malignant mass. Infection is usually confined to muscle, but can occasionally cause septicaemia with metastatic spread to other organs. Staphylococcus aureus is the pathogen in 90% of cases. • Aspirate purulent material for Gram-stain and culture prior to starting therapy. • Treatment is excision of necrotic muscle, drainage of purulent material and antibiotics (0822). 546 Chapter_24.qxd 28/09/2004 15:57 Page 547 24: Tropical Diseases

Toxic shock syndrome 2412 Super-antigen phenomena result from specific toxin production in some Staphylococcus aureus and Lancefield Group A streptococcal infections (Streptococcus pyogenes). Typically, the casualty is more toxic than the infection appears to warrant. There is rapid progression to shock, acute respiratory distress syndrome and renal failure. Unless the infectious source of toxin is eliminated (surgery, antibiotics), deterioration and death is likely. Staphylococcal infections in toxic shock syndrome tend to remain localized. By comparison, streptococcal infections are highly invasive with bacteraemia occurring in the majority of cases. Mortality rates have been reported as high as 80%. • Treatment is surgical drainage and wound excision. Administer high dose penicillin 1.2g i.v./i.m. 4 hourly +/- clindamycin 600 mg i.v. four times daily (clindamycin inhibits toxin production).

4. Schistosomiasis Pathophysiology 2413 Schistosomiasis is a visceral, trematodal parasitic infection caused by one of five schistosomal species that infect humans. The source of infection is fresh water containing snails that allow for the development of the infective cercariae. Innoculation occurs through exposed skin, usually of the lower limb.

Clinical features Illness may be acute or chronic:

2414 Acute: A previously unexposed individual may develop an acute febrile illness (Katayama fever) 4-6 weeks after transmission; this coincides with onset of egg production by maturing schistosomes. The usual cause is Schistosoma japonicum, less commonly 547 Chapter_24.qxd 28/09/2004 15:57 Page 548 24: Tropical Diseases

Schistosoma mansoni. Commonest early symptoms are: • Dysentery (S.mansoni, S. japonicum). • Haematuria (S. haematobium). Later clinical consequences include: • Abdominal pain, weight loss, headache, malaise, chills, fever, myalgia, diarrhoea, dysentery, dry cough, hepatomegaly and eosinophilia. • Acute myelitis has been reported. • Infection may result in death from toxaemia and myocarditis. This is thought to be due to high levels of circulating immune complex. Diagnosis is suggested on history and clinical course. Eosinophilia is common and serological investigations are usually positive.

2415 Chronic: Eggs are produced by adult worms living in veins throughout the body. Ova migrate through blood vessel walls, generating intense inflammatory responses. Clinical features reflect the site of the adult worms (and ova), and are related initially to severe inflammation. Chronic infection results in tissue damage, scarring and carcinomatous change. Clinical consequences include: • Urological system: S. haemotobium and S. intercalatum cause obstructive uropathy, haematuria and bladder carcinoma. • Liver: hepatosplenomegaly, hepatic granulom and periportal fibrosis, leading to portal hypertension and portocaval shunting. • Lung: granulomatous pulmonary arteritis and cor pulmonale. • Gut: intestinal fibrotic pseudotumors and 548 polyposis. The clinical features depend on Chapter_24.qxd 28/09/2004 15:57 Page 549 24: Tropical Diseases

the pattern of egg deposition and tissue inflammatory reaction. Responsible organisms are S. mansoni, S. japonicum, and S. mekongi. • Others: myelopathy and cerebral schistosomal infection. Diagnosis is made by microscopic observation of eggs in faeces or urine.

Treatment 2416 Praziquantel is effective against all human schistosomes. Give 40 mg/kg in 2 divided doses at 4-6 hour intervals. This may be combined with corticosteroids for the acute febrile syndrome. For S.japonicum, 60mg/kg is required in 3 divided doses.

Diarrhoea

2417 Diarrhoeal diseases are a significant cause of morbidity (and for infants, mortality) in the tropics. Common protozoan, bacterial, and viral pathogens are listed in Table 2403. Epidemics frequently occur in the field. Spread of infections can be prevented by: • Avoidance of suspect food and water sources. • Isolation of infected subjects. • Maintenance of adequate toilet facilities. • Scrupulous and frequent hand washing.

Amoebic dysentery Pathophysiology 2418 Although Entamoeba histolytica occurs world wide, it causes infection more frequently in the tropics. On sigmoidoscopy, single or multiple ulcers indicative of invasive disease, can be seen in the rectum or lower colon. Diagnosis:

• Identification of motile trophozoites in the stools, 549 Chapter_24.qxd 28/09/2004 15:57 Page 550 24: Tropical Diseases

• Vibrio cholera, V. parahaemolyticus. • Escherichia coli (toxigenic and entero-invasive). • Protozoa: (Entomoeba histolytica, Balantidium coli Cryptosporidium species). • Giardia lamblia. • Viruses (noroviruses, rotaviruses). • Shigella species (sonnei, flexneri, boydii, dysenter). • Bacterial agents of food poisoning (Clostridium, Bacillus cereus, Staphylococcus aureus). • Salmonella typhi, S. enteritidis, S perfrigens.

• Campylobacter jejuni.

• Schistosomiasis.

Table 2403: Infectious causes of diarrhoea.

scrapings of the exudates or biopsy of the ulcer margins (presence of phagocytized RBCs confirms pathogenicity). NB: the presence of cysts is suggestive of infection but does not confirm active disease. • Serologic tests may be helpful in confirming the presence of extra-intestinal invasive disease. • Differential diagnosis includes: bacillary dysentery (Shigella and entero-invasive E. coli), schistosomiasis, ulcerative colitis, Crohn's disease and carcinoma of the colon or rectum.

Clinical features 2419 Presentation is usually with diarrhoea. Amoebic dysentery typically presents as a subacute illness, in contrast to the sudden onset of severe illness with bacillary dysentery. Complications of amoebiasis include: • Perforation and peritonitis usually respond to conservative management with metronidazole. . • Amoeboma granulomas may cause masses, usually in the caecum, which can result 550 in intussusception. Chapter_24.qxd 28/09/2004 15:57 Page 551 24: Tropical Diseases

Nematodes • Strongyloides stercoralis, S.fülleborni. • Ascaris lumbricoides. • Visceral larva migrans - Ascaris suum. • Trichinella spiralis, T.nativa, T.pseudospiralis, T.nelsoni, T.britovi. • Anisakaisis anisakis, A.pseudoterranova. • Capillaria philippinensis. • Angiostrongylus parastrongylus, A. cantonesis.

Trematodes • Schistosoma mansoni, A. haematobium, S japonicum. • Fasciola hepatica, F.gigantica. • Fasciolopsis buski. • Clonorchis sinensis. • Opisthorcus felineus, O viverrini.

Cestodes • Echinococcus granulosus.

Protozoa • Isospora belli. • Dientamoeba fragilis.

Table 2404: Tropical causes of abdominal pain-associated with eosinophilia.

• Haemorrhage invasive disease with erosion of a bowel vessel may result in massive bleeding. • Hepatic amoebic abscess will usually respond to treatment with metronidazole; occasionally they require needle aspiration.

Treatment 2420 Metronidazole 800 mg orally three times daily for 5 days (or tinidazole 2g daily for 2-3 days). Followed by a 10 course of diloxanide furoate, 500mg three times daily.

551

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• Typhoid fever -Salmonella typhi. • Amoebiasis - Entamoeba histolytica.

• Salmonella typhumirium, S enteritidis. • Enterohaemorrhagic and enteroinvasive Eschericha coli. • Halophilic Vibrio infections - V. parahaemolyticus, V.alginolyticus, Vvulnificus. • Campylobacter jejuni. • Shigella dysenteriae, S boydii, S. flexneri, S.sonnei.

Table 2405: Tropical causes of abdominal pain without eosinophilia.

Abdominal Pain

2421 Medical causes of abdominal pain in the tropics are listed in Tables 2404 and 2405. These are considered with and without the presence of eosinophilia. When confronted with an acute abdomen suggestive of appendicitis, consider the conditions listed in these tables and do not forget acute sickle cell crisis.

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Field Anaesthesia and Intensive Care

Introduction

2501 Anaesthesia has two main aims: Anaesthesia in forward areas is 1. To control physiology e.g., pain, BP, not for the muscle activity and intracranial pressure. inexperienced. It is challenging and 2. To provide suitable conditions for surgery needs to be e.g., sleep, amnesia and muscle relaxation. approached with a cool head and common sense. 2502 The type of anaesthesia that the military A cavalier attitude anaesthetist can provide will depend on: or cutting corners will lead to a drop • Their training and skill level. in clinical standards. • Available resources, including anaesthetic equipment, drugs, fluids, syringes, needles. This may appear trivial but, in a field situation, even simple equipment may be in short supply. • Supporting personnel to provide care for the casualty before, during and after surgery. • Tactical situation. • Mobility of the surgical facility.

Environment 2503 Safe anaesthesia requires a safe environment. This means: • Adequate shelter, clean water and lighting. Spacious, pre-fabricated units e.g., a Modular Transportable Surgical Facility (MTSF) or buildings are preferable.

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Cleanliness and casualties and sensitive equipment. A high asepsis are problems in forward temperature predisposes to adverse outcome units where clean following head injury, whilst a low temperature water is in short leads to hypothermia, especially in unconscious supply. Take care to casualties with disordered thermoregulation and minimise the risk of infection when limited physiological reserves. Tented structures performing central are usually more difficult to thermoregulate and venous or arterial keep clean. cannulation. Once transferred, • A reliable power supply with at least one it may be safer back up system and a large number of electrical to change all the sockets in the operating theatre and intensive casualty's lines. care unit (ITU). • Correct maintenance of anaesthetic equipment, generators and climate control systems.

Roles 2504 You may find yourself in one of the following situations: • At a fully equipped Role 3 Field Hospital. Here it may be possible to provide a standard of anaesthesia and post-operative care similar to that in the UK. Personnel working within a host nation hospital may encounter marked

Wherever you differences in staff, medicines and equipment. are, the aim must • As part of a Field Surgical Team (FST) forward be to treat the casualty as safely at Role 2. Here, compromises in medical care and humanely as will be necessary. possible with the constraints of • A member of an Incident Response Team (IRT), the situation. often working alone in difficult and dangerous circumstances at the scene of an incident. Here, the emphasis will be on speed of action and rapid casualty transfer.

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Introduction 2505 Military casualties are usually fit young soldiers from a medically screened population. Be prepared to treat local civilians, refugees, children, pregnant women and the elderly; all of whom may have pre-existing medical conditions. Complicating factors may include: delays in treatment, sepsis, dehydration, malnutrition and emotional or psychiatric problems. Casualties will have received variable pain relief and resuscitation.

2506 Injuries may be battle or non-battle in origin. Often, such casualties require several operations to produce healing e.g., contaminated wounds and burns; anaesthetic techniques need to be adapted accordingly.

Preoperative assessment 2507 A careful preoperative assessment is as important in the field as in a peacetime, civilian hospital: • Follow the principles outlined in Battlefield Advanced Trauma Life Support (BATLS) to ensure that no potentially serious injuries are been missed. • Ask about past medical history, medications, allergies and previous anaesthetics. • Look for any Medic Alert tags. A number of anaesthetic concerns are emphasised:

Airway 2508 Considerations include: • Because of the risks of vomiting and aspiration, all trauma and emergency casualties should be 555

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Nerve Agent Pre- assumed to have a full stomach and usually treatment System (NAPS) tablets - need endotracheal intubation for anaesthesia Pyridostigime, have and surgery. The time of the casualty's last no clinically meal is a poor guide to gastric contents. important effect on Trauma and opiate administration both delay the action of muscle relaxants at the gastric emptying. The risk of aspiration can neuromuscular be reduced by: junction or their reversal with • Emptying the stomach with a nasogatric neostigmine. tube and suction in non-urgent cases. • Being prepared to perform immediate suction and head down tilt. • Applying cricoid pressure during rapid sequence induction (3009). • Premedication with an anti-emetic e.g., metoclopramide 10mg i.v. and an antacid, H2 blocker or proton pump inhibitor. • During endotracheal intubation, casualties in C-spine immobilisation should have their collar opened or removed and substituted by manual in-line stabilisation. • Casualties with penetrating neck injuries involving the larynx and trachea will need a surgical airway rather than intubation. Consider cricothyroidotomy (3005) for injuries above the cricothyroid membrane and tracheostomy (3007) for those below.

Breathing 2509 Make sure the casualty does not have a pneumothorax prior to intermittent positive pressure ventilation (IPPV). IPPV can convert a simple pneumothorax to a tension pneumothorax. If in doubt, insert unilateral or bilateral chest drains before starting IPPV.

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Circulation 2510 With the exception of the casualty suffering from non-compressible haemorrhage who requires immediate surgery, fluid resuscitation should be underway before induction of anaesthesia. Personnel on military operations are likely to be dehydrated and exhausted prior to injury, especially in hot climates. This will compound the degree of shock resulting from haemorrhage. For example, in Class III shock, give 1-2L of warm crystalloid (Hartmann's, 0.9% Saline) or colloid (Haemaccel, Gelofusin), at induction. Unless adequately resuscitated at induction, decompensation can result in profound hypotension.

Analgesia and premedication 2511 Find out the dose and timing of opiate analgesia given during the evacuation chain. This may still be effective and avoid the need for premedication. Remember, shock and cold can delay absorption of i.m. morphine (0706). This caution should not prevent a casualty from receiving adequate analgesia, titrated to effect, as soon as possible (Figure 0701). Equally, opiates should not be withheld on the grounds that the casualty is scheduled to receive an anaesthetic. Where time permits, opiate or benzodiazepine premedication will reduce anxiety.

Anaesthetic Technique

Introduction 2512 There are many anaesthetic techniques and the following is intended only to be a guide. The most commonly used method in British military practice is the balanced technique with intermittent positive pressure ventilation using the Tri-Service Anaesthetic Apparatus. Balanced anaesthesia comprises sleep, 557

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analgesia and muscle relaxation. If you have limited equipment or are inexperienced, Total Intravenous Anaesthesia (TIVA) using Ketamine, is the safest option (2521).

Methods for Overview of balanced anaesthesia continuous infusion Sleep include a syringe pump or, adding the 2513 Casualties are put to sleep using i.v. or drug to a bag of intravenous fluid inhaled anaesthetic agents. Sleep is then maintained (if drug and fluid using intermittent i.v. injections, a continuous infusion are compatible). or by inhalation through an anaesthetic breathing system. Intravenous drugs for this purpose include: thiopentone, propofol, midazolam and ketamine. Isoflurane is the preferred inhalational agent. Anaesthetic drugs can cause hypotension due Oxygen and to vasodilation and cardiac depression. A degree anaesthetic agents may be in short of muscle relaxation and analgesia is also produced. supply. Consider using local or Analgesia regional anaesthesia and ketamine. 2514 This is usually achieved using i.v. or i.m. opiates or local anaesthesia. Commonly used opiates include: morphine (0706), fentanyl and alfentanil. Ketamine has both anaesthetic and analgesic actions (0714). Lignocaine or bupivacaine may be infiltrated locally or used for regional plexus blockade (0728). Plexus blockade will also produce a degree of muscle relaxation.

Muscle relaxation 2515 This assists anaesthetic access to the airway for endotracheal intubation and surgical access during major procedures. Commonly used neuromuscular blocking agents include: suxamethonium, vecuronium or pancuronium. These produce temporary muscle paralysis, but do not provide sleep or analgesia.

558

Ketamine: see 0714 Chapter_25.qxd 28/09/2004 15:58 Page 559 25: Field Anaesthesia and Intensive Care A suggested balanced anaesthetic technique for emergency cases Induction of anaesthesia 2516 Steps include: • Shocked or dehydrated casualties should be resuscitated prior to anaesthesia. The timing of this to coincide with the start time of surgery is critical, in terms of rebound hypertension causing an increase in bleeding. Use appropriate combinations of crystalloid, colloid and blood. This should be continued during induction. • Preoxygenate as soon as the casualty has been transferred to theatre. The time required for effective preoxygenation will depend on the flow of oxygen available and the breathing system in use; two minutes preoxygenation at 15l/min is usually adequate. • Induction of anaesthesia takes place on the operating table using a rapid sequence technique with application of cricoid pressure until the position of the endotracheal tube has been checked and the cuff inflated. A working sucker should be immediately available in case of regurgitation. • Give i.v. morphine 5-10mg for analgesia if required. Alternatively, use a short-acting opioid such as fentanyl (1-1.5mcg/kg) or alfentanil 10-15mcg/kg. These two drugs have the advantage of reducing the hypertensive response to intubation. • The choice of induction agent depends on availability, familiarity and the clinical scenario. Ketamine and etomidate produce less cardiovascular depression than thiopentone and propofol, especially in the shocked casualty. Adult doses by slow i.v. injection are: 559

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• Ketamine 1-2mg/kg • Etomidate 0.2-0.6mg/kg • Thiopentone 3-5mg/kg • Propofol 1.5-2.5mg/kg (less in those >55years) NB: reduce the above doses in shocked casualties. • Suxamethonium chloride, 1mg/kg is a depolarising muscle relaxant. It acts within one minute and usually lasts less than 5 minutes; it facilitates rapid tracheal intubation. Depolarisation usually causes the casualty to twitch. Wait for this to stop prior to passing the endotracheal tube. • Once intubated, the endotracheal tube is connected to the anaesthetic breathing system and the casualty is ventilated, initially by hand with the self-inflating bag and then, with the bag removed, by the ventilator. Make sure the endotracheal tube is secure prior to proceeding.

Maintenance 2517 Steps include: • The casualty is ventilated with air supplementary oxygen and isoflurane 1-2%, depending on clinical condition and what other drugs have been administered. Nitrous oxide, with its analgesic and anaesthetic actions, is widely used in UK civilian practice as a carrier gas. Logistical reasons mean it is not usually available in the field. Anaesthetists used to giving nitrous oxide will have to modify their technique, substituting larger doses of opiate or isoflurane instead. ·• Once the suxamethonium has worn off, paralysis can be maintained with vecuronium. The initial 560 adult dose is 80-100mcg/kg i.v., followed by

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20-30mcg/kg every 20-30 minutes according to response. • Further intermittent doses of i.v. opiates, In adequately ventilated and morphine (1-2mg), fentanyl (25-50mcg) and previously fit alfentanil (250-500mcg) are used to provide casualties, the analgesic component of anaesthesia. acceptable levels Peroperative opiate requirements vary widely of arterial oxygen saturation can be depending on the type of surgery and maintained with previous analgesia. no oxygen supplementation. • During the maintenance phase of anaesthesia, oxygen flow can be reduced to 1litre/minute if stocks are limited. Monitor the oxygen saturation, aiming for 94% or greater.

Reversal 2518 At the end of the procedure: • Isoflurane is turned off, the flow of oxygen increased and residual paralysis reversed with neostigmine 2.5mg and atropine 0.6mg i.v. over 1 minute or, neostigmine 2.5mg and glycopyrolate 0.5mg i.v. • Casualties should be extubated awake, on their side and with head down tilt. • Postoperative analgesia can be achieved with continuous i.v. infusion of morphine or by intermittent i.m. injections, according to the battlefield analgesia algorithm (Figure 0701). Patient controlled analgesia (PCA) may be available at Role 3. • Critically ill casualties are best transferred ventilated from the operating theatre to the intensive care unit (ITU) for further resuscitation and warming prior to extubation. If an ITU bed is unavailable, continuing ventilating the casualty and transfer them as soon as practicable to a rear hospital. Repatriation by a specialist aeromedical transfer team may be appropriate. 561

Aeromedical Evacuation: see 2908 Post-operative morphine: see 0707 Chapter_25.qxd 28/09/2004 15:58 Page 562 25: Field Anaesthesia and Intensive Care Balanced anaesthesia for non-emergency cases Waiting times 2519 Semi-elective cases such as delayed for semi-elective cases can be primary suture, change of burn dressings or drainage unpredictable. of abscesses, can be appropriately starved before Avoid dehydration surgery. Because there is less risk of vomiting and by giving i.v. fluids. aspiration, they can be anaesthetised using a spontaneously breathing technique. This involves an oropharangeal or nasopharyngeal airway and mask, or insertion of a laryngeal mask airway. Oxygen supplementation should be provided throughout the procedure.

Total intravenous anaesthesia (TIVA) 2520 TIVA is relatively simple and avoids pollution by anaesthetic vapours. Three proven techniques are described. 1. Ketamine as the sole anaesthetic agent 2521 Ketamine has features which make it suitable for use in trauma e.g., the extrication of a casualty from the scene of a RTA where access is difficult. It is the drug of choice where an anaesthetic is to be administered by the inexperienced.: • The usual induction doses are 2mg/kg i.v. or 10mg/kg i.m. Smaller doses are used to provide analgesia in a conscious casualty (0714). • Anaesthesia is induced 45 seconds after i.v. administration and lasts 5-15 minutes, with a longer period of amnesia. • Following i.m. injection, anaesthesia is induced after 5-10 minutes and the effect is significantly longer and more variable. • A technique suitable for longer procedures using ketamine alone involves an i.v. induction dose, followed immediately by an i.m. dose (200-500mg in the adult) with i.v. supplements of 562

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100mg, as required to suppress reflex responses to stimulation. • Hallucinations are reduced by recovering the casualty in a quiet and darkened area.

2. Ketamine and midazolam 2522 A TIVA technique combining ketamine and midazolam has been developed for use in the field. This has been shown to produce satisfactory anaesthesia with minimal hallucinations, even when casualties are not nursed in a quiet, dark area. Blood pressure and pulse rate tend to be maintained. • After opiate premedication, induction is achieved with midazolam 0.07mg/kg and ketamine 1mg/kg. Anaesthesia is maintained with an infusion of a mixture of the two drugs. The mixture is obtained by combining midazolam 5mg, ketamine 200mg and normal saline to a total volume of 50mls. The rate of administration is calculated as: Casualty's body weight in kg = mls/hr 2 • This gives rates of midazolam of 50mcg/kg/hr and ketamine 2mg/kg/hr. The mixture can be made up in advance with a shelf life of 72 hours. • Suxamethonium and rapid sequence induction are employed where indicated. Paralysis can be maintained by adding vecuronium 12mg to the infusion mixture or by administering the drug as described in 2517.

3. Propofol and alfentanil 2523 Propofol and alfentanil are commonly used in civilian practice to provide TIVA. Both drugs are short-acting, resulting in a rapid, clear-headed recovery, with a low incidence of nausea and 563 Chapter_25.qxd 28/09/2004 15:58 Page 564 25: Field Anaesthesia and Intensive Care

delirium, allowing safer onward casualty transfer. These attributes allow rapid movement from the theatre and recovery area to a lower dependency ward or, early inter-hospital transfer, if required. The cardiovascular depressant effects of propofol make this drug unsuitable in casualties who are not fully resuscitated. • After an induction dose of propofol of 1.5-2.5mg/kg (less in those >55years) and alfentanil 10-15mcg/kg and muscle relaxation, anaesthesia is maintained in the ventilated casualty with a mixture of 1.5mg of alfentanil added to 500mg of propofol in a 50ml syringe. The infusion rate is initially 10mg/kg/hr for the first 10 minutes, then altered according to clinical signs - pulse rate, BP, respiration, pupil response and absence of sweating, aiming for a final infusion rate of 5mg/kg/hr.

Regional Anaesthesia Spinal anaesthesia 2524 Spinal block is contraindicated in the shocked casualty, due to the potentially catastrophic loss of sympathetic tone and consequent profound hypotension. Spinal anaesthesia in the field carries a significant risk of infection. It may be a practical choice, for those medical staff unable to administer general anaesthesia, for surgery on the lower abdomen and legs. Epidural 2525 The administration of local anaesthetic drugs via the epidural route, although more easily titrated than the spinal route, has similar disadvantages. Its use for postoperative analgesia may be considered in rear hospitals, where asepsis can be more readily achieved.

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Local block 2526. Wound infiltration with local anaesthetic and nerve blocks, can be usefully employed as an adjunct to general anaesthesia and analgesia (0728). Nerve blocks alone are unlikely to be sufficient for surgery, as wounds rarely respect anatomical boundaries.

Equipment General 2527 Anaesthetic and monitoring equipment used in forward, mobile areas, should be compact, lightweight and robust, yet sophisticated enough to comply with peacetime standards. They should be of a type familiar to military anaesthetists through peacetime employment. Electrical equipment should have battery back up, especially items used in the transfer of casualties, such as ventilators and monitors. Avoid items which require frequent resupply for example, a ventilator driven only by compressed gas is inappropriate in forward units with a limited number oxygen cylinders and no guaranteed resupply.

Oxygen 2528 A critically ill casualty may require 10 litres/min of oxygen (14400 litres/day). A common approach to supplying oxygen in the field is the use of portable, oxygen concentrators, with cylinder back up for emergencies. Five litres/minute of 92% oxygen is the maximum output of the commonly used, floor standing oxygen concentrator.

Refrigeration 2529. Refrigeration is another potential problem. "Thermopols" are used to store blood and temperature sensitive drugs. Their performance should be regularly monitored. The "cold chain", from supplier to user, must be reliable. Where 565

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Fig 2501 The Tri-Service Anaesthetic Apparatus (TSAA). possible, drugs that are not temperature sensitive should be used, as refrigeration space is likely to be limited.

Monitoring equipment 2530 Equipment used in the field includes the Propaq series and the Datex-Engstrom Compact and Datex-Engstrom Lite.

Anaesthetic apparatus and ventilator

The OMV Tri-Service 2531 The Tri-Service Anaesthetic Apparatus (TSAA) Vaporiser is not fully continues to be the main anaesthetic system used by temperature British Forces in the field. It was developed for the compensated. Consequently, the administration of halothane and trilene. It is now output will fall with routinely used with isoflurane alone. It consists of rising temperature as a Laerdal Resusci bag (self-inflating), a one-way a result of agent patient valve, an Oxford Miniature Vaporiser (OMV), vaporisation. This should not be a a Sanders Oxygen 'T' and a length of reservoir problem at ambient tubing. In the configuration shown in Figure 2501, temperatures the TSAA is used for spontaneous ventilation or suitable for surgery. manual positive pressure ventilation with the self-inflating bag.

2532 The TSAA can be used in conjunction with the CompPAC ventilator (PneuPAC, Luton UK) 566 (Figure 2502). This is a flow generating, time cycled Chapter_25.qxd 28/09/2004 15:58 Page 567 25: Field Anaesthesia and Intensive Care

2

1

1: To front connection 2 Compressed oxygen at 2.5 - 6.0 Bar o driving the compPAC 2: To rear connection Compressor driven (max 4L/min flow) with oxygen supplementation (oxygen flow selector set to 2-15 l/ min at 1 Bar)

Fig 2502 Ventilation using the ComPAC ventilator in either 1) oxygen-driven or 2) compressor driven mode.

ventilator. As the unit incorporates an air compressor, it can be driven electrically or by compressed gas. The electricity source can be from an internal battery (Lithium or rechargeable NiCad), an external AC source, via a transformer, or a 24-28v AC supply. When driven by compressed oxygen, the output can be set at either 45 or 100%. When driven electrically, ambient air is drawn in through a NATO standard NBC filter and compressed. Supplementary oxygen can be added either at the back of the unit at 0.5-4 litres per minute, or at the Sanders 'T' when in use with the TSAA. The CompPAC is used with the OMV Tri-Service vaporiser in push over mode, driving the oxygen or oxygen-enriched air through the vaporiser and into the casualty via the one-way patient valve. 567 Chapter_25.qxd 28/09/2004 15:58 Page 568 25: Field Anaesthesia and Intensive Care Intensive Care in the Field

Introduction 2533 Intensive Care (IC) is the provision of support to two or more vital organ systems or a high level of respiratory support in isolation, to a critically ill casualty.

2534 High Dependency Care (HDC) is the support of one vital organ system, excluding respiratory support.

2535 IC/HDC in an operational environment has become necessary due to improved early resuscitation, reduced time to surgery in battlefield casualties and as a vital adjunct to damage control surgery. Ideally, such support should be available as far forward as the Role 2 Field Surgical Team (Role 2+). In most situations, care will be required for a maximum of 48 hours.

Indications for IC support 2536 These include: 1. To stabilise the ill casualty prior to transfer. 2. To manage casualties in acute organ failure or, at high risk of developing organ failure, who are likely to benefit from continuous high level monitoring and support. 3. Where the situation and environment prohibit movement of the severely ill casualty. Examples are: poor weather preventing helicopter transfer, movement by road is too prolonged and when evacuation facilities are overwhelmed.

Warning signs of a casualty requiring IC support 2537 These include: 568

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• Altered conscious level post resuscitation If you think the or persisting beyond expected recovery time casualty may need from anaesthesia. ITU support then they probably do. • Respiratory failure or distress (PaO2 < 10kPa If in doubt, discuss on >40% oxygen, PaCO2 > 6.5kPa, and RR early with senior <10 or >30 breathes per minute). ITU staff. • Persistent hypotension or tachycardia (>120 beats/minute) despite adequate fluid resuscitation. • Low urine output (<30 mls/hr for >2 hours despite vigorous fluid resuscitation). • The casualty has received a massive blood transfusion (circulating volume replaced in < 24 hours). • Specific injuries e.g., major thoraco-abdominal trauma, severe head injury, burn > 20% BSA, burns complicated by anatomical site or inhalation and combined chemical and conventional injury.

Assets required. 2538 IC in the field is a major drain on manpower and logistic resources. Each casualty requires more space, staff, drugs dressings, equipment and power than other casualties.

Staff 2539 Improvements in ICU care are largely due to the increased ratio of staff to casualties. The following is the minimum requirement: 1. Intensive care-trained medical staff, including a consultant available 24 hours a day. 2. Intensive care-trained nurses at a ratio of one per casualty, 24 hours a day. 3. Other support staff, e.g., physiotherapists. 569 Chapter_25.qxd 28/09/2004 15:58 Page 570 25: Field Anaesthesia and Intensive Care

Environment and logistical support 2540 Requirements are similar to those in the operating theatre (see 2503).

Equipment 2541 This must meet peacetime standards, be sturdy, portable, reliable, easy to repair and flexible in the supplies it requires to function. Packaging should be robust and re-usable. The main items required are: 1. Bed with suitable mattress so as to protect pressure areas and allow optimal positioning of the casualty - sitting up, head up or head down tilt. 2. Ventilator with oxygen supply which is able to function without compressed gas (2532). 3. Suction. 4. Back up oxygen supply with self-inflating bag and non-rebreathing valve in case of ventilator failure. 5. Casualty monitor with ECG, oxygen saturation probe, non-invasive blood pressure, temperature, at least two invasive pressure channels and capnography (e.g., PROPAQ 106EL, DATEX Lite). 6. Six syringe drivers and two volumetric infusion systems per bed, allowing a number of drugs and fluids to be given simultaneously. 7. Defibrillator. 8. Extensive pharmacy including: sedatives, analgesics, inotropes and other cardioactive drugs, antibiotics, bronchodilators, anticoagulants, diuretics, antacid preparations, anticonvulsants, insulin and i.v. fluids. Refrigeration will usually be necessary. 570 Chapter_25.qxd 28/09/2004 15:58 Page 571 25: Field Anaesthesia and Intensive Care

9. Laboratory support including haematology, biochemistry, blood bank, blood gas analysis and microbiology. 10. Radiology. 11. Flexible bronchoscope.

Organ support. Prolonged endotracheal intubation and respiratory support 2542 Indications are listed in Table 2501

• Respiratory failure can become part of any major Over-ventilation of illness or injury. Chest trauma, prolonged life head injuries is now saving surgery, massive blood transfusion and considered harmful - see 1609 sepsis, are some of the common causes encountered in the field. • For efficient positive pressure ventilation, the airway needs to be secured with a correctly positioned endotracheal tube. This will also

decrease the risk of aspiration. In persistent • The casualty will require sedation in order shock despite resuscitation, to tolerate the endotracheal tube and positive consider pressure ventilation. If sedation and analgesia non-haemorrhagic are adequate, they do not usually need causes, especially to be paralysed. Suitable agents include if this follows a therapeutic a combination of midazolam (1-10mg/hr) procedure. or propofol (50-200mg/hr), with alfentanil For example, IPPV (1-5mg/hr) or morphine (1-10mg/hr). Propofol in a casualty with and alfentanil together has the advantage of multiple rib fractures may precipitate a shorter recovery time when sedation is a tension terminated. Ketamine can also be used and may pneumothorax if a be advantageous in the hypotensive casualty. chest drain has not been inserted. • The tidal volume and respiratory rate vary with size, age, and clinical situation. A starting point in a 70kg adult is to set the ventilator to deliver a tidal volume of 700 ml, at a rate of 12-14 breaths per minute. 571

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• Using the arterial blood gas results as a guide, tidal volume and respiratory rate can be adjusted to achieve a PaCO2 of 4.5 - 5.5 kPa. Following a head injury, the target PaCO2 should be 4 - 4.5 kPa.

• The PaO2 is mainly controlled by adjusting the inhaled oxygen concentration to maintain a value greater than 10kPa.

Cardiovascular support 2543 Hypovolaemia is the main cause of shock in both the trauma victim and a casualty who has recently undergone surgery. Further bleeding or third space losses into the abdomen, pelvis or tissue compartments can occur, especially in major abdominal trauma and burns casualties. The following standard of cardiovascular monitoring can be offered in a field ICU: • ECG. • Pulse oximetry. • Core and peripheral temperature gradient. • Urine output - as a measure of end organ perfusion. • Invasive arterial monitoring. • Central venous pressure monitoring. • Pulmonary artery pressure monitoring and cardiac output measurement (not usually available in forward ITUs).

2544 Indications for an arterial line are: • Anticipated haemodynamic instability requiring beat to beat monitoring. • Guidance of inotropic or vasodilator therapy. • Repeated blood sampling, especially for arterial 572 blood gas measurement. Chapter_25.qxd 28/09/2004 15:58 Page 573 25: Field Anaesthesia and Intensive Care

2545 Technique of arterial line insertion The usual site is the radial artery at the wrist. Palpate to check the presence of both the radial and ulnar arteries. After cleaning the skin, insert a 20G cannula without an injection port, at 45 degrees and advance in a cranial direction when you see the flash back. Monitoring of pressure is then through a specific transducer set with a sampling port, which slowly infuses 0.9% Saline to prevent occlusion.

2546 Indications for insertion of a central venous line: 1. Monitoring of central venous pressure as an extra guide to fluid resuscitation. 2. Administration of i.v. drugs, e.g., inotropes and antibiotics.

2547 Technique of central venous line insertion • The commonest site used is the right internal jugular vein. Landmarks used for insertion are just lateral to the carotid pulse at the mid-point of a line drawn between the suprasternal notch and the mastoid process (Figure 2503). The casualty should be positioned supine, slightly head down and with the head turned away from the side of insertion (Figure 2504). Anaesthetise the skin with a wheal of 1% lignocaine. Attach an ECG monitor (NB: if the casualty develops arrhythmias, withdraw slightly). • Using an aseptic Seldinger technique, the needle is inserted at 45 degrees to the skin, directed towards the ipsilateral nipple until venous blood is aspirated. A guide wire is inserted and the needle removed. A dilator is passed over the wire and then removed. The catheter is now inserted over the guide wire. It should pass without resistance. The tip of catheter should be in the superior vena cava just above the right 573 Chapter_25.qxd 28/09/2004 15:58 Page 574 25: Field Anaesthesia and Intensive Care

Internal jugular vein Sternocleido mastoid muscle

Clavicle

Subclavian artery

Subclavian vein First rib

Fig 2503 Land marks for the internal jugular and subclavian veins.

atrium. Estimate the length required from the puncture site prior to insertion. • An alternative is to cannulate the subclavian vein. Identify the junction of the lateral third of the clavicle with its medial two-thirds. Inject a wheal of local anaesthetic just below the bone. Insert the needle horizontally through the skin and underneath the clavicle (Figure 2505). Aim towards the contralateral mid-clavicular point. Aspirate as you advance. • Most catheters have three or four lumens to allow for simultaneous monitoring (Figure 2506)

574 Fig 2504 Casualty position and approach to the internal jugular vein. Chapter_25.qxd 28/09/2004 15:58 Page 575 25: Field Anaesthesia and Intensive Care

A

B

Fig 2505 Cannulating the subclavian vein. A) The skin is punctured at the junction of middle and outer thirds of the clavicle. The needle is advanced under the bone aiming for the contralateral mid-clavicular point. Once blood is aspirated a guide wire is advanced. B) The catheter is passed over the guide wire and fixed in place. and administration of multiple drugs. These should be aspirated and flushed with heparinised 0.9% Saline to check patency and then capped off. The line is sutured in place. A chest radiograph is performed to check correct positioning of the catheter tip in the superior vena cava and to exclude a pneumothorax.

2548 Inotropic drugs These may be required for shocked casualties in whom reversible causes have been excluded; e.g., tension pneumothorax and cardiac tamponade and who fail to respond to resuscitation. Inotropes can be divided into two main groups: inodilators and inoconstrictors. 575 Chapter_25.qxd 28/09/2004 15:58 Page 576 25: Field Anaesthesia and Intensive Care

Manometer

(marked in cm H2O)

10 cm 5 cm 0

Zero mark on manometer level with right atrium

Fig 2506 Measuring central venous pressure using a manometer. Prime the system with saline. The casualty is positioned at 45 degrees. The zero mark on the manometer should be level with the right atrium. Turn the three-way tap to connect the manometer and central line and read off pressure.

• Inodilators cause increased cardiac contractility and vasodilation. This results in a rise in cardiac output but little affect on blood pressure. Unresponsiveness Examples include dopexamine (0.5-2 mg/kg/min) to inotropes should and dobutamine (2.5-20mg/kg/min). prompt further re-assessment to • Inoconstrictors cause increased cardiac ensure a treatable cause has not been contractility and vasoconstriction. The result missed. is a rise in blood pressure above that which one would expect from the increase in cardiac output alone. Commonly used drugs are noradrenaline (0.05-1mg/kg/min) or high dose adrenaline (0.1-2mg/kg/min).

Nutrition 2549 Early nutrition following major illness or injury is beneficial, especially using the enteral route - nasogastric tube or gastrostomy. Total parenteral nutrition is reserved for casualties in whom the enteral route is not possible, or for those with special circumstances. 576 Chapter_25.qxd 28/09/2004 15:58 Page 577 25: Field Anaesthesia and Intensive Care

Renal Support 2550 Haemodialysis or haemofiltration is unlikely be available in forward areas. Renal support is not necessary during the first 48 hours after injury. If acute renal failure does develop during this time, its effects can be controlled by careful fluid balance The best treatment and control of serum potassium and acid-base for renal failure is to avoid it by early, balance by pharmacological means, (e.g., insulin and aggressive dextrose, sodium bicarbonate), until casualty transfer. resuscitation and continued support.

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1. Unable to maintain secure airway • Decreased level of consciousness. • Absent gag reflex. • Severe facial injuries. • Inhalation burns. • Risk of aspiration. • Direct airway injury or oedema.

2. Failure to maintain adequate gas exchange despite supplemental oxygen (PaO2 <10kPa, PaCO2 > 6.5kPa) • Respiratory depression e.g., head injury, morphine overdose. • Spinal cord injury. • Chest wall injury, e.g., flail chest with pulmonary contusion. • Inadequate analgesia ("it hurts to breathe"). • Inhalational or aspiration injury.

3. Severe head injury • Glasgow Coma Score < 10 or decrease of 2 • Signs of raised intracranial pressure • Irregular respiratory pattern

4. Risk of the above occurring during transfer of the casualty

578 Table 2501 Indications for prolonged respiratory support. Chapter_26.qxd 28/09/2004 15:58 Page 579 26: Heat, Cold and Immersion Injury Chapter 26

Heat, Cold and Immersion Injury

1. Heat Illness

2601 Heat illness is an acute syndrome caused Heat illness must be by an excessive rise in core temperature. This occurs excluded as a cause as a result of overloading, or failure of, the of collapse during thermoregulatory system during exposure to heat exercise. A single case may be a stress (heat stroke), exercise (exertional heat injury), warning that other or both. Certain organs, particularly the brain, are personnel are at risk. intolerant of temperature change: an increase to o 43 C will cause death. In hot climates, several days acclimatisation are necessary to allow the sweat glands to begin secreting the large quantities of sweat needed for temperature regulation during strenuous activity. Military personnel are at greater risk in a jungle (continuously hot and wet), as opposed to a desert environment (hot and dry, cold at night). They are particularly vulnerable whilst wearing IPE (0228).

2602 Clinical features • These include: thirst, headache, nausea or Exertional heat injury can result from short vomiting, weakness, fatigue, agitation, duration exercise, staggering and loss of coordination, cramps, typically occurring hyperventilation, disturbed vision, dizziness, within one hour or impaired judgement, confusion, collapse, 5km of the start of a run. seizures, loss of consciousness and death. Sweating eventually ceases and the skin becomes flushed and dry. Prodromal features occur in 20-25% of cases. • Diagnosis is supported by a high (>40°C) core temperature (NB: unless measured at an early 579 Chapter_26.qxd 28/09/2004 15:58 Page 580 26: Heat, Cold and Immersion Injury

stage - this may not reflect the peak Prevent heat illness by: temperature attained). • Adequate water • Prognosis depends on the length of time the and salt intake. body temperature remains elevated. • Acclimatisation. • Physical fitness. 2603 A note on core temperature measurement • Reduced activity. • Appropriate • The rectum (15 cm beyond sphincter) is clothing. the preferred site, especially in suspected • Avoiding alcohol. hypothermia. Alternatively, measure intra-aural (requires care and experience) or oesophageal temperature. • Regularly calibrated electronic thermometers are the most accurate. • Oral and tympanic membrane (infrared) thermometers (as opposed to intra-aural) are unreliable and unsuitable for regular monitoring.

Management

Treatment in the field 2604 The extent of treatment will depend on the circumstances: Treatment of hyperthermia is • Check ABCD (0302). Administer oxygen (0317). rapid cooling: • Strip. • Move casualties to the shade or away from • Soak. radiant heat. Keep them recumbent and stop • Fan. further physical activity. • Fluids. • Undress casualties and cool them by soaking Do not use ice or with tepid water. very cold liquids. • Fan to assist evaporative cooling and continue to cool and fan until fully recovered. • Measure rectal temperature (where possible). • Administer oral fluids and glucose to conscious casualties, otherwise give 1-2 litres of normal saline by intravenous infusion in the first hour. 580

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• Monitor: Be aware of the risk of vomiting during • Pulse. recovery. Place the unconscious • Respiratory rate. casualty in the ¾ prone position. • Consciousness level - AVPU and GCS Because of the (1610, 1614). increased metabolic rate, hyperthermic • Temperature. casualties are often hypoglycaemic. • Transfer casualties to a Role 2 or 3 facility if there is a rectal temperature >40°C, a reduced level consciousness or failure to respond to cooling.

Continued treatment at Roles 2 and 3

2605 This includes: Convulsions generate more heat • Continue cooling and fluid administration. - treat promptly. Perform a more detailed examination. • Monitor rectal temperature, ECG, blood glucose and urine output regularly. • Treat convulsions (1609). A casualty who • Consider transfer to HDU or ITU if response has sustained heat to treatment is poor. illness may be more susceptible to the effects of heat in the HDU/ITU care future. They should 2606 Measures include: be referred to a heat illness specialist for • Continue to cool. assessment. • Consider intubation and ventilation - severely hyperthermic casualties are often hypoxic. • Monitor: Continue to cool until rectal • Rectal temperature. temperature is <38.5°C. Once • Blood gases. stable, monitor for a further 48 hours. • Accurate fluid balance (assessing output via urinary catheter). 581

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• CVP (NB: risk of fluid overload and pulmonary oedema). • Clotting, liver function, creatinine kinase and myoglobin clearance; this helps assessment of the degree of DIC, liver and muscle damage. • Treat oligura with mannitol once fluid volume has been replaced. Aim for 100ml urine output per hour, especially if there is evidence of rhabdomyolysis (look for blood or protein in the urine). • There may be some benefit in treating cerebral oedema with dexamethasone.

Compounding factors In casualties with other injuries, you 2607 These include: will need to increase • Dehydrated personnel due to high sweat loss, fluid replacement. Be careful not to inadequate fluid intake, diarrhoea or vomiting, over-infuse and are at increased risk. generate pulmonary oedema. • Anticholinergic agents (e.g., atropine) inhibit sweating (0237). • A febrile illness, (e.g., septicaemia, malaria) can cause hyperpyrexia leading to misdiagnosis (NB: avoid aspirin). • Heat illness in those suffering other injuries, will worsen shock and increase the risk of renal and other organ failure.

2. Cold Injury

2608 Cold injuries are common in warfare. During WWI, 115,000 British soldiers were affected. This was a major problem during the Falklands campaign. Cold injuries can be systemic (hypothermia) or local. 582

Malaria: see Chapter 24 Chapter_26.qxd 28/09/2004 15:58 Page 583 26: Heat, Cold and Immersion Injury Hypothermia Hypothermia can 2609 Hypothermia is defined as a core occur in <30 minutes temperature (rectal, aural, oesophageal) of in Arctic waters and within 1-2 hour 35°C or less. It ranges from mild to severe: following immersion at 20°C. Cold injury • Mild 35-32°C. takes >20minutes • Moderate 32-28°C. in Arctic. • Severe <28°C. Military causes include: • Reduced heat production due to immobilisation e.g., fatigue, an injured casualty. • Disturbed thermoregulation due to hypovolaemic shock following trauma. • Increased heat loss due to an unfavourable environment and insufficient protection. Wet clothing or immersion in water increases heat loss by a factor of 25, compared to air. Heat is transferred to the surroundings e.g., an injured casualty lying on the ground as opposed to a stretcher. Increasing wind speed worsens heat loss by removing the warm air surrounding the body. At altitude, atmospheric pressure, oxygen tension and temperature (a fall of 6°C per 1000m rise above sea level), are all reduced, predisposing to hypothermia and local cold injury.

Clinical features Assessment of ABC 2610 These can include: in moderate or severe hypothermia • A history of exposure e.g., immersion, avalanche. can be difficult. • Early and non-specific symptoms include hunger, Misdiagnosis of cardiac arrest and fatigue, altered mood or confusion. As body commencement temperature falls there is apathy, hallucinations of external cardiac and psychotic behaviour. Most casualties massage may cause become unconscious between 30-26°C. ventricular fibrillation and death. 583

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• Cold initially causes a tachycardia, constriction of peripheral circulation, shivering and an increased respiratory rate. With decreasing body temperature, there is progressive bradycardia, hypotension and loss of shivering. This may complicate and mask hypovolaemia due to other injuries. Arrhythmias occur below 32°C and may be initiated by external stimuli (2612). Breathing becomes slower and shallower. • Hypothermia interferes with coagulation and delays anaesthetic recovery. Post-operative complications are more likely. • Once unconscious, casualties die from ventricular fibrillation or asystole. Alternatively, In severe they may survive for several hours in a shut hypothermia, survival down state ("metabolic icebox"). In this state, following circulatory arrest for 30 minutes the maxim is:"no one is dead until warm and or more, is possible dead", even if the casualty is cold, stiff, without neurological cyanotic with fixed and dilated pupils and sequelae. no palpable pulses.

First aid 2611 Seek shelter. If one member of a group is hypothermic, others are likely to be similarly affected. In shelter, remove wet clothing and dry the casualty. Re-warm them by body heat from a colleague in a sleeping bag. If this is not possible, keep wet clothes on and insulate them until shelter is reached. Avoid active re-warming in the field. Provide conscious casualties with hot, sweet drinks. 2612 Casualties with severe hypothermia should be triaged T1 for transfer to a Role 3 or 4 facility (0608). Physical movement of these casualties should be done with care and with their legs elevated. Because the hypothermic myocardium has altered electrical excitability, rough handling or cardiac massage may tip those with a very slow heartbeat and low, but survivable, cardiac output into 584 ventricular fibrillation. Chapter_26.qxd 28/09/2004 15:58 Page 585 26: Heat, Cold and Immersion Injury

Resuscitation 2613 Measures include: • Check ABCD (0302). Administer oxygen (0317). • Start CPR if the casualty is apnoeic and pulseless (NB: slower ventilation rate due to the theoretical risk of respiratory alkalosis Heated air/oxygen systems and space predisposing to ventricular fibrillation). Cardiac blankets are of little massage should only be commenced if it can value in re-warming. be maintained sufficiently long for re-warming Invasive techniques to take place. In remote locations requiring that may be of benefit include long transfer times, it may be preferable to peritoneal dialysis, rely on the limited cardiac output likely to haemodialysis and be present naturally. Never start cardiac extra-corporal heat massage and abandon it before re-warming exchange on by-pass. has been performed. • Re-warm. • Uncontrolled re-warming of a chronically hypothermic casualty may result in death due to hypovolaemic shock, acidosis, hyperkalaemia and release of toxins. A useful rule of thumb is not to re-warm a casualty faster than they became cold (i.e., rapid onset hypothermia - rapid re-warming; chronic hypothermia - re-warm over several hours). • For mild hypothermia (conscious, otherwise well) a hot (40°C) bath with limbs immersed produces rapid recovery.

• Do not allow a casualty to stand in a hot shower, Alcohol is a or sit in hot air. Keep them recumbent for at least vasodilator. Its use 30 minutes during rewarming to avoid risks of temporarily delays circum-rescue/re-warming collapse. the cooling of extremities but • Casualties with moderate or severe hypothermia increases the risk of hypothermia. It may should be managed on an HDU/ITU, when they have a role in the are available. Insulate them, including the head. treatment of local Unless the airway is secure, nurse them in the cold injury. recovery position in a warm but, not hot 585

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environment. Tilt the bed a little head down. Monitor fluid balance, serum electrolytes, pH and blood gases. • If casualties are hypovolaemic, carefully infuse fluids at 37-40°C (NB: i.v. cannulation can be difficult!). They may require sodium bicarbonate to combat metabolic acidosis.

Local cold Injury 2614 Neurological (and neurovascular) abnormalities occur during and after local cold exposure of a periphery. There are two clinical entities: 1. Non-freezing cold injuries. Low-reading thermometers should 2. Freezing cold injuries. be available during military operations in cold climates. Non-freezing cold injuries 2615 Non-freezing cold injuries are caused by any combination of: a low temperature (>0°C), moisture (wet footwear due to sweating or immersion), immobilisation and a long exposure time. Pathological changes include arteriolar spasm, microvascular endothelial damage, vascular stasis, hypoxia and deficient cell nutrition. Appearances can be similar to those caused by freezing but, tissue loss is minimal. The lower legs and feet are most commonly affected ("trench foot", "immersion foot"). Features include: • Early (pre-hyperaemic phase; 6-24 hours): the peripheries are cold, swollen, and painful. Pulses may be lost. The skin is white, cyanosed or mottled-red in colour. Numbness and joint stiffness in the feet, make walking difficult. • Intermediate (hyperaemic phase; lasting up to two months): this includes burning pain, red flushing of the skin, bounding pulses, limb 586 swelling, blistering and ulceration. Chapter_26.qxd 28/09/2004 15:58 Page 587 26: Heat, Cold and Immersion Injury

• Late (post-hyperaemic): includes cold sensitivity, pain and paraesthesia (may prevent walking and wearing of boots), hyperhydrosis and poor skin quality. Chilblain (pernio) is commonly seen in military personnel at high altitudes following exposure to dry temperatures just above freezing. The fingers and nose are usually affected. Skin redness and hypersensitivity are typical and may proceed to blistering and ulceration. Treatment of non-freezing cold injuries is to remove wet boots and socks, followed by bed rest, limb Suspect local cold injury in those elevation and slow re-warming. Leave blisters intact. injured and Keep affected areas clean and dry - use loose immobilised in dressings or a plastic bag. Give antibiotics (0816), the cold. Treat life- anti-tetanus (0828) and analgesia (Figure 0701). threatening hypothermia as a Transfer as a stretcher casualty. At role 3 or 4 the higher priority than feet can be washed in warm water (2617). local cold injury. Because treatment is difficult, prevention is important. This means dry socks and footwear, insulated insoles, avoidance of constriction around limbs and extra care when working in wet environments. Local freezing injury Freezing cold injuries can result from contact with cold 2616 Clinical features metal e.g., the casualty's weapon. • Freezing cold injuries occur at temperatures below 0°C. Initially, there is vascular spasm Where the injury and stasis, progressing to the formation of is both freezing and non-freezing, extracellular and intracellular ice crystals. treat as for the Clues include: a history of cold exposure and the dominant type; presence of ice on the skin and in clothing e.g., where neither the casualty's socks. Freezing cold injuries are dominates, treat as for a freezing injury. often seen in association with hypothermia, Continue immobilisation or peripheral vascular re-warming. compromise due to injury and dehydration. Immobilise and Commonly affected sites are the hands, feet, protect the affected part. cheeks, nose and ears. Three subdivisions 587 are recognised: Chapter_26.qxd 28/09/2004 15:58 Page 588 26: Heat, Cold and Immersion Injury

• Frostnip: is incipient freezing injury which recovers fully within 30 minutes of re-warming. The typical appearance is that of a white spot. The importance of differentiating frostnip from frostbite is that the former should be re-warmed slowly using the skin-to-skin method (place the casualty's hand in their groin or axilla or, for a foot, seek buddy-aid!). Do not rub the affected areas - friction can damage the skin. Immobilisation is not required. • Superficial frostbite: this is limited to the skin. Affected tissue is pale/waxy-white and numb. • Deep frostbite: the skin turns white and marble-like, feels hard and adheres to adjacent tissues. Deeper layers are wooden (NB: estimating depth is difficult). • Severe freezing injury results in varying degrees of necrosis (skin, muscle, bone) and loss of function. In the first 24 to 36 hours, there is tissue oedema and blistering. If uninfected, Defrost frostbite the blisters blacken and dry and eventually rapidly. Re-warm slough-off leaving pinkish-red thin skin. non-freezing Where the entire digit is affected, mummification injuries slowly. and auto-amputation may occur. Do not hasten amputation until the line of demarcation is clear. • Late complications of freezing injury include prolonged disabling cold sensitivity, paraesthesia and chronic neuropathic pain.

2617 Management of freezing injuries • Remove casualties from the scene (a sense of urgency should prevail). Extremities must only be re-warmed once the casualty has reached a safe, warm environment: maintain body heat and minimise heat loss. Make sure the sequence 588 'freeze-thaw-refreeze' does not take place.

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• Management of frost nip - see 2616. • In true freezing injuries, resuscitate with warm If essential to i.v. crystalloids and re-warm rapidly. Immerse the survival, the casualty may walk on their affected extremities fully in stirred water frozen feet, but not maintained at 41°C (38-42°C). Add a topical after thawing or anti-bacterial agent (e.g., aqueous chlorhexidine) re-freezing: there to the water bath to reduce skin contamination. is an increased risk of tissue loss and • Keep limbs immersed for at least 30 minutes. infection. It takes longer than you think to bring the temperature of the affected parts up to a minimum of 30°C. The affected limb should be dried carefully, immobilised and protected from trauma (e.g., cotton wool pledgets between toes). Leave blisters undisturbed. If possible, nurse exposed on sterile sheets and protect with a bed cradle. • If freezing is deep, circumferential and involves the lower leg or forearm, perform a fasciotomy prior to thawing (0908). This will prevent a rise in compartmental pressure and further tissue necrosis, as ice crystals expand (NB: fasciotomies may bleed profusely following rewarming). • Thawing is often painful. Paracetamol is usually sufficient analgesia but morphine may be required (Figure 0701). Oral alcohol (double or treble measures of spirits) reduces the need for analgesics and may improve outcome by increasing peripheral blood flow. Epidurals using 0.25% bupivacaine will cause peripheral vasodilation and relieve pain but, may be impractical in the field. • Where there is likely to be significant tissue necrosis, administer antibiotics (0816) and tetanus prophylaxis (0828). • If available, hyperbaric oxygen improves outcome where tissue viability is compromised. Vasodilators are of no proven benefit. 589

Analgesia: see Chapter 7 Chapter_26.qxd 28/09/2004 15:58 Page 590 26: Heat, Cold and Immersion Injury Casualty transfer and subsequent care 2618 • Insulate and protect extremities before transfer. • Freezing injuries need twice daily 'whirlpool' baths (41°C, 30 minutes, add topical antibacterial) and protection from infection (e.g., antiseptic-soaked dressings between the toes). • Do not aspirate or deroof blisters (contents are sterile). Trim blisters only if sepsis supervenes. Keep casualties exposed on sterile sheets and protect from bedclothes. Rest, good nutrition and physiotherapy are important. • Because of the compromised vascular supply, avoid surgery to the injured part for at least 5 months. Exceptions include: infected wounds, freeze-thaw-refreeze trauma, or where there are complications secondary to other injuries. Delay amputation until demarcation is complete (>10-12 weeks). Limitation of joint movement may require an escharotomy. • Pain relief, particularly for nocturnal pain, can best be achieved with an oral night time dose of amitriptyline (start with 50 mg increasing to 150 mg as necessary -unlicensed indication). Other analgesics are generally ineffective. • Follow-up by a cold injury clinician is essential to minimise the risk of disabling sequelae.

3. Near Drowning

2619 Near drowning is asphyxia due to inhalation of water. It commonly occurs in those who become mildly hypothermic. Typically, immersion was brief, the water rough, and no lifejacket was worn. 590 Chapter_26.qxd 28/09/2004 15:58 Page 591 26: Heat, Cold and Immersion Injury 4. Secondary Drowning

2620 Secondary drowning is an uncommon Aspiration of water adult respiratory distress syndrome resulting from (especially if inhalation of water. Onset may be delayed; it is often contaminated e.g., harbours), rapidly fatal. Features include: commonly results • Sudden or rapid onset of dyspnoea, in pneumonia. cough, haemoptysis and respiratory distress. • Occurs up to 72 hours after (usually uneventful) immersion. NB: warn casualties who may have Suspect secondary aspirated water to watch for features of drowning in secondary drowning. casualties who develop respiratory Management is administration of oxygen and urgent distress following transfer to an ITU. Early ventilatory support can recent immersion. be lifesaving.

591

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Military Psychiatry

Acute Psychological Reactions to Combat

Acute stress reactions (ASR) 2701 ASR's are uncommon, reversible, It must be psychological reactions to extreme stress; remembered that they interfere with an individual's ability to function. most individuals Removal from events will allow recovery. If respite is do not develop either impossible, symptoms will diminish after approximately acute or post combat stress reactions 72 hours.The incidence of ASRs occurs in 10-30% of or disorders. personnel involved in a land campaign. ASR are most likely when things are going wrong e.g., where avoidance (or action) is impossible and large numbers of casualties are being taken.

Acute psychiatric disorders (APD) 2702 This group of clinical psychiatric disorders may or may not be reversible. APDs include: • Psychotic breakdown (2715). • Dissociative (hysterical) disorders (2718). • Somatisation (2719). • Malingering and factitious illness (2720). In combat psychiatry, whilst there is no need for a psychiatric diagnosis, an attempt should be made to exclude an organic cause (2714) and to assess the casualty's danger to themselves (2716) and others (2704). An APD in forward areas will become apparent when the condition does not respond to simple rest and respite. 593 Chapter_27.qxd 28/09/2004 15:58 Page 594 27: Military Psychiatry

Symptoms Combat is a dangerous place 2703 Psychic distress in combat manifests to lose 'self-control' itself by changes or incongruities in behaviour. and like courage fear is 'contagious' within The clinical picture is usually mixed and confusing. a unit. Therefore Symptoms include: individuals must be managed quickly, • Fear and anxiety. professionally and firmly. • Irritability, agitation. • Hyper-vigilance. • Anger and rage. • Grief, guilt, self doubt. • Somatic complaints. • Carelessness, poor concentration and memory. • Insomnia. • Emotional volatility. • Fugue states (amnesia and wandering). • Illusions and hallucinations.

Violence 2704 Gross behavioural dysfunction requires immediate attention: violence is rare in ASRs, but common in organic (e.g., exposure to chemical weapons, treatment with atropine) and personality disorders. • Remove the casualty's weapons. • Look for an organic cause. • Restraint may be either physical or chemical. • Physical restraint requires five people and should be accompanied by reassurance and reorientation. • Drugs may be required to defuse the situation. The choice will be between either: 594 Chapter_27.qxd 28/09/2004 15:58 Page 595 27: Military Psychiatry

• a neuroleptic which tranquillises without impairing consciousness (e.g., chlorpromazine, flupenthixol, haloperidol). and/or • short acting anxiolytic (diazepam, lorazepam).

Evacuation syndromes 2705 Transferring the casualty with ASR symptoms too soon, or too far back in the chain, potentially risks long term mental ill health. The aim must be to keep individuals close to their comrades, yet out of direct fire. ASRs diminish force levels and casualty removal puts a strain on those left behind and potentially increases the risks they face, it is therefore important for the unit to receive their men back as soon as possible. It is equally important for the individual to return to their comrades and their job to avoid feelings of shame and guilt.

Mental State Examination and Triage

General 2706 Mental state examination in the field is an attempt to try to fit the behaviour (verbal and non-verbal) to the symptoms. The aim is to assess whether the individual is manageable close to the front with their comrades, or will have to be transferred. This may be limited to: Is the individual a danger to themselves or others? • Ask directly. • Remove weapons. Is this organic? • Is there alteration in conscious level? • Visual and olfactory hallucinations? 595 Chapter_27.qxd 28/09/2004 15:58 Page 596 27: Military Psychiatry

• Seizures? • Evidence of exposure to chemical weapons? Is this psychotic? • Are their actions (behaviours) understandable and congruent with their thoughts (as revealed in speech)? • Is there disorder in the form (linkage) of thought? • Is there disorder in the content, and if so, does this disturb them e.g., delusions? • Are there perceptual disturbances, and if so are they disturbing e.g., hallucinations? Is this malingering? • Difficult! What are the gains and losses this individual will experience? • Do the symptoms match the story and mental state?

Credibility 2707 Military psychiatrists must have expertise in excluding physical causes for psychological symptoms. A physical examination is mandatory when an individual requires holding or referral. It is axiomatic that non-psychiatrists should also develop an understanding of how to take a simple mental state examination. Credibility will also be enhanced if psychiatrists do not force those they are dealing with to accept a psychological, rather than physical, cause for their suffering.

Management of ASR

In the field 2708 This is summarised by two simple acronyms:

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1. PIES Treatment of ASR should be •Proximity. undertaken as close to the front •Immediacy. as possible; as quickly as possible •Expectancy. with the expectancy that the individual is •Simplicity. not suffering from a mental illness and 2. The 7 Rs will return to duty. •Recognition. •Respite. •Rest. •Recall. •Reassurance. •Rehabilitation. •Return.

2709 Considerations include: Assessment: exclude organic and serious psychiatric disorder. Reassure: explain to the individual that their emotional and psychological feelings are normal, temporary and reversible. Medication: drugs are best avoided as they will confuse the clinical picture and interfere with memory and concentration. Drugs risk the development of state dependent learning and potential wastage of time and resources. Short acting hypnotics are occasionally indicated. Psychotic individuals will require neuroleptics. Transfer: Manage with the expectancy that the individual will return to some form of duty. Extremely disturbed individuals may have to be sent rearward. They should spend no more than 48 hours at each holding area throughout the chain of evacuation. 597 Chapter_27.qxd 28/09/2004 15:58 Page 598 27: Military Psychiatry

Avoid admission to medical wards as this may increase the risk of long-term mental illness.

Prevention Primary 2710 The psychosocial health of the Unit is the bastion against mental breakdown in combat. Every effort must be given to the development and maintenance of esprit de corps built on tough realistic training, trust in comrades, the chain of command, equipment and attention to welfare issues. There is, however, no sure way of knowing how individuals will act on the day.

Secondary 2711 The early recognition of ASRs and the institution of management strategies as rapidly and as far forward as possible, in order to return individuals to duty as soon as possible, whilst maintaining their social role. Rapid segregation and psychological management of dramatic cases and disciplinary management of mailngeres, must be instituted to prevent 'Contagion' and deter secondary gain.

Tertiary 2712 This is the management and treatment of established mental disorders and is not a front line activity.

Physical Injury and Psychiatry

2713 Considerations include: • The initial 'euphoria' of having survived an injury may give way to guilt and shame if comrades have died, or remain behind under great threat. 598 Chapter_27.qxd 28/09/2004 15:58 Page 599 27: Military Psychiatry

• As the consequences of disability become apparent the individual may become irascible, irritable and withdrawn and uncommunicative. • Injuries which are likely to cause psychological problems include blindness, amputations, disfigurement, genital wounds, burns and paralysis. • There is likely to be a degree of distress or anxiety at the prospect of returning to duty for those individuals who have had less major injuries and are now fit for service.

Organic Causes of Symptoms

2714 These include: Infectious disease Thermal and metabolic injury The first signs of heat and cold injury may involve changes in behaviour (2602, 2610). Atropine can lead to thermal injury (0237) and is particularly dangerous in hot climates, when sleep deprived, physically exhausted and at increased doses.

Central nervous system Military psychiatrists should be familiar • Head Injury: Acute head injuries can with assessing GCS. mimic psychiatric disorders and the level of consciousness of a casualty must be assessed over time. Many head injury sequelae can lead to psychological difficulties. Military psychiatrists should be adept at managing and advising on these conditions. • Paralysis: Hysteria or malingering may mimic paralysis or paresis. • Seizures: One of the commonest causes of seizures is alcohol withdrawal and/or head injury. Pseudoseizures may be seen in malingering and 599

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dissociative disorders (hysteria), interestingly they are more common in individuals who have epilepsy. • Delirium. Delirium may prove fatal if misdiagnosed and treated as a psychiatric condition. Always look for a physical cause. Delirium should be considered when there is fluctuation in conscious level, sleep disturbance, agitation and hallucinations.

Intoxications • Substance misuse: consider in any differential diagnosis of altered behaviour. • Atropine: CNS effects occur at high doses e.g., hallucinations and disorientation (0237). • Chemical agents: chemical weapons can cause miosis and eye pain (0233). This can be prevented by pyridostigmine prior to exposure (0234). Miosis is also seen in opiate misuse. Chemical weapons may alter the epileptic threshold.

Abdominal trauma Peritonism may lead to individuals assuming a foetal position and immobility. This may mimic uncooperativeness or malingering.

Aural trauma Deafness is common following explosions. Similarly, deafness may be mimicked in malingering and dissociative disorders.

Occular trauma Laser eye injuries can lead to (painless) blindness. This may also be encountered in dissociative disorders and malingering. Blindness is particularly 600 terrifying in a combat situation.

Head injury: see Chapter 16 Chapter_27.qxd 28/09/2004 15:58 Page 601 27: Military Psychiatry Psychological Disorders

1. Acute Psychotic disorders

2715 These are no more common in combat than The key to psychotic in peacetime: illness is its 'non- understandibility' • The diagnosis is usually straightforward and incongruity. as behaviour is grossly disturbed and usually congruent with the underlying psychiatric disorder. • Attempts at feigning a serious mental illness may be encountered. • Numerous cases may raise the suspicion of chemical agent.

Suicidality 2716 It is vital to assess an individuals risk of suicide: • Worries and problems at home and in theatre can lead to mental distress and inappropriate behaviour. • One of the psychological hooks which keeps military personnel going through difficult times is a belief, whether realistic or not, that there will be something worthwhile at home to return to. • Bereavement in combat can be a potent cause of survivor guilt. Depression should always be sought and suicidality raised when biological symptoms are present. • Sleep deprivation is a common cause of lowered mood, and so a therapeutic trial of rest, sleep and respite may see a restoration of mood and diminution in suicidal thoughts.

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Personality disorders 2717 Diagnosis can be difficult. • It is generally made on evidence of previous If behaviour has behaviours; these individuals seem unable recently changed, then an organic to profit from experience. cause should be • Individuals with personality disorders cause sought. distress for both themselves and those with whom they work (e.g., annoyance, irritation, frank disbelief). They can disrupt a unit by setting comrades against each other. They may also be masters at avoiding blame, or the responsibility for their actions. • If individuals misbehave, they should be dealt with through the disciplinary, not medical chain.

Dissociative disorders (hysteria) 2718 These conditions are occasionally encountered: • Presentation may include blindness, deafness, altered sensation and paresis. • Search for an organic cause. • Any stay in hospital should be as brief as possible, if individuals are not to 'pick up' further medical conditions, or fail to improve.

Somatisation 2719 The presentation of physical symptoms as a manifestation of psychological symptoms is very common in time of conflict, and not a fully conscious process. Excessive focus on the physical, unnecessary investigations and inappropriate transfer may lead to long term mental ill health and disordered illness behaviour.

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Malingering and feigned illness 2720 A high index of suspicion is required as its management is disciplinary not medical.

2. Post combat or traumatic 2721 Post traumatic mental reactions are the norm, but a few will lead to post traumatic mental disorders. • Post traumatic stress disorder (PTSD) is one of these disorders and may occur in up to 30%. The pillars of the post traumatic reaction and PTSD are re-experiencing, avoidance and arousal. Associated behaviours such as risk taking, misuse of alcohol, relationship problems also occur. • Other long term complications include depression, anxiety, substance abuse, phobias, personality change and medically unexplained symptoms (MUS) with associated abnormal illness behaviour.

2722 The aetiology of non-psychotic mental illness is multifactorial and is the product of an interaction between the: • Individual's personality and experience. • Traumatic stressor. • Environment in which the event was experienced. • Environment afterwards. • Culture from which the individual comes and to which he returns.

2723 As in ASRs and APDs, only a minority of individuals develop a problem. • Many are treatable with existing therapies and medication. Early referral is recommended. 603 Chapter_27.qxd 28/09/2004 15:58 Page 604 27: Military Psychiatry

• At present, there is no evidence that interventions soon after the event, such as Psychological Debriefing, work; indeed there is a suggestion they may do harm. • MUSs are therapeutically challenging and difficult to manage.

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Major Incident Medical Management

Definition

2801 A major incident for the medical services is: Any incident where the number, severity, type or location of live casualties requires extraordinary resources. A major incident for a multinational deployed force is one where: A single nation's medical assets are unable to cope with the casualty load. The "extraordinary resources" in these circumstances are another nation's assets. The three phases of a major incident are: 1. Preparation. 2. Response. 3. Recovery.

1. Preparation for a Major Incident "If one fails to plan, then one is planning Preparation requires planning, equipment and training. to fail".

Planning 2802 Advance formulation of a major incident plan is essential to a successful outcome. A generic "all hazards" plan has been designed for a multinational NATO Force deployed on a peacekeeping operation (Hodgetts TJ. KFOR Generic 605 Chapter_28.qxd 28/09/2004 15:58 Page 606 28: Major Incident Medical Management

Major Incident Planning Guidance, Kosovo 1999). This provides a useful template for major incident planning by clinicians on operational deployment. A series of NATO Medical STANAGS (standing agreements) provides the framework for components of the military major incident response.

Equipment 2803 This includes appropriate safety clothing and advanced life support equipment as supplied by incident response teams (Table 2802).

Training 2804 Training encompasses both education and exercise: • Educational courses should address scene management of multiple casualties (e.g., Major Incident Medical Management and Support MIMMS) and treatment (e.g., Advanced Trauma Life Support ®; BATLS). • Medical units should regularly exercise triage, clinical co-ordination, communications, treatment of various injuries in different settings, trauma documentation, and interservice working arrangements. Exercises may be: • Paper. • Table-top. • Practical with or without simulated live casualties. • Interservice.

606

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2805 The following seven priorities apply to all emergency services, whether civilian or military anywhere in the world: •Command and control. •Safety. •Communication. •Assessment. •Triage. •Treatment. •Transport. The aim is to impose order on a chaotic major incident.

Command and control

2806 This involves: Major incidents involving chemical • Command is exerted vertically within the spillage, radioactive emergency services. Each service at the scene contamination or will have a commander, referred to as the Incident biological agents Officer (e.g., Medical Incident Officer MIO). need specialist input. • Tiers of command. Control at the scene is facilitated by the use of inner and outer cordons, commonly marked by tape. These cordons identify levels of command at the scene. • Bronze. This is the immediate area of the incident, marked by an inner cordon. There may be several "Bronze" areas. A forward commander may be appointed to work within each. • Silver. The outer cordon marks the area of responsibility of the Incident Commanders (who form the "Silver" level of command). 607

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• Gold. Strategic command (e.g., at Brigade HQ) is designated "Gold" command. • Control of a major incident is exerted horizontally The Fire Service is responsible across the emergency services. Overall there for safety following will be one individual (or service) in control. chemical spillage. In the UK this is usually the job of the Police. Where there is fire, chemical or other hazards this role will be assumed by the Fire Service within the immediate area of the incident. On military operations abroad, the Explosives Ordnance Disposal (EOD) may take local control in areas where mines or other unexploded ordnance are a threat, with the battle group being in overall charge.

Safety

Medical and rescue 2807 The priorities are Self, Scene, and personnel are at risk Survivors ("1-2-3 of Safety"). Get out and stay of secondary devices out of the contaminated area. Personal should use in terrorist incidents. appropriate protective equipment. Safety of the scene is enhanced by effective control of the cordons. Inform the Incident Commander (2806) about any of the following: • Difficult assess: approach may be required by rotary wing, specialist vehicle or on foot. • Unsafe vehicles: ensure the ignition is turned off, the battery disconnected and the fuel supply isolated. Help may be needed from the engineers to secure an unstable vehicle. • Trapped casualty: this may require cutting equipment and assistance from the Fire Service. • Possible hyper- (2604) or hypothermia (2611) amongst staff and casualties. • Hazards: high tension cables, flooding, fire, chemicals (NB: you may need to wear IPE0228), unexploded munitions, weapons at scene 608

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(e.g., casualty's personal weapon) and suspected booby traps. • Ambush or hostile local population.

Communication 2808 Communications have consistently been identified as the main failing in major incidents. This applies both vertically and horizontally within the chain of communications. Incident commanders must ensure they communicate frequently with their counterparts in other services, as well as with their forward teams. The MIO should be in contact with the hospital clinical co-ordinator via the appropriate chain of command.

Assessment 2809 The first message from the scene should follow the METHANE format to ensure that essential information is passed on: M My call sign; Major incident "Standby" or "Declared" E Exact location Grid reference T Type of incident H Hazards Present and potential A Access Roads, landing areas N Number of casualties Including severity and type E Emergency services Present and required

Triage All Role 1 and Role 2 operational 2810 The aim of triage in a major incident is to units and Incident sort casualties according to medical priority, so that Response Teams limited medical resources can be directed to those should be equipped most in need of treatment (0603). Triage is a dynamic with sufficient DMS-approved process that needs to be repeated several times triage cards. 609

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during the stages of care. A more refined "triage sort" (0608) can be used at the casualty clearing station to prioritise transfer.

Treatment 2811 The aim of treatment at the scene is to allow the casualty to reach hospital safely. It may be preferable to "scoop and run" rather than "stay and play". Life saving first aid is provided in the immediate vicinity of the incident. Advanced life support measures are carried out at the Casualty Clearing Station. Setting the latter up at a safe distance from the scene of the incident is the responsibility of the Ambulance Incident Officer.

Transport 2812 Transfer following a major incident aims to "get the right casualty to the right place in the right time". Do not simply move the major incident from the scene to the hospital. Casualties should be dispersed to different hospitals depending on their capacity, the specialist care available and the logistics of transportation.

The dead 2813 Dead casualties should be clearly labelled during the triage sieve. A major incident is often regarded as a crime scene. The dead should not be moved except to gain access to the living or to prevent destruction of a body by fire or chemical. Death should be officially pronounced by a medical practitioner and witnessed by a police officer. The police are responsible for identifying the dead, informing relatives and removing bodies from the scene.

610

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Planning 2814 A major incident plan must be formulated and regularly exercised and updated. This may require planning and liaison between co-located medical units of different nationalities and between civilian and military facilities. In war fighting, a field hospital will permanently be in a heightened state of readiness.

Incident activation 2815 In the UK the following messages to the hospital have been standardised: • Major incident - standby. This alerts the hospital that a major incident is possibly imminent or is unconfirmed. Key personnel are to be informed. • Major incident declared - activate plan. The incident has occurred and a full response is required. • Major incident - Stand down. Return to normal activities.

Command and control 2816 During a major incident there is a need for central clinical command and administrative control. If available, an emergency physician would take command of the clinical response, with the hospital commander exerting overall control.

Communications 2817 The clinical co-ordinator at the hospital requires timely and accurate information from the scene. They need to know the approximate number and nature of casualties, their probable time of arrival 611 Chapter_28.qxd 28/09/2004 15:58 Page 612 28: Major Incident Medical Management

and when no more are to be expected. This allows reasoned decisions to be made on the usage of key resources.

Triage 2818 The triage sieve should be used to direct casualties to the most appropriate areas (0603).

Treatment of non-critical casualties 2819 There are two distinct stages of hospital management: Stage 1 This occurs as the incident is evolving, casualties are arriving, and the scale of the incident is unknown. The priority is conservation of key resources for an unknown number of critically injured casualties, whilst at the same time providing minimal acceptable care for all others. Stage 2 Occurs after all casualties have arrived, their injuries have been defined and hospital resources are fully mobilised. Definitive care can now be provided to all according to triage priorities.

Treatment of critical casualties 2820 Damage control surgery aims to provide minimal intervention to save the lives of the most critically injured casualties (0402). Treatment is directed at treating airway and breathing compromise, staunching haemorrhage and temporary control of hollow visceral injuries. Definitive care is delayed for 24-48 hours until the casualty is more stable and fresh resources are available (0403).

A note on blood transfusion 2821 Experience in war and disaster scenarios has shown that most injuries do not need transfusion 612 (the major exception being amputations), and that the

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transfusion trigger can safely be lowered to a haematocrit of 21% (Hb 7-8g/dl). Because a field hospital has a limited blood bank and no facilities for platelet infusion, clinicians should have a higher threshold for initiating transfusion during a major incident. Freshly donated warm blood, with its full complement of platelets, can be life saving for casualties with severe wounds who have entered "the bloody vicious cycle" of profound hypothermia, coagulopathy and metabolic acidosis (Figure 0401). An emergency blood donor panel should be set up at the start of operational deployment.

A note on investigations 2822 Radiographic triage is often necessary The logistic during receipt of mass casualties. X-rays are routine problems associated following polytrauma (0336). More specialised with replenishing investigations may be necessary (0337). stocks of oxygen and blood used during a mass Transfer casualty incident 2823 Following a major incident it is necessary to: on overseas deployments • Restore the ability of the medical unit should not be underestimated. to accept further casualties. • Transfer casualties for definitive care. Experience from major incidents involving British military medical units in the Balkans and Sierra Leone has shown that it takes between 28 and 30 hours from the time of the incident to when the last casualty is transferred from the facility. This is known as the "30 hour/next-day rule". A major incident does not cease on transfer of casualties to definitive care. Specialised care well go on for weeks or months and considerably impact on the normal workload of the Role 4 hospitals.

613

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The Incident Response Team and Aeromedical Evacuation

1. Incident Response Team

Introduction 2901 During operations in areas where infrastructure is limited, immediate BATLS care and evacuation (transfer) may be provided by Incident Response Teams (IRT). Essential features include: • Trained personnel and appropriate resources on constant standby. • Rapid communication from incident to deploying authorities, vehicles and IRT. • Rapid, safe access to the incident with appropriate incident control (2806).

Requirements 2902 Considerations include: • The configuration of the IRT depends on the population at risk (PAR), likely threat local factors. • Trained personnel with the skills necessary to care for critically injured casualties in the pre-hospital environment (Table 2901). At a major incident one of these would act as Medical Commander (Medical Incident Officer 2806). When responding to small incidents, only one medical officer may be dispatched e.g., an anaesthetist. Relevant equipment is listed in Table 2902. 615

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Medical personnel Medical Consultant Anaesthetist require advanced Consultant Intensivist airway management skills, including use Consultant in Accident of induction and and Emergency Medicine maintenance drugs. Nursing Intensive Care Isolated ability to Accident and Emergency perform rapid sequence induction Professions Allied to allow intubation is to Medicine Operating Department Practitioner insufficient, as this is Paramedic only a small portion Medical Assistant of overall airway management. Support Administration Signals Fire Service Explosive Ordnance Disposal

Logistic Drivers Aircrew

Security Police Ground Forces

Table 2901. Optimum composition of an IRT.

• In order to provide a secure environment, additional staff such as Explosive Ordnance Disposal (EOD), military police and Defence Fire Service are required. Training with these and other team members will ensure a coherent approach to casualty care and mission safety. • Where IRT is to be conducted using rotary wing aircraft, all personnel must know about aircraft safety (2923) and have had experience in winching. • In hostile environments (e.g., continued enemy activity), specific training such as Isolation Preparation (ISOPREP) may be necessary.

616

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Generic Specific Electrical and gas powered equipment Medical Airway support Masks, OPA, NPA, ET, can be dangerous cricothyroid puncture kit. and must be cleared Suction High performance, for use on military battery powered. aircraft. Likewise Oxygen Regulators with high and aircraft systems low pressure connectors may affect medical for all types of delivery. equipment. Cervical spine Collars, blocks, tape. immobilization Vacuum mattress /spinal board Tube thoracostomy Military pattern, without trocar. During the Israeli i.v. access Large bore cannulae. campaign in South Lebanon, there Fluids Crystalloid, colloid, blood. were 1.7 injuries Drugs Resuscitation, maintenance. per casualty. Prior Multifunction monitors ECG, SpO2, NBP, to evacuation temperature as a minimum interventions (2530) included: applying a dressing (26%), Defibrillator establishing an External pacing i.v. line (28%) and Warming Heated overblanket with ventilation (21%). battery power. The average on Ventilator Adjustable for tidal volume scene time for and frequency, with aeromedical pressure monitoring as evacuation was a minimum (see 2531). 3 minutes.

Personal Clothing suitable for location and task Combat body armour Combat helmet /flying helmet Immediate survival Water, rations, e.g. following forced locator beacon, landing secure communications

Weapon e.g. pistol Communications At least at level of vehicle to Operational control. Vehicles Wheeled, tracked, rotary wing

Table 2802 Equipment for IRT. 617

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Attendance at major incidents Callout can be distressing for the careers. Look 2903 Inadequate information and poor out for acute co-ordination may resulting in over reaction to psychological a situation, or failure to initiate callout in medically reactions. Symptoms significant incidents. UK Forces use the "METHANE" are listed in 2703. These can often be system (2809) to ensure that essential information is prevented by passed on from the scene. effective team support. Incident safety 2904 Considerations are discussed in 2807

Intervention and packaging 2905 Patterns of injuries likely to be encountered are discussed in 0101 and 0102. The level of initial intervention is the minimum that will stabilise the casualty for safe transfer (2811). This is often a compromise between "scoop and run" and "stay and play". The essential factor is the speedy and safe transfer to better facilities. Types of intervention are described in 0317-0338. If you think one or more of these are essential, they are best carried out on the ground before transfer. Trying to obtain i.v. access or insert a chest drain in a moving airframe is difficult! Preparing the casualty for flight is essentially the same as the "packaging" of any casualty for movement (0338): • Monitoring must be established and maintained. • The casualty must be secured to the stretcher, and the stretcher secured to the aircraft. Where effective immobilisation is required, a vacuum mattress is less likely to cause pressure sores during prolonged transfer than a spinal board; it may be easier to load and unload.

618 • All ventilated casualties should have a naso-or

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orogastric tube to decompress the stomach. This will help reduce the effect of gas expansion during flying and the likelihood of reflux.

Record keeping and handover 2906 Despite the urgency of the situation, it is essential that adequate records are kept. The minimum information required is summerised by the acronym 'MIST' (0301). This can be conveniently recorded on plastic triage labels, 'T'cards or FMed 826. Details of MIST must be passed on following arrival at the medical facility. After handover the IRT team should clean their equipment and replenish consumables. If the incident requires more than one trip for the team, pre-packed selections of the most commonly used items are useful to speed the re-supply and preparation process.

2 Aeromedical Evacuation

Tactical and strategic aeromedical evacuation 2907 The movement of casualties, other than immediately following injury, falls into the category of secondary transfer. This is should be a process of "seamless" delivery of care. By this stage most Current medical employment of casualties will have undergone resuscitation +/- air transport in the damage control surgery. Transfer times are likely forward area is to be prolonged. based on NATO Standardisation Agreement 2908 Casualties are categories according to (STANAG) No 2087. Table 2903. Transfer is undertaken by Aeromedical This agreement Evacuation Squadrons using dedicated aircraft and defines who, how, medical teams. Evacuation of those in Category 3 when and where casualties can be and 4 is reasonably straightforward. Casualties in evacuated from the Categories 1 and 2, require active delivery of care by battlefield. staff with high dependency and intensive care skills. 619

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At tactical level, transfer between Role 2 and Role 3 would involve RAF Critical Care Air Support Teams (CCAST). Co-ordination of this system is via Air Evacuation Co-ordination Officers (AECO) and Air Evacuation Liaison Officers (AELO - attached to each Field Hospital). These personnel should be deployed early in the initial stages of all UK operations and form the forward elements of the air evacuation chain.

2909 Strategic aeromedical evacuation is potentially most demanding. In a hot extraction situation, where there is danger to the aircraft and British forces in Malaya in the late personnel, adopt a 'scoot and run' approach. 1940's were amongst Typically, there will be limited opportunity for clinical the first to utilise intervention, other than clearing and maintaining the helicopters for airway. Casualties are often loaded without the aid casualty evacuation. During the Korean of a stretcher and may need to be fixed to the floor conflict over 20,000 of the aircraft. wounded were evacuated strapped Onward travel to the UK is by fixed wing aircraft. to stretchers outside Evacuation may require full intensive care to be the cockpit. provided for up to 24 hours and in various modes of transport. . Potential in-flight problems 2910 These include • Dislodgement of endotracheal tubes, i.v. lines and monitoring equipment. . • Altitude and the effects on oxygen tension and gas expansion. • Temperature. • Acceleration and deceleration. • Vibration. • Noise. • Motion sickness. 620 Chapter_29.qxd 28/09/2004 15:58 Page 621 29: The Incident Response Team and Aeromedical Evacuation

Category 1 Intensive care, requiring ventilation 2 High dependency care, intensive monitoring 3 Requiring infusions, catheters, drains 4 Essentially "walking wounded"

Table 2903 NATO categorisation of Aeromed casualties.

Altitude

2911 Atmospheric pressure falls with increasing Dedicated helicopter altitude; this relationship is not linear. Ambient squadrons were first atmospheric pressure halves at 18,000ft (~6,000m) introduced by the and halves again at 33,000ft (~10,000m). This means US military. The more than 400,000 that the higher the ascent, the less oxygen there is casualties airlifted available and a given amount of gas expands to fill during the Vietnam a larger volume. War demonstrated the value of rapid Current fixed wing aircraft used for evacuation extraction and fly at an altitude between 26,000-35,000ft (~9,000- early delivery to 12,000m). To save fuel and reduce flight times, cabin a surgeon. pressure is generally maintained at levels equivalent to an altitude of 6,000-9,000ft (~2,000-3,000m); this rarely causes symptoms. By comparison, reduced oxygen tension may be critical in a shocked casualty or one with lung trauma. Similarly, expansion of air in body cavities (e.g., skull, chest or bowel) may have disastrous consequences (see below). Altitude is less of an issue in helicopter flights where most evacuation is carried out between 1,000-6,000ft

(300-2,000m) and flying times are usually shorter. Following injury, one of the most Temperature dangerous times for the casualty is during 2912 The internal temperature can be transfer. The airway controlled during most flights by fixed wing aircraft; may become hypo/hyperthermia is not generally an issue. This is obstructed and tubes/lines kinked, not usually possible during helicopter transfer, where disconnected or fall wind chill means that external temperatures can out. Movement of reach - 40°C. Medical personnel need to be sensitive wounds and to likely changes in the casualty's body temperature fractures results in pain and increased and vary the number of blankets accordingly. This is bleeding. 621

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especially important in the already hypothermic casualty, or following burns and spinal trauma.

Acceleration/Deceleration 2913 Two types of acceleration are experienced in a helicopter, linear and radial, both of which may affect cardiovascular function. • Linear acceleration: results from an increase or decrease in the rate of movement along a straight line. A stretcher casualty, lying parallel to the long axis of the airframe will experience a shift of blood fluid volume towards the lower extremities, stimulating baroreceptors and resulting in transient tachycardia. • Radial acceleration: occurs due to a change in direction of motion. A banking helicopter causes a uniform increase in gravitational force acting outwards from the centre of the turn (measured in Gs). This will increase hydrostatic pressure in vessels below the level of the heart, impairing venous return and thus dropping cardiac output (Starling's Law). The physiological responses that follow mimic those seen in hypovolaemic shock. This could have serious consequences in a casualty who is already hypovolaemic.

Vibration 3914 Vibration is an inevitable feature of helicopter flight and can have a number of pathophysiological effects: • Prolonged exposure to low frequencies can result in blurred vision, shortness of breath, chest/abdominal pain, motion sickness and fatigue. • interference with the body's ability to thermoregulate, e.g., by causing vasoconstriction and decreased ability to sweat. Consequently, 622 Chapter_29.qxd 28/09/2004 15:58 Page 623 29: The Incident Response Team and Aeromedical Evacuation

helicopter transfer may impair cooling mechanisms in a hyperthermic casualty. • Increased wound pain, fracture movement and bleeding leading to increased requirements for analgesia and fluid resuscitation.

Vibration can interfere with medical equipment and The effects electrical activity sensing pacemakers. It hinders of vibration in medical personnel undertaking fine procedures a helicopter can be minimised (e.g., cannulation, intubation )and simple clinical by securing the assessment (e.g., feeling a pulse). casualty with energy absorbing Noise padding/mattresses, whilst avoiding 2915 Prolonged exposure can cause: direct contact with the airframe. • Headaches, ear discomfort, fatigue, nausea, visual disturbances and vertigo. When travelling in helicopters, casualties and their escort should use earplugs or defenders. • Medical personnel may notice deterioration in their performance of simple tasks. Difficulties in communication can be avoided by the use of headsets or specifically designed flying helmets (NB: equipment alarms may be missed). High levels of noise prevent the use of a stethoscope and hence conventional methods of monitoring cardiorespiratory function. During the flight, the casualty's BP can be estimated by palpating for the presence of a radial, femoral or carotid pulse and assessing CRT (0313). Similarly, respiratory rate, chest expansion and level of consciousness continue to be assessable. Where available, approved, non-invasive ECG, blood pressure and pulse oximetry monitoring, may be used.

Motion sickness 2916 Symptoms tends to occur when visual signals are in conflict with the vestibular evidence of motion, or when signals from the semicircular 623 Chapter_29.qxd 28/09/2004 15:58 Page 624 29: The Incident Response Team and Aeromedical Evacuation

canals do not conform to expected patterns. Even

Hyoscine tolerant individuals will eventually succumb if the (scoplamine) is the motion is intense and of sufficient duration. A number most effective drug of factors are known to worsen or precipitate motion used to combat sickness including: motion sickness. It causes • Anxiety, unexpected movement, low frequency drowsiness, even vibration, sight or smell of food, presence when taken by transdermal route. of nasogastric tube or the vomiting of other casualties. • Clinical factors include: paralytic ileus, pre-existing nausea and gastric distension. Features are general malaise, nausea, vomiting, retching, headache, fatigue and apathy. Casualties are pale, cool to touch and experience excessive sweating (diaphoresis).

Clinical considerations 2917 There are no absolute medical contraindications to evacuation by air. Consideration should be given to what effect the flight may have on the casualty and how these can be minimised. This section gives some broad guidance for the transportation of the more common battlefield injuries, particularly relevant to evacuation by fixed-wing aircraft, but need to be considered during helevacuation.

Abdomen and chest 2918 Gastrointestinal dilatation occurs due to gas expansion at altitude; following abdominal injury, make sure there is a nasogastric tube in place. Ideally, delay emplaning for 10 days after laparotomy or thoracotomy. Following chest injury, insert a chest drain and ensure free drainage (NB: underwater seal is unsafe). Bilateral injury is common and may necessitate a chest drain on the opposite side.

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During early transfer, request that the casualty is flown at sea level cabin pressure. Casualties who have suffered significant thoracic trauma are often transferred whilst sedated, intubated and ventilated.

Head 2919 The casualty should be stable prior to evacuation: • Safeguard the airway, maintain a normal BP and administer high flow oxygen. Casualties who have suffered a significant head injury are often transferred whilst sedated, intubated and ventilated. • Where there is a possibility of spinal injury, the casualty must be fixed to a long spinal board or vacuum mattress. • Significant intracranial haematomas should be evacuated prior to flying. • Transfer requires a medical escort with access to resuscitation equipment. If the casualty deteriorates in flight, do not assume that it is due to the head injury. • Transfer should be direct to a pre-arranged neurosurgical centre. • The casualty should be flown in a head-up position. • Helicopters should ideally remain below 1,000ft (~300m) or, in the case of a fixed wing aircraft fly with a cabin pressure equivalent to sea level.

Musculoskeletal 2920 Fractures require immobilisation prior to transfer. Flying may increase limb swelling leading to a compartment syndrome (0906). This is most likely in the first 10 days after injury/surgery and when a back slab has been converted to a complete 625

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cylinder. Plaster cylinders <3 days old or synthetic It is difficult to assess limb casts <10 days old should be bi-valved (0908) prior circulation and divide to departure. Elevate the limb. Though older casts a cylinder in flight. do not generally need to be divided, plaster shears especially if it made should be available during transfer. of synthetic material. When in doubt, do it before departure. Maxillofacial trauma 2921 The airway is at risk from bleeding, swelling or obstruction. Casualties must have a secure airway prior to transfer (0322). Motion sickness may cause the casualty to vomit in-flight leading to obstruction and aspiration. Transfer requires a trained medical escort with access to resuscitation equipment. Where the jaw is held by intermaxillary fixation (1828), means of releasing the device (e.g., wire cutters) must be at hand.

Ophthalmic trauma 2922 Casualties are managed as in Table 1701. Transfer in a sitting position; no altitude restrictions are required. Following surgery to the eye, the casualty should be transferred in a sitting position and the cabin altitude pressure restricted to 2000ft (~700m).

Working with Aeromed helicopters 2923 Here are some general guidelines: • The "approach" position for a Puma or Sea King is at 2-3 o'clock (nose =12 o'clock), 30m (100ft) away from the helicopter. On receipt of a clear signal from the aircrew (a "thumbs up" by day, one flash of a torch by night), approach the starboard door ("emplaning"). In the case of the Chinook, the approach position is 50m away, between 4-5 o'clock and 7-8 o'clock, travelling towards the rear ramp. • Keep personal belongings and kit to a minimum. 626

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• When not involved in loading or unloading, stay well clear in a position where the crew can see you. • Casualties are loaded feet first and are secured with their heads forward (NB: those with a head injury travelling in Puma or Sea King helicopter are secured feet forward). • If casualties are emplaned whilst the rotor blades are still turning, all loose items must be secured before approaching the aircraft. • Care should be taken when working on sloping or uneven ground. Remember, on an uphill slope the rotor blades will be closer to the ground. • Discuss with the AELO any flying restrictions imposed by the casualty's clinical condition prior to flight • Avoid moving about inside the aircraft and do not touch any controls, especially those painted with black and yellow stripes. • Obey all orders given by the aircrew. Do not leave the aircraft until told to do so.

627

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Practical Procedures

General

3001 This Chapter is intended to 'hold the hand' of the less experienced reader. Other, more specific procedures are presented in the relevant section. There is no substitute for experience. If you are about to do something to a casualty that you have never done before, get someone senior to help. In extremis, consider whether the intervention is really necessary, or if there are safer options. Explain to the casualty what you are about to do and why. If appropriate, obtain informed consent. Wear personal protective clothing - gloves, apron, face mask and eye protection. Make sure all equipment is to hand and is working correctly. Good light, correct positioning, a co-operative casualty and able assistance will make your life much easier.

Airway Manoeuvres

Oropharyngeal airway (OPA) 3002 An OPA (Figure 0309) is sized from the middle of the upper incisor teeth to the angle of the jaw. If it is too large, it may cause gagging; too small and it will be ineffective. A size 2 or 3 Guedel airway (green or yellow) is commonly used in adults: • Inserted concave side uppermost. • On reaching the soft palate, turn the OPA through 180 degrees and slip it into place over the tongue (NB: do not push the tongue back). 629

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Hyoid bone

Thyroid cartilage

Cricothyroid membrane Incision for cricothyroidotomy Cricoid cartilage

Thyroid

Trachea

Fig 3001 Location of cricothyroid membrane. Position of incision for cricothyroidotomy.

Nasopharyngeal airway (NPA) 3003 Select the appropriate width: in the adult male the usual size is an 8 and in females a 7. This approximates to the diameter of the casualty's little finger. Check the length; ideally, the tip should be just visible in the oropharynx. This approximates to the distance from the right nostril to the tragus of the right ear. A NPA can be trimmed to length with scissors. • Insert a safety pin through the flange to prevent inward displacement (Figure 0310). • Lubricate the NPA well. • Most NPAs are designed for insertion through the right nostril. Look for possible sources of obstruction (e.g., fracture, polyp). Stay close to the floor of the nose. Use a gentle rotating motion and aim posteriorly and towards the ipsilateral ear lobe. • If there is resistance, try the other nostril or a smaller-sized NPA.

Needle cricothyroidotomy 3004 This intervention has very limited 630 application on the battlefield. Because they have

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Cricothyroid membrane

Fig 3002 Palpating the cricothyroid 'window'.

a more elastic chest wall, needle cricothyroidotomy may be of greater benefit in children. Equipment • 12 or 14 gauge i.v. cannula. • Oxygen tubing with Y-connector or side hole. • Full oxygen cylinders with flow meter. • 5 ml Syringe. Procedure • Place the casualty supine with the neck in the neutral position. Where indicated, have an assistant immobilise the head and neck. Remove any cervical collar. • Position yourself at the head end of the casualty. Identify the cricothyroid membrane (Figure 3001). This can be felt just below the thyroid cartilage (Figure 3002). Unless contraindicated, identifying the landmarks is facilitated by extending the neck, or by backwards traction on the skin lateral to membrane. This will demonstrate a small depression at the site of the cricothyroid membrane. • Select a 12 or 14 gauge over-a-needle cannula. Attach to a syringe containing a little air. Insert through the skin and cricothyroid membrane into the trachea at 90 degrees with the bevel facing 631 Chapter_30.qxd 28/09/2004 15:58 Page 632 30: Practical Procedures

Thyroid cartilage Cricothyroid membrane Cricoid cartilage Trachea

Fig 3003 Performing a needle cricothyroidotomy.

cephelad (Figure 3003). After perforating the membrane, angle at 45 degrees and advance the cannula at the same time as removing the needle. • Oxygen is insufflated into the lungs under pressure (insufflators are available in operating theatre/ITU). There is a risk of barotrauma (e.g., lung rupture, tension pneumothorax, Figure 0311). • This technique can be performed without an insufflator by attaching the cannula to oxygen running at 15 litres per minute. A Y-connector

Hole cut in oxygen tubing

O2

Plastic cannula

Fig 3004 Needle insufflation. The side hole in the oxygen tubing is 632 intermittently occluded. Chapter_30.qxd 28/09/2004 15:58 Page 633 30: Practical Procedures

Fig 3005 Incising over the cricothyroid membrane.

or side hole is incorporated into the tubing. Occluding the open end of the Y- connector or side hole one second in every five, forces a stream of oxygen into the trachea (Figure 3004). Without an insufflator, this technique will be effective for a maximum of 30-40 minutes in those with normal pulmonary function (i.e., no significant chest injury). A casualty with little or no ventilatory effort will not be adequately oxygenated.

Surgical cricothyroidotomy 3005 Cricothyroidotomy is easy to perform as In general, the cricothyroid membrane lies superficial in the neck cricothyroidotomy and is relatively avascular. Extension of the neck is is avoided if there not essential, this is a "safe" procedure for those is direct laryngeal with suspected cervical spine injury. trauma as this will cause further Equipment disruption. Perform a tracheostomy (The British military pre-packed and sterile instead set contains everything apart from LA, needle and syringe). • Good operating light. • Lignocaine 1% (20 ml).

• Cleaning solution. 633

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Fig 3006 Using the blade handle to open up the incision in the cricothyroid membrane.

• Bag-valve-mask device. • Full oxygen cylinders with flow meter. • Scalpel size 10. • Small artery forceps. • Cuffed tracheostomy tubes size 6·0mm with connector. • Syringes and needles. • Scissors. • Swabs. • Open weave cotton bandage

Procedure • Position and identify the cricothyroid membrane (3003). If not contraindicated, extend the neck and place a sand bag under the shoulders to bring the landmarks into prominence. • Clean the skin. In the conscious casualty, infiltrate with local anaesthetic on either side of the trachea, but not directly over the cricothyroid membrane. 634 Chapter_30.qxd 28/09/2004 15:58 Page 635 30: Practical Procedures

Balloon inflated in trachea

Fig 3007 Inserting a tracheostomy tube through the cricothyroid opening.

• If you are right-handed, approach from the casualty's right side. Stabilise the thyroid cartilage with your left hand. • Make a 2.0-3.0cm transverse skin incision through skin and platysma. Hold the blade perpendicular (Figure 3005). Carefully divide the membrane horizontally. Insert the scalpel handle into the incision and rotate it 90 degrees to open the airway (Figure 3006). A disposable scalpel shaft can be broken in half before making the incision; this removes the risk of self-injury on the blade. Alternatively, use artery forceps or tracheal dilating tongs to open the airway. • Insert a 6 mm cuffed tracheostomy tube (if unavailable, use the smallest available endotracheal tube). Direct the tube distally into the trachea (Figure 3007). Inflate the cuff. The tube should be sutured in position with 2/0 Prolene and/or fixed by tying the bandage attached to the tracheostomy tube flanges securely round the back of the neck. • If spontaneous breathing does not occur, ventilate the casualty. 635

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Complications of cricothyroidotomy and tracheostomy 3006 These include: • Creation of a false passage into the tissues. • Asphyxia. • Laceration of the trachea. • Laceration of the oesophagus. • Haemorrhage or haematoma formation. • Aspiration of blood into the lungs. • Mediastinal emphysema. • Subglottic stenosis/oedema.

Tracheostomy 3007 This is performed either as a planned operation under GA with an endotracheal (ET) tube already in place or as an emergency procedure with local anaesthetic infiltration. Equipment • Lignocaine 1% (20 ml). • Cleaning solution. • Bag-valve-mask device. • Full oxygen cylinders with flow meter. • Scalpel size 10. • Small artery forceps. • Self retaining retractor. • Tracheal dilating tongs. • Cuffed tracheostomy tubes size 8·0 with connector. • Syringe and needle. 636 • Scissors.

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Thyroid cartilage Cricoid Thyroid Incision

Fig 3008 Tracheostomy. Site of incision.

• Open weave cotton bandage. • Swabs. Procedure • Position casualty as for cricothyroidotomy (3005). Palpate the cricoid cartilage and suprasternal (jugular) notch. Make a ~3-7cm horizontal incision midway between the two. (Figure 3008). Divide the platysma and identify the strap muscles. The exposed anterior jugular veins can either be retracted or ligated. • Retract the strap muscles laterally. Identify the thyroid isthmus overlying the second or third tracheal ring. Incise the pretracheal fascia. If necessary, mobilise, divide and transfix the thyroid isthmus (e.g., 2/0 Vicryl).

Platysma First tracheal Strap muscles ring retracted

Thyroid isthmus divided

Incision

Fig 3009 Tracheostomy. Incision over the 2nd and 3rd tracheal rings. 637 Chapter_30.qxd 28/09/2004 15:58 Page 638 30: Practical Procedures

Fig 3010 Inserting the tracheostomy tube.

• Cut a circular window in the trachea (~ 1.5cm in diameter) between the second and third tracheal rings (Fig 3009). • Insert a size 8 cuffed tracheostomy tube (Figure 3010). You may need to use a tracheal dilator. • If the casualty is under GA - the anaesthetist slowly withdraws the endotracheal tube as you advance the tracheostomy tube. • The tube should be sutured in position with 2/0 Prolene or fixed by tying the bandage securely round the back of the neck.

Tracheostomy care. 3008 Meticulous postoperative care will reduce morbidity: • Frequent suction, especially in the first few days. • Prevent crusting by the administration of humidified air. • Delay changing the tracheostomy tube for 5 days to ensure an adequately epithelialised tract.

638 Chapter_30.qxd 28/09/2004 15:58 Page 639 30: Practical Procedures Endotracheal intubation 3009 Endotracheal intubation is only possible in the deeply unconscious casualty (= GCS 4) or following pre-intubation induction of anaesthesia with muscle relaxation. Equipment • Adult endotracheal tubes (ET) size 7.0, 8.0 and 9.0. • 10ml syringe. • Laryngoscope. • Stethoscope. • Lubricant. • Magill's forceps. • Malleable endotracheal introducers. • Oropharyngeal airways (OPA) size 2, 3 and 4. • Bag-valve-mask device. • Suction (e.g., Yankauer sucker). • Scissors. • Open weave cotton bandage. Procedure • Ensure that adequate ventilation and oxygenation are in progress. Check the function of the laryngoscope, suction and the ET tube cuffs. • Position yourself and the casualty as in 3004. Where cervical spine injury is a possibility, avoid neck extension. • During rapid sequence induction of anaesthesia, instruct your assistant to apply cricoid pressure (Sellick's manoeuvre). • Hold the laryngoscope in the left hand and insert the instrument into the right side of the casualty's 639

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Fig 3011 Using the laryngoscope to lift the tongue and epiglottis forward.

mouth, displacing the tongue to the left (Figure 3011). • Look for the epiglottis and place the tip of the blade in the vallecula. Lift the epiglottis forward by pulling, not rotating, the handle of the laryngoscope to visualise the vocal cords (Figure 3012). • Gently insert the ET tube into the trachea without applying pressure on the teeth (Figure 3013). Connect to the bag-valve, inflate the cuff with air (water if aeromed is contemplated) to provide a gas-tight seal and commence ventilation. • Correct positioning of the endotracheal tube is ensured by: • Seeing the tube pass between the vocal cords. • Equal chest expansion. • Air entry in lung bases 640 (auscultate in both axillae). Chapter_30.qxd 28/09/2004 15:58 Page 641 30: Practical Procedures

Lips Epiglottis Tongue Vocal chords

Fig 3012 Visualising the cords during endotracheal intubation.

• Absence of gurgling sounds over It is failure to the stomach. oxygenate the casualty that kills, not inability to • High expiratory levels of CO2 on end-tidal intubate. monitoring (if available). • If you are unable to position the endotracheal tube within 30 seconds, reventilate with a bag-valve-mask device until the casualty is well oxygenated and try again. If in doubt about the position of the endotracheal tube, take it out and oxygenate the casualty by another method. • Release cricoid pressure when correct ET tube placement is confirmed and the cuff is inflated. Fix the tube in position by tying it around the back of the neck with an open weave cotton bandage. Reapply cervical spine immobilisation. Insert an OPA next to the endotracheal tube to act as a bite block and help stabilise the tube's position.

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Fig 3013 Introducing the ET tube through the cords into the trachea.

Complications of orotracheal intubation 3010 These include: • Hypoxia from: • Prolonged attempts to intubate. • Unrecognised oesophageal intubation. • Aspiration of gastric contents. • Damage to the cervical cord in a casualty with an unstable neck fracture. • Pushing the tube too far down (usually into the right main bronchus). The unintubated lung does not get ventilated and eventually collapses. • Leaking endotracheal tube cuff, resulting in loss of seal. • Airway haemorrhage secondary to injury. • Damage to the larynx. • Dental damage caused by levering the laryngoscope blade against the teeth. 642 Loose teeth may be inhaled. Chapter_30.qxd 28/09/2004 15:58 Page 643 30: Practical Procedures

Fig 3014 Application of an Ashermann chest seal.

Breathing Manoeuvres

Application of an Ashermann chest seal 3011 Apply an Ashermann seal in casualties with a penetrating chest wound <12cm in diameter. If the wound is sucking, air will be able to escape from the chest but be prevented from re-entering by the one-way valve during inhalation. Application of the seal must be followed by the insertion of a chest drain. If >12cm, use the opened out wrapper of a field dressing fixed on all four sides plus immediate chest drain insertion. Procedure • Dry the skin using the gauze provided. • Check that the flutter valve is functioning - if in doubt, blow through it. • Expose the adhesive seal. Apply so that the seal completely covers the defect (Figure 3014). • If there are two wounds on the same side, cover one with an impervious dressing or both with an Ashermann seal. 643

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2nd Interspace midclavicular line

Nipple

5th Interspace anterior clavicular line

Fig 3015 Positions on the chest wall for needle thoracocentesis and chest drain insertion. Needle thoracocentesis 3012 This is a potentially life-saving manoeuvre in a casualty with suspected tension pneumothorax (Figure 0311). Procedure • Unless contraindicated (e.g., possible spinal injury), sit the casualty in an upright position (air rises). • Find the second intercostal space (ICS) in the midclavicular line (Figure 3015). One method is to identify the manubriosternal junction (angle of Louis). In most people this is a bony prominence approximately 5cm below the sternal notch adjacent to the second rib. The second ICS lies between the second and third ribs. In practice, because of the overlying muscles, the second ICS is the first easily definable space you come to on feeling down from the clavicle. • Attach a size 12 or 14 over-the-needle cannula to a 5 ml syringe. Fill with a little air. 644

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Fig 3016 Needle thoracocentesis. The over-the-needle cannula is inserted just above the 3rd rib.

• Insert through the skin and direct the needle just over the third rib (Figure 3016). This should reduce the risk of haematoma and intercostal nerve damage. Use a two handed technique. Puncture the parietal pleura (this is usually <2cm from the surface). Aspirate air to confirm the diagnosis (the plunger may be forced out by the high intrapleural pressure). Occasionally, tissue obstructs the cannula and can be released by injecting 1-2 ml of air. • If the diagnosis is correct, advance the plastic cannula and withdraw the needle. An Ashermann seal can be placed over the cannula to stabilise and prevent air being drawn into the chest. A second cannula may improve drainage (NB: a pneumothorax may develop on the opposite side). • You must insert a chest drain during the secondary survey whether or not the diagnosis is confirmed (3013). 645 Chapter_30.qxd 28/09/2004 15:58 Page 646 30: Practical Procedures

Area of infiltration

Fig 3017 Chest drain insertion: site of local infiltration.

Chest tube insertion (thoracocentesis). (The British military pre-packed, sterile set contains everything apart from LA.)

3013 Fluid resuscitation and monitoring of vital signs must be in progress. Equipment • Surgical scrub; sterile drapes and gloves. • 20ml syringe and needle. • Lignocaine 1% (20ml). • Scalpel. • Blunt-nosed forceps. • Chest drainage kit including chest drain (= size 28), tubing and drainage bag with one-way valve (military pattern).

646 Fig 3018 Chest drain insertion: incision over the 5th interspace.

Haemothorax: see Chapter 3 Chapter_30.qxd 28/09/2004 15:58 Page 647 30: Practical Procedures

• Suture material. (e.g. No 1 silk on a hand needle). • Zinc oxide tape. • Gauze swabs. • Scissors. • Dressing. Procedure • Determine the insertion site (Figure 3015). The optimum position is in the fifth intercostal space just behind the anterior axillary line (i.e., just When in doubt, go one space higher. behind the lateral edge of pectoralis major muscle). This is approximately in line with the nipple in the male. Alternatively, count down from the second interspace, or estimate position from the lower border of the casualty's four fingers pressed hard in the axilla. • Position the casualty at 30 degrees. Place pillows, webbing etc. under the shoulder and pelvis. Clean and drape. • Anaesthetise the skin, intercostal muscles and pleura (Figure 3017). • Make a 2.5 cm incision through skin and subcutaneous tissue onto underlying muscle (Figure 3018). Bluntly dissect apart the intercostal muscles using artery forceps (Figure 3019). Work over the top of the sixth rib to minimise damage to the neurovascular bundle. • Puncture the parietal pleura and insert a finger into the incision. Perform a 360 degree finger sweep to clear possible adhesions between lung and chest wall and exclude any herniated abdominal organs (Figure 3020). • If not using the military pattern set, select the largest thoracostomy tube available (ideally >28F). Attach the tube to the drainage bag 647 Chapter_30.qxd 28/09/2004 15:58 Page 648 30: Practical Procedures

Lung

Lung

Pleura

Fig 3019 Chest drain insertion: opening up the intercostal muscles using blunt dissection.

and advance the tube into the pleural space Sometimes the (Figure 3021). Direct it backwards towards flutter valve in the drainage bag the spine and upwards to the top of the thoracic sticks - massage cavity. Signs that you are in the correct place between your fingers are drainage and intermittent fogging of the or inject a little air chest tube during respiratory movements. down the tubing to free it. • Insert the chest drain to a distance of 12-13cm. All the side holes must be well within the chest. Suture the tube in place using a mattress suture and Gibbon's flag (Figure 3022). Apply a dressing and tape the tube to the chest. Check position with a CXR.

Complications of chest tube insertion 3014 These include: • Incorrect tube position inside or outside the chest cavity. 648 Chapter_30.qxd 28/09/2004 15:58 Page 649 30: Practical Procedures

Fig 3020 Chest drain insertion: performing a 360 degree finger sweep.

• Laceration or puncture of intrathoracic or abdominal organs; this can be prevented by the finger sweep before inserting the chest tube. • Damage to the intercostal neurovascular bundle. Effects include local haematoma, haemothorax or intercostal neuritis /neuralgia. • Damage to the internal mammary artery if puncture site is too medial. • Dislodgement of the chest tube or disconnection from the drainage bag. Leaking drainage bag.

Fig 3021 Inserting the chest drain, forceps illustrated; the military chest drain set is provided with a plastic trochar to aid and direct chest tube insertion. 649 Chapter_30.qxd 28/09/2004 15:58 Page 650 30: Practical Procedures

Vertical mattress suture Gibbon’s flag

Loop

Fig 3022 Closing the wound around the chest drain and fixing it in place using a Gibbon's flag 'two knot' technique.

Gibbon’s Flag: • Chest tube kinking or becoming blocked When the chest drain has stopped with blood clot. draining and can be • Infection removed (usually at 48 hours, simply cut (e.g., local cellulitis, thoracic empyema). the loop (Fig 0322) The suture remains • Persistent pneumothorax from large primary in place closing defect; a second chest tube may be required. the wound. • Surgical emphysema (usually at tube site). Mediastinal emphysema.

Circulation Manoeuvres

Needle pericardiocentesis 3015 Clinical features of cardiac tamponade and techniques of drainage are discussed in 0328 and 1542. Despite the diagnosis being correct, clotting of blood within the pericardium, persistent bleeding, iatrogenic myocardial damage and poor operating conditions may all conspire to a poor outcome. Open drainage is increasingly preferred (Figure 3023). Procedure • Check the casualty's vital signs. Where possible, monitor central venous pressure and ECG. • Use a 16 to 18 gauge (minimum length 16cm), over-the-needle catheter, attached to a 20 ml 650 syringe with a three-way stopcock.

Cardiac Tamponade: see Chapters 3 and 15 Chapter_30.qxd 28/09/2004 15:58 Page 651 30: Practical Procedures

A

B

C

Fig 3023 Subxiphoid pericadiocentesis: A) Epigastric incision. B) A plane is developed behind the sternum starting superficial to the posterior rectus sheath. C) The bulging pericardium is picked up between artery forceps and incised.

• Puncture the skin 1-2 cm to the left of the xiphisternum (Figure 3024). • With the needle at a 45 degree angle to the skin, advance the needle aspirating as you go. Aim towards the tip (inferior angle) of the left scapula. • When the needle tip enters the blood-filled pericardial sac, aspirate as much as possible. 651 Chapter_30.qxd 28/09/2004 15:58 Page 652 30: Practical Procedures

Fig 3024 Position of insertion during needle pericardiocentesis. If the needle comes into contact with the ventricular muscle an injury pattern will appear on the ECG monitor: • Extreme ST or T wave changes. • Widened and enlarged QRS complex. • Premature ventricular contractions. Withdraw the needle until the baseline trace reappears. • After aspiration is completed, remove the syringe and attach a three-way stopcock leaving the stopcock closed. Suture the catheter in place and apply a dressing. Should the cardiac tamponade symptoms persist, the stopcock may be opened and the pericardial sac re-aspirated. • Transfer for emergency thoracotomy.

Complications of needle pericardiocentesis 3016 These include: • Aspiration of blood from ventricle. • Laceration of coronary vessels and myocardium. 652

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Long saphenous vein

Incision

Medial malleolus

Fig 3025 Ankle cutdown: position of incision 2cm above and anterior to the medial malleolus.

• Cardiac arrythmia. • Pneumothorax. • Puncture of aorta.

Peripheral venous cutdown 3017 The optimal site for cutdown is over the Avoid cannulating or performing a long saphenous vein approximately 2 cm anterior and cutdown on an 2 cm superior to the medial malleolus (Figure 3025). injured limb. NB: avoid any limb with significant proximal injury. An alternative is the median basilic vein, located 2-5 cm lateral to the medial epicondyle of the humerus in the antecubital fossa. Equipment • i.v. giving set run through with normal saline. • 12 or 14 gauge cannula. • Lignocaine 1% (10ml). • Syringe and needle. • Surgical scrub or alcohol sterets. • Sutures (e.g., 3/0 silk on a cutting needle). • Ties (e.g., 3/0 Vicryl).

• Scalpel (No 22 blade). 653

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A B

C

D E

Fig 3026 Ankle cutdown: A) Incision. B) Pick up fascia over long saphenous vein. C) A 2cm section of vein is mobilised. D) Place stay sutures proximally and distally. Tie the distal stay. E) Make a small venotomy and introduce a cannula; tie the proximal stay over it.

• Two small artry forceps. • Two small retractors. • Gauze swabs (4 x 4 cm). Micropore tape. • Scissors. Procedure • Clean the skin. If appropriate, infiltrate with local anaesthetic. • Make a 2.5 cm transverse incision through the skin and subcutaneous fat (Figure 3026). NB: the vein lies close to the surface. Using blunt dissection, identify the vein and free it from surrounding tissues for a length of 2cm (NB: avoid adjacent saphenous nerve). • Pass proximal and distal ties under the vessel. Ligate the distal tie. Place a clip on both ties 654 for traction. Chapter_30.qxd 28/09/2004 15:58 Page 655 30: Practical Procedures

• Make a small transverse venotomy and gently dilate the opening with the tip of a closed haemostat. Introduce the plastic cannula (without trochar) through the venotomy and secure it in place by tying the proximal ligature. • Attach the giving set and commence flow. Close the incision and apply a sterile dressing. A splint will help secure the line and tubing. Complication 3018 These include: • Haemorrhage or haematoma. • Perforation of the posterior wall of the vein. • Nerve transection. • Phlebitis. • Venous thrombosis.

Femoral vein cannulation 3019 The femoral vein lies medial to the femoral artery (Figure 0702). Remember the mnemonic NAVY - Nerve, Artery, Vein, Y-fronts! Procedure • Set up an i.v. giving set run through with normal saline. Attach a 10 ml syringe onto a 12 or 14 gauge over-a-needle i.v. cannula. Clean the skin. • Identify the femoral artery below the mid inguinal point; the femoral vein lies 1cm medial to the pulsation. • Insert the cannula through the skin. Advance towards the head with the needle at 45 degrees. Apply continuous moderate suction. When the vein is punctured blood will enter the syringe rapidly. Stop, and then gently advance the cannula into the vein while simultaneously withdrawing the needle. 655

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• Suture or tape the cannula into place. Attach the giving set and commence flow. Apply a dressing. • Alternatively, a Seldinger-technique using commercially available femoral vein puncture kits can be employed.

Surgical Handicraft

Wound healing Mechanisms 3020 These are: 1. Primary intention: occurs in clean wounds with direct apposition of the edges. This results is a small, neat scar which epithelialises rapidly. There are three stages in this process: exudation (1-5 days), proliferation (5-21 days) and remodelling (>21 days). 2. Delayed primary intention: This is routinely employed in military wounds where the possibility of infection is high (0502). If after about 5 days the cellular exudate has done its work and the wound looks clean, it may be sutured. The processes of healing are as for primary intention. 3. Secondary intention: An open wound which is too wide to suture will close by a process of wound contraction, granulation of its base and re-epithelialisation from its edges. The end result is a large, distorted scar. The mechanisms are the same as for primary healing but healing is slower with re-epithelialisation occurring at the rate of 1 mm a day. It can be hastened by a partial or full-thickness skin graft.

Factors affecting wound healing 3021 These may be divided into local or 656

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general factors. Methods of optimising healing are listed in 2303. 1. Local • Poor tissue oxygenation and vascularity. • Arterial disease (e.g., atherosclerosis, diabetes, radiotherapy), venous hypertension (e.g., varicose veins), and local pressure (e.g., bedsores). • Sepsis: interferes with granulation tissue formation. • Increased wound tension. This leads to breaking or cutting out of sutures. Causes include: ileus, chronic cough, constipation, urinary obstruction, tumour, ascites, pregnancy and gross obesity. • Poor apposition or movement of wound edges. • Presence of irritants and foreign bodies. • Poor closure technique. 2. General • Age: healing is faster in the young. • Weakened tissues: e.g,. wasting due to nerve damage or cachexia. • Impaired healing: e.g., sepsis, obesity, anaemia, jaundice, malnutrition, hypoproteinaemia, malignant disease, AIDS, steroids, chemotherapy or radiotherapy.

Complications of wound healing 3022 These include: • Wound disruption: may be due to any of the factors in 3021. Disruption of the deeper layers of the abdominal wall with the skin remaining intact results in an incisional hernia. If all layers are affected it is described 657

Skin Graft: see Chapter 23 Chapter_30.qxd 28/09/2004 15:58 Page 658 30: Practical Procedures

as a wound dehiscence ('burst abdomen'). An intestinal anastomotic leak is a serious form of wound disruption. • Cicatrization: causes deformity and loss of function, typically seen after burns. • Keloid scar. • Implantation dermoid. • Colour changes: e.g., skin tattooing due to foreign bodies and dyed suture materials. • Wound pain: may occur due to nerve entrapment.

Principles of wound management 3023 Points include • Wound excision and delayed primary closure see 0503. • The incision must be sufficiently large and extendible to allow for access, but as short as possible and parallel to Langer's lines to ensure optimum healing and a good cosmetic result. Consideration should be given to preserving the local blood supply and avoiding important nerves. To prevent contracture, straight incisions should not be made across joints (Figure 0502). • In an elliptical wound, the length should at least be three times the width, Do not tie the sutures too tight as this will cause oedema and ischaemia of the wound edge. • When closing the abdomen, disruption is less frequent when sufficient length (ideally, more than four to six times that of the wound) of a strong, monofilament suture is used. Transverse incisions heal better than vertical ones. Drains should not be placed through wound.

658 • Sutures are removed when the wound is strong

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enough to support itself. On the face and neck this is usually after 4-5 days, elsewhere after 7-10 days. Leaving sutures in longer than necessary, can cause unsightly cross hatches.

Sutures and ties 3024 These are commonly classified according to: • Source: either natural (e.g., silk) or synthetic (e.g., Dexon, Prolene). • Structure: either monofilament (e.g., Maxon, Prolene) or braided (e.g., silk, Vicyl). • Fate: either absorbable (e.g., Vicryl, PDS) or non-absorbable (e.g., Prolene). Monofilament sutures 'run' easily and are less likely to harbour bacteria, whereas braided sutures tie more securely. Absorbable sutures degrade and consequently do not require to be removed. Some lose their strength relatively quickly (e.g., Vicryl rapide), others more slowly (e.g., Maxon, PDS). They should not be used where long-term approximation is required (e.g., vascular anastomoses). Most non-absorbable sutures retain their strength indefinitely (e.g., polyester, Prolene, stainless steel), a few slowly lose it (e.g., silk, polyamide).

Gauge 3025 The more '0s' on the packet, the finer the suture. Common suture sizes and their uses are shown in Table 3001. Use the smallest gauge for the job. Popular ties (ligatures) are braided absorbable material (e.g., Vicryl or silk). The commonest gauge is 2/0, though heavier or finer ties may be required, depending on the size of the vessels.

Needle

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1/3

2/3

Fig 3027 Correct position of needle in needle holder.

separate tissue fibres and are used to suture hollow viscera (e.g., bowel, common bile duct, blood vessels) and nerves. A blunt needle may sometimes be used to close the abdominal wall (reduces risk of glove puncture) and to suture friable organs (e.g., liver). A cutting needle is used for tough or dense tissue (e.g., skin, ligaments, tendons). Needles may be straight or curved, of varying size and designed for instrument or hand use. When using a needle holder, the needle should be held close to the tips of the instrument and two-thirds of the distance from its point (Figure 3027)

Techniques of wound closure 3027 These include: • The simplest method of closure is an all layers interrupted suture, first picking up one side then the other (Figure 3028). The suture should be relatively square-on to the wound and not invert the skin edge. • For deeper wounds, use two layers or a vertical mattress suture (Figure 3029A). For speed, continuous sutures may be employed (Figure 660 3029 B&C).

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Interrupted sutures

Needle passes deep A B

Take deep bites

C

Skin edges opposed, Skin edges inverted NO! suture not too tight

Blood trapped D in wound E

Fig 3028 Simple wound closure: A) Closure in progress. B) The aim is to insert the needle at 90 degrees to the skin and reach the depths of the wound. C) First pick up one side than the next. If skin edges are close together, it may be possible to do this in one bite. D) tying the knot should result in a square suture. E) avoid inverting the skin and leaving dead splace.

• A technique often appreciated by the casualty is to use an absorbable, subcuticular suture. Bury the knots at each end (Figure 3029D). • Where appropriate, close deep fascia (Figure 3030 A). If there is a significant fat layer, close 661

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A. Vertical mattress sutures

Small bite Large bite B. Continuous suture

C. Blanket stitch

D. Subcuticular

Burried knot

Fig 3029 Other techniques of wound closure A) Vertical mattress suture. A large bite closes the deeper layers and a more superficial bite the skin. B) Simple over-and-over continuous suture. C) Blanket stitch. D) Subcuticular, when using an absorbable suture, bury the knot at both ends.

it with absorbable sutures and bury the knots (Figure 3030 B). • 'Dog ears' can be managed by extending the incision (Figure 3031). • Where appropriate, tendons can be repaired using non-absorbable, monofilament sutures (Figure 3032). Vacular (1020), bowel (1232) 662 and nerve repair (2119) are described elsewhere.

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A

Bury knot

B

Fig 3030 A) Closing deep fascia. B) Closing fat. NB: the knots are buried.

• Knot tying using a needle holder or forceps is illustrated in Figure 3033. For the inexperienced, this is usually quicker and safer than attempting to hand tie.

Fig 3031 Technique for managing a 'dog ear'. 663

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Fig 3032 Technique of tendon repair.

• Alternative wound closure techniques are adhesive strips (e.g., Steristrips™) and wound glue. Staples are increasingly used to close abdominal incisions and to perform bowel anastomoses.

664 Fig 3033 Using an instrument to tie a suture.

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1 Abdominal closure 2/0 Drain attachment 3/0 Bowel anastomoses, fascial repairs 4/0 Routine skin closure 5/0 Vascular anastomoses 6/0 Facial skin closure 9/0 Microvascular anastomoses 10/0 Ophthalmic surgery

Table 3001 Common gauges of suture and their uses.

Drains 3028 Are used to drain or prevent accumulation of body fluids (e.g., pus, blood - see 1230). They can be classified as open or closed, suction or non-suction. Complications of their use include introduction of infection (less likely with a closed system), blockage and damage to adjacent bowel or blood vessels. Rubber drains are occasionally preferred because they stimulate fibrosis. On removal, the surrounding fibrous tract collapses preventing further drainage (e.g., 'T' tube removal after exploration of the common bile duct).

665

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Abbreviated laparotomy - see Drainage 87, 259 Damage Control Surgery Duodenum 292-297 ABCDE 44 Endoscopic Retrograde Abdominal injury Cholangio - Abdominal compartment Pancreatography syndrome 94, 311-312 (ERCP) 299, 303 Abscess 291, 303, 310 Eviscerated bowel 245 Aeromedical evacuation Exteriorisation of colon 624-625 277-278 Anastomotic dehiscence Fluid restriction 245 310-311 Focused Abdominal Antibiotics 137, 256 Sonography for Trauma Aorta 84, 85, 86, 305 (FAST) 249 Assessment, history and Gallbladder 87, 298-299 examination 50-53, General plan for emergency 244-247, 250-252 abdominal surgery Blood supply, small bowel 254-256 and colon 273 Haemorrhage, identification Biliary fistula 87, 291-292 and control 83-90, Biliary tree 87, 88, 90, 256-258 298-299 Hartmann's procedure Casualty positioning after 282-283 injury 245-246 Hepatic artery 307-308 Cholecystectomy 298, Hypotensive resuscitation Cholecystostomy 298-299 68-72, 244, 253-254 Coelic axis 307-308 Ileo-colic anastomosis 279 Colon 271-283 Ileostomy, loop, end and Colostomy 277, 280-282 double-barrelled Complications 310-312 268-270, 280-282 Computerised tomography Ileus 310 (CT) 249-250 Iliac arteries, common, Damage control surgery external, internal 79-94, 254 219- 220, 309 Decompression 246, 295 Incision 256 Diagnostic peritoneal lavage Inferior mesenteric artery 309 (DPL) 248-249 Inferior vena cava 85-88, 89, Diaphragm 283-285 305-307 Double-barrelled stoma Initial management in the 280-282 field 244-246 667 Index.qxd 28/09/2004 15:58 Page 668 Index

Abdominal Injury (cont) Sigmoid colectomy 273 Intestinal obstruction, ileus, Sigmoidoscopy 248 mechanical 310 Small bowel 260-270 Investigations 247-250 Spleen, splenectomy and Jejunal serosal patch 296, septicaemia 283-284 297 Splenic artery 307 Kocher's manoeuvre 292, Stapled anastomosis 265, 294-295 266, 269 Laparoscopy 250 Stomach 285-287 Left gastric artery 307 Stomal problems 311 Left hemicolectomy 273 Superior mesenteric artery Liver 287-292 308 Management at Roles Surgical decision-making 2+ and 3 246-260 250-253 Mucous fistula 270, 280-282 Suspicious features 50, Non-compressible 244-245 haemorrhage Transverse colectomy 273 65-68, 243, 244, 245 Urological injury 327-345 Oesophagus 358-359, Vascular exposure 305-309 381-384 Wound closure 90-91, Operative considerations 259-260 253-260 Wound dehiscence 310 Organ damage, systematic Wound dressings 245 search 83, 84, 258-259 Above knee amputation (AKA) Packaging for transfer 245, 238-239 246 Acceleration/deceleration, Pancreas 299-303 aeromedical evacuation 622 Pathophysiology 243-244, Acetabular fracture 318 253-254 Acetazolamide 425 Portal vein 308 Acute psychiatric disorders (APD) Radiological investigations 593 248, 299 Acute psychological disorders Rectal injury 275, 282-283 601-603 Resuscitative laparotomy 68, Acute psychological reactions to 80-87, 246 combat 593-595 Retroperitoneal haemorrhage, Acute stress reactions (ASR) 593, management of 303-309 596-598 Right hemicolectomy 273 Acute tubular necrosis, 'Second look' laparotomy 261 prevention of 519, 522 Secondary haemorrhage 310 Adrenaline 125, 576 668 Index.qxd 28/09/2004 15:58 Page 669 Index

Adult respiratory distress Air Evacuation Liaison Officer syndrome 354 (AELO) 620 Advanced Trauma Life Support Air sinuses 448, 451 (ATLS) 606 Airway and cervical spine control Advancement flap 534, 535 45-48, 55-61 Aeromedical evacuation Airway assessment Abdomen and chest 624-625 - talk, look, listen and Acceleration/deceleration 622 feel 45 Aeromedical Evacuation Airway management 55-61, Squadron 619 555-556 Air Evacuation Co-ordination Airway obstruction Officer (AECO) 620 preventable deaths 46 Air Evacuation Liaison Anaesthetic technique Officer (AELO) 620 557-567 Altitude 621 Aspiration, reducing risk Categorisation 619, 621 556, 559 Clinical considerations Bag-valve-mask 64 624-626 Breath sounds 49 Critical Care Air Support Cervical collar 55, 56 Teams (CCAST) 620 Cervical spine control 55 Head injury 416, 625 Cervical spine injury Maxillofacial trauma 626 - suspicious features Motion sickness 624 47, 48 Musculoskeletal trauma Chin lift 57 625-626 Clearing the airway 57-58 Noise 623 Combitube 61 Ophthalmic injury 429-430, Cricothyroidotomy 59, 626 630-636 Potential in-flight problems Endotracheal intubation 59, 620 639-642 Strategic evacuation 619 Facial fracture, causing Tactical evacuation 620 airway obstruction Temperature 621-622 45-47, 57 Vibration 622-623 Finger sweep 57 Working with Aeromedical Helmet removal 54, 55 helicopters 626-627 Inappropriate/ Aetiology of injury - see Patterns incomprehensible of Injury in Military Operations speech 45 Air Evacuation Co-ordination Inhalational injury 47, Officer (AECO) 620 503-504, 509-510 669 Index.qxd 28/09/2004 15:58 Page 670 Index

Airway control (cont) Alcohol, in cold injury 589 Injuries associated with Alfentanil 558, 559, 561, 563-564, airway obstruction 46 571 Jaw thrust 57 Altered level of consciousness 45 Laryngeal injury 48 AVPU 53, 393-394 Laryngeal mask airway GCS 395-397 (LMA) 61 Pupil assessment 53, 394 Log roll 74 Altitude, Aeromedical evacuation Maintaining the airway 58-59 621 Mouth to mask ventilation 64 Amethocaine 425 Mouth to mouth/mouth to Amitriptyline 590 nose ventilation 64 Amoebic dysentery Nasopharyngeal airway Clinical features 550-551 (NPA) 58, 630 Diagnosis 549-550 Neck examination 48 Differential diagnosis 550 Neck injury/wounds 45,47,48 Diloxanide furoate 551 Needle cricothyroidotomy Entamoeba histolytica 549 61, 630-633 Metronidazole 551 Nerve agent poisoning Pathophysiology 549 34-37,45, 46 Tinidazole 551 Oropharyngeal airway (OPA) Treatment 551 58, 59, 629 Amputation 100 Oxygen administration 55, Above knee amputation 565 (AKA) 238-239 Protecting the airway at risk Ankle 241-242 59-61, 555-556, 633-642 Antibiotics 137 Secure airway - indications Arterial injury leading to 229 59-60 Assessment for possible Suction to clear mouth 57 amputation 96, 227 Surgical airway 59-61, 556, Below knee amputation 633-638 (BKA) 240 Three point cervical spine Casualty transfer 234-235 control 55, 77 Damage control surgery 80 Three-quarters prone Definitive/final amputation position 58 229, 236-237 Total airway obstruction 45 Delayed primary closure Tracheal displacement 48, 63 104-105, 229, 235-236 Tracheostomy 59, 470, Entrapment leading to 230, 636-638 232 Triage 107-112 Foot 242 670 Index.qxd 28/09/2004 15:58 Page 671 Index

Frequency of traumatic Alfentanil 558, 559, 561, amputation 227 563-564 General principles 227-229 Anaesthetic drugs 558 Indications 229-231 Anaesthetic technique Infection leading to 230 557-567 Knee disarticulation 239 Analgesia 117-119, 557, Knee joint, retaining the 558, 559 231-232 Aspiration, reducing risk Level of amputation 231-232 556, 559 Mangled Extremity Severity Atropine 561 Score (MESS) 229-230 Balanced anaesthesia Mine injury 227, 228 557-562 Myoplastic repair 229, 235-236 Balanced anaesthesia, Multiple injuries leading to 231 non- emergency cases Operative technique in 562 emergency amputation Breathing 556 232-233 Circulation 557 Pathophysiology 227 CompPAC ventilator 566-567 Preventing skin/muscle Cricoid pressure 556, 559 retraction 233 Environment for safe Radical wound excision 100 anaesthesia 553-554 Rehabilitation 242 Epidural 126, 564 Revision 242 Equipment 565-567 Second look wound excision Etomidate 559, 560 229 Fentanyl 558, 559, 561 Severity of injury leading to Field Hospital (Role 3) 554 229-230 Field Surgical Team (Role 2) Skin coverage 236-237 554 Splinting the stump 234 Glycopyrolate 561 Stump dressing/bandage Incident Response Team 233-234, 236 (IRT) 554, 615-619 Syme 241 Induction of anaesthesia Tourniquet, use leading to 558, 559-560 231 Isoflurane 558, 560, 561, 566 Upper limb 237 Ketamine 558, 559, 560, 562 Wound excision 97-101, 232, Local analgesia 124-128, Amoxicillin 463 558, 565 Anaesthesia in the field Maintenance of anaesthesia Aims 553 560-561 Airway 555-556 Midazolam 558, 563 671 Index.qxd 28/09/2004 15:58 Page 672 Index

Anaesthesia in the field (cont) Surgical airway 556, 633-638 Modular Transportable Suxamethonium 558, 560, 563 Surgical Facility (MTSF) "Thermopols" 565 553 Thiopentone 558, 559, 560 Monitoring equipment 566 Total Intravenous Morphine 557, 558, 559, 561 Anaesthesia (TIVA) Muscle relaxation 558 562-564 NBC filter 567 Transfer from the operating Neostigmine 561 theatre 561 Nitrous oxide 560 Tri-Service Anaesthetic Oxford Miniature Vaporiser Apparatus (TSAA) 557, (OMV) 566, 567 566 Oxygen 565 Types of anaesthesia 553, 554 Oxygen concentrators 565 Types of casualty 555 Pancuronium 558 Vecuronium 558, 560-561, 563 Patient Controlled Analgesia Ventilation 64-65, 560 (PCA) 561 Analgesia 63, 115-130, 557, 558, Penetrating neck injuries 48, 559 556 Analgesic protocol 117 Premedication 118-119, Antiemetics 119 392-393, 556, 557, Approach to pain relief Preoperative assessment 116-117 555-557 Assessment of pain 116-117 Preoxygenation 559 'Balanced analgesia' 124 Propofol 558, 559, 560, Bupivicaine 125-126 563-564 Burns 507, 509, 515, 520 Rapid sequence induction Catheterisation 126 556, 559 Chest injury 129 Refrigeration 565 Codeine phosphate 123 Regional anaesthesia Cold injury 589, 590 564-565 Compound analgesic Reversal of anaesthesia 561 preparations 123 Resuscitation 557, 559 Cyclizine 119 Roles 554 Dextropropoxyphene 123 Sanders Oxygen 'T' 566, 567 Diclofenac 123-124 Sleep, induction and Dihydrocodeine 123 maintenance 558 Effects of inadequate pain Spinal anaesthesia 126, 564 control 115-116 Suggested balanced Entonox 121-123 anaesthetic technique Entonox and chest injury 129 672 559-562 Entonox and head injury 129 Index.qxd 28/09/2004 15:58 Page 673 Index

Epidural analgesia 126, 564 Severe pain - management Eye injuries 126, 425 118-123 Factors affecting choice of Spinal analgesia 126, 564 analgesia 117-118 Topical analgesia 126 Femoral nerve block 126-127 Anastomosis Haematoma block 126 Colon 274-280 Head injury 128-129, 392 Dehiscence, bowel 310-311 Hyoscine 119 Small bowel 263-269 Ibuprofen 117, 123-124 Vascular 201-211 Inadequate pain relief Angiography, completion, - possible causes 116 on-table 198, 199, 204 Intercostal nerve block Ankle brachial pressure index 126-127 (ABPI) 198 Ketamine hydrochloride Anteroposterior compression 120-121 (APC) fracture types 1-3 Ketorolac 123-124 315-317 Lignocaine (Lidocaine) Anterior nasal packing 467-468 125-126 Anthrax 144-145 Local analgesia 124-128, Antibiotics 132-146 558, 565 Battlefield considerations 137 Mass casualties 129-130 Benzyl penicillin 137, 521 Maximum safe dose (MSD) Burns 510, 521 of local analgesia 125-126 Ceftriaxone (Rocephin) Medimech Auto Injector 118 137-138, 425, 521 Metoclopramide 119 Cefuroxime (Zinacef) 139 Mild to moderate pain Choice of antibiotics 137-139 - management 123-124 Ciprofloxacin (Ciproxin) Monitoring of effect 116-117 138-139 Morphine sulphate 118-120 Clarithromycin (Klaricid) Naloxone 119-120 138-139 Non-steroidal anti-inflammatory Co-amoxyclav (Augmentin) drugs (NSAIDs) 123-124 137-138, 463, 466 Ondansetron 119 Doxycycline 145 Paracetamol 124 Ear 462-463 Patient Controlled Analgesia Eye 424, 425 (PCA) 119 Flucloxacillin 139, 521 Perception of pain 115 "Gas gangrene" 141` Pleural anaesthesia 127 Gentamicin 521 Principles of management 115 Gut or other hollow viscus Prochlorperazine 119 wounds 137 Head injury - open 138, 392 673 Index.qxd 28/09/2004 15:58 Page 674 Index

Antibiotics (cont) Arteriography, on-table, Hospital acquired infection completion 198, 199, 204 138 Artery - see also Vascular Injury Laboratory support to identify Anterior tibial 224, 225 sensitivity 135-136 Aorta and great vessels 84, Limb injury 137 85, 86, 305, 357, 374-376 Lower respiratory tract Axillary 216-217 infection 138 Brachial 217 Methicillin-resistant Brachiocephalic 212-213 Staphylococcus aureus Carotid 89, 212-214 (MRSA) 136 Coeliac axis 307 Metronidazole (Flagyl) Common iliac 219, 309 137-138 Crural vessels 224-226 Necrotizing fasciitis 142-143 External iliac 219-220, 309 Penicillin allergy 139 Femoral 89, 220-221 Principles of treatment 136 Hepatic 89, 307 Prophylaxis 132 Inferior mesenteric 309 Resistance - identification of Internal iliac 313, 309 136 Left gastric 307 Soft tissue and muscle injuries Middle meningeal 407, 408, 413 137 Peroneal 225-226 Tetanus 140 Popliteal 222-223 Trimethoprim 138 Posterior tibial 224, 225 Urinary tract infection 138 Profunda femoris 220-221 Wound infection 138-139 Radial 218-219 Anticonvulsants 392-393 Renal 332-333 Antiemetic Splenic 307 Cyclizine 119 Subclavian 212-213, 215-216 Hyoscine 119 Superior gluteal 313 Metoclopramide 119 Superior mesenteric 308 Ondansetron 119 Ulnar 218-219 Prochlorperazine 119 Vertebral 215 Antipersonnel mine injury 100 Ashermann chest seal 62, 359, 643 Aorta and great vessels 84, 85, ATOMIC -life-threatening chest 86, 305, 357, 374-376 injuries 49 Aortography 363 Atrium 372, 373 Arachnoid mater 385-386 Atropine 35-36 Arch bar 453 Anaesthesia, use in 561 Arsenical blister agents 39-41 Heat illness 36-37, 582 Arterial line, indications and Ophthalmic preparation 425 674 technique 572-573 Poisoning 36-37 Index.qxd 28/09/2004 15:58 Page 675 Index

Avizafone 35 Sensitivity 135-136 AVPU assessment of conscious Staphylococcus aureus 134, level 53, 389, 393-394 137, 138, 520-521, 546, Axial flap 537-538 547 Axillo-femoral bypass graft 210-211 Streptococcus pneumoniae Axonotmesis 484-485 138 Azithromycin 425 Streptococcus pyogenes 134, 136, 137, 138, Back bleeding after vascular 520-521, 547 surgery 201-202 Yersinia pestis 145-146 Bacteria Bag-valve-mask 64 Aerobic organisms 134 135, Bail-out surgery - see Damage 138, 142 Control Surgery Anaerobic organisms 134 'Balanced anaesthesia' 557-562 135, 137, 138, 142 'Balanced analgesia' 124 Antibiotics 132-146 Ballistic injury 11-23 Bacillus anthracis 144 Available energy 12 Bacillus cereus 134 Cavity shape 17-18 Bacteroides fragilis 135 Cavity size 16-17 Clostridium botulinum 146 Change in presented area of Clostridium perfringens 134, a missile 20 141, 142 Classification 12-15 Clostridium septicum 134 Clinical consequences 11, Clostridium species 134 19-22 Clostridium tetani 134, 140 Compounding factors Colonisation, definition 133 20-23 Escherichia coli 135, 138 Contamination 18-19 Gram-staining 145, 146 Effect of tissue properties on Identification 135-136 injury pattern 19-21 Infection, definition 133 Energy transfer 12, 15-23 Klebsiella species 135, 136 High energy-transfer wounds Methicillin-resistant 12-13 Staphylococcus aureus Low energy-transfer wounds (MRSA) 136 12 Multi-drug resistant Mechanical or functional Klebsiella species 136 injury 15 Peptococcus species 134 Mine injury 227 Peptostreptococcus species Fragmentation of missile 13, 134 16, 21, 22 Proteus species 135 Secondary fragments 13, 21 Resistance 136, 137, 138 Stress (pressure) wave 15-16 675 Index.qxd 28/09/2004 15:58 Page 676 Index

Ballistic Injury (cont) Breathing and ventilation Pathophysiology 11-23 - decision making 61 Temporary cavity 16-23 Breathing assessment Vascular injury 194 - inspect, feel, percuss Wound track length 22 and auscultate 48-49 Yaw 17-18, 21, 23 Capillary refill time (CRT) 53 Balloon catheter to control Cardiac tamponade 64, 358, haemorrhage 66, 86- 88, 371-373, 650-651 290, 306 Causes of hypovolaemic Basal skull fracture 414-415 shock 50, 52 Battlefield Advanced Trauma Life Cervical collar 55, 56 Support (BATLS) 43-78, 95 Cervical spine control 55, 77, ABCDE 44 479 Abdominal injury, suspicious Cervical spine injury features 50 - suspicious features 47 Abnormal breath sounds 45 Chest drain (thoracocentesis) Airway and cervical spine 62-63, 646-650 control 45-48, 55-61 Chest injury - suspicious Airway assessment - talk, features 48-49 look, listen and feel 45 Chin lift 57 Airway management 55-61 Circulation with haemorrhage Airway obstruction control 50-53, 65-73 - preventable deaths 46 Clearing the airway 57-58 Altered level of consciousness Clotting adjuncts 67, 85, 199 45 Colloid infusion 68 Analgesia 63, 116-118 Combitube 61 Ashermann seal 62, 643 Compressible haemorrhage 65 ATOMIC 49 Cricothyroidotomy 59, 630-636 AVPU assessment of Crookham halter 68, 72 conscious level 53, 394 Crystalloid infusion 70 Bag-valve-mask 64 Cyanide poisoning 45 Balloon catheter to control Definitive care 44, 76 haemorrhage 66 Disability/neurological status "Blood on the floor and four 53 more" 50 Dullness to percussion 49, 51 Blood transfusion 70, 519, Endotracheal intubation 59, 612-613 639-642 Breath sounds 49 Estimating blood pressure Breathing and ventilation from pulses 53 48-50, 61-65 Exposure 53 676 Index.qxd 28/09/2004 15:58 Page 677 Index

Facial fracture causing airway Limb elevation 67-69 obstruction 45-47, 57, Log roll 74 451, 452 Long bone fractures Femoral vein cannulation 68, - suspicious features 50 653-655 Long saphenous vein cut Finger sweep 57 down 68, 653-655 Flail chest 63, 349, 350 Lung contusion 49, 353-354 Fluid resuscitation algorithm 72 Maintaining the airway 58-59 Haemorrhage control 66, Massive haemothorax 62, 83-90, 256-258, 376 352-353, 646-650 Haemothorax 62, 352-353, Mental state in hypovolaemic 646-650 shock MIST 44 Helmet removal 54, 55 Monitoring resuscitation 73 Hoarseness 45 Mouth to mask ventilation 64 Hyper-resonance 49, 51 Mouth to mouth/mouth to Hypertonic saline dextran nose ventilation 64 (HSD) 72 Nasopharyngeal airway (NPA) Hypotensive resuscitation 58, 630 68-72 Neck examination 48 Hypovolaemic shock 50-53 Neck injury/wounds 45, 47, Immobilisation of fractures 48, 470-473, 556 and soft tissue injuries Neck wound - application of 67-69, 156-161 a pressure dressing 66 Inappropriate/ Needle cricothyroidotomy incomprehensible 61, 630-633 speech 45 Needle pericardiocentesis Inhalational burns 6, 47, 64, 650-653 503-504, 514-515 Needle thoracocentesis 62, Injuries associated with 644-645 airway obstruction 46 Nerve agent poisoning 34-37, Intercostal nerve blocks 63, 45, 46 126-128 Non-compressible Intra-osseous infusion 68 haemorrhage 65 Intraperitoneal haemorrhage, Open pericardiocentesis 64, methods of assessment 371-373, 650-651 75, 245-250 Open pneumothorax 62, Intravenous fluids 70-72 351-352, 643 Jaw thrust 57 Oropharyngeal airway (OPA) Laryngeal injury 48 58, 629 Laryngeal mask airway Oxygen administration 55, 565 (LMA) 61 Packaging 76 677 Index.qxd 28/09/2004 15:58 Page 678 Index

BATLS (cont) Tension pneumothorax Pelvic fracture 68, 74, 62- 63, 351, 644-646 313-318 Thomas splint 68, 72 Pelvis/retroperitoneal injury Thoracocentesis 62-63, - suspicious features 50 646-650 Penetrating neck wounds Three point cervical spine 48, 470-473, 556 control 55, 77 Phases of management 44 Three-quarters prone Pressure points for position 58 haemorrhage control 66 Total airway obstruction 45 Primary survey 44 Tourniquet 66-67, 97, 99, Protecting the airway at risk 151, 195, 231, 232-233 59-61, 633-642 Tracheal displacement 48, 63 Pulse rate 53 Traction splint 67, 71 Pupil assessment 53, 349, Tracheostomy 59, 470, 422, 431 636-638 Resuscitation 44, 55 Triage 107-112 Rib fractures 49, 348-349 TWELVE 48 Sagar splint 67, 71 Venous cannulation 68, Scene safety 44 655-656 Secondary survey and Venous cut down 68, 653-655 packaging 44, 74-76 Venous distension 48 Secure airway - indications Ventilatory support 63-65, 59-60 571-572 Sources of major blood loss Wound dressing 66, 95 50 X-rays after polytrauma 75 Signs of respiratory distress Battle's sign 414-415 48-49 Below knee amputation (BKA) 240 Slings 69 Benoxinate 425 Splint aluminium malleable Benzyl penicillin - see Penicillin (SAM) 67, 70 Biliary Splinting fractures and soft Fistula 87, 291-292 tissue injuries 67-69, Tree 87, 88, 90, 298-299 156-161, 163-180 Biological agent/warfare/weapons Sucking chest wound 62, 144-149 351-352, 643 Actions to be taken 149 Suction to clear mouth 57 Anthrax 144-145 Surgical airway 59-61, 508, Battlefield considerations 556, 633-638 147-149 Surgical emphysema 48 Botulism 146 678 Index.qxd 28/09/2004 15:58 Page 679 Index

Definition 144 Eyes, effect on 40-41, 435, 523 Grouping of agents 144 Lewisite 39-40, 524 Impact on field surgery 148 Treatment 39-41, 524-525 Plague 145-146 Nitrogen mustard 39-40 Ricin 132,144 Pathophysiology 39 Smallpox 146 Respiratory effects 41 Strategy 147 Skin, effect on 40 Target 147 Sulphur mustard 39-40 Bismuth iodoform paraffin ribbon "Blood on the floor and four more" gauze (BIPP) pack 467 50 Bladder injury 340-342 Blood transfusion 70, 519, 612-613 Aetiology 340 Blood pressure, estimation from Clinical features 340-341 peripheral pulses 53 Investigation 341 Blunt injury 3, 6, 11 Management 341-342 Abdomen 244 Open cystotomy 344-345 Head 386-387, 405-416 Pathophysiology 340-341 Kidney 327 Repair 341-342 Maxillofacial 441 Suprapubic catheter insertion Neck 469-470 344-345 Nuclear 30 Blast injury 6, 23-27 Spine 476, 480 Abdomen 6, 244 Vascular trauma 194 Acoustic coupling 26-27 Boari flap 338, 339 Blast lung 6, 354-355 "Bogota bag" 91 Blast protection 27 Botulism/botulinum toxin 146 Bowel injury 6, 244 Brachial plexus 486-488, 499 Confined space 6 Brain injury - see Head Injury Ear 463 Breath sounds 45 Mechanism of primary 25-27 Breathing and ventilation 48-50, Mine injury 227 61-65 Nuclear 29-30 Anaesthesia 556 Patterns of injury 27 Ashermann chest seal 62, 643 Vascular injury 24, 26-27 Assessment - inspect, feel, Under water 6 percuss and auscultate Blindness - see Ophthalmic Injury 48-49 Blister (vesicant) agents ATOMIC 49 Arsenical blister agents 39-40 Auscultation 49 Clinical features 39-41 Breath sounds 45 Detection 32-33, 39-40 Burns 47, 503-504, 507-508, Dimercaprol (British 514-515 Anti- Lewisite BAL) 40 679 Index.qxd 28/09/2004 15:58 Page 680 Index

Breathing and ventilation (cont) British Anti-Lewisite (BAL) 40 Chest drain (thoracocentesis) Bupivicaine 125-126 62-63, 646-650 Burns Chest injury - suspicious Acute tubular necrosis, features 48-49 prevention of 162, 519, 522 Cyanide poisoning 45,46 Analgesia 117-119, 507, 509, Decision making 61 515, 520 Dullness to percussion 49, 51 Antibiotics 137, 510, 521 Flail chest 63, 349, 350 Airway 503, 507-508 Haemothorax 62, 352-353, Benzyl penicillin 521 646-650 Blood transfusion 519 Hyper-resonant percussion Carbon monoxide 504 note 49, 51 Carboxyhaemoglobin 503, 504 Inhalational burns 47, 503 Ceftriaxone 137, 138, 521 504, 507-508, 514-515 Chemical burns 39-41, 506, 523 Intercostal nerve block 63, Circulation 509, 510-513 126-128 Cling film 506 Lung contusion 49, 353-355 Combined with penetrating Massive haemothorax 62, injury 6 352-353, 646-650 Compartment syndrome Needle thoracocentesis 62, 154-156, 522 644-645 Cooling 506 Nerve agent poisoning 34-37, 1% Copper sulphate 524 45, 46 Cutaneous injury 504-506 Open pneumothorax 62, Cyanide 504 351-352, 643 Deep dermal burns 504-505 Percussion note 49, 51 Dexamethasone 508 Rib fracturs 49, 348-349 Dressings 506-507, 513, Signs of respiratory distress 518-519, 520 48-49 Electrical burns 521-523 Sucking chest wound 62, Epidemiology 501-502 351-352, 643 Epidermal burns 504, 505 Surgical emphysema 48, 352 Eschar/escharotomy 508, 516, Tension pneumothorax 62, 517-518 63, 351, 644-646 Estimating burn size 507, 509, Thoracocentesis 62-63, 510, 515-516 646-650 Exposure/environment 509 Tracheal displacement 48, 63 Fasciotomy 156 Triage 107-112 Feeding 520, 526 Ventilatory support 63-65, First aid 506-507 680 571-572 Flammacerium cream 518-519 Index.qxd 28/09/2004 15:58 Page 681 Index

Flammazine 518-519 136-138, 520-521 Flucloxacillin 521 Surgery 517-518 Fluid requirement 510-513, Surgical airway 59-61, 508, 515, 519-520 556, 633-638 Full thickness burns 505 Systemic Inflammatory Gentamicin 521 Response Syndrome Hand burns, management of (SIRS) 503, 525 519 Systemic injury 502-503, Hypovolaemic shock 509, 504, 521 510-513 Tank crews, in 6 Incidence 6, 501-502 Total body surface area Infection 520-521 burned (%TBSAB) Inhalational injury 6 47, 502-503, 510, 511, 503-504, 514-515 515-516, 525, 526 Lund and Browder chart Triage for transfer 507, 513, 525 515, 516 Vesicant burns 39-40, 435, 524 Lung injury 503, 508 Burr holes 408-411 Management 506-526 Bypass procedures, restoration Management at Role 1 and of blood supply 210-211 Role 2 507-513 Management Role 3 513-525 Cable graft 496 Mass casualty scenarios 525 Capillary refill time (CRT) 53 Monitoring 512-513, 514, Carbon monoxide poisoning 504 519-520 Carboxyhaemoglobin 503, 504 Moyer's solution 526 Cardiac injury 357-358, 371-375 Nuclear explosion 29-30 Aorta and great vessels Nursing 519-520 357, 374-376 Nutrition 520, 526 Atrium 372, 373 Ophthalmic burns 39-40, Beck's triad 64 428, 435, 523 Cardiac enzymes 363 Palmar surface, to estimate Cardiac laceration 373-374, 375 burn size 510 Cardiac tamponade 64, 358, Partial thickness burns 504 371-373, 650-653 Pathophysiology 6, 502-506 Coronary artery injury and Phosphorus burns 523-524 occlusion 358 'Rule of Nines' 510, 511 Internal cardiac massage 371 Serial halving to estimate Myocardial contusion 357-358 burn size 507 Needle pericardiocentesis Staphylococcal infections 64, 650-653 134, 137, 138, 520-521 Open pericardiocentesis 64, Streptococcal infection 134, 371-373, 650-651 681 Index.qxd 28/09/2004 15:58 Page 682 Index

Cardiac injury (cont). Cerebral perfusion pressure 387 Valvular disruption 358 Cerebrospinal fluid (CSF) 386 Ventricle 373-374 Cervical spine - see Neck Injury Cardiopulmonary resuscitation Cervical collar 55, 56 (CPR), cold injury 585 Injury - suspicious features Cardiovascular support, 47-48 indications and methods Manual stabilisation 55 572-576 Radiology 469 Cartella shield 428 Spinal board/vacuum mattress Cartilage 101 76-77, 478-479, 618 Casualty Protection Equipment Three point fixation 55 (CPE) 34 Chemical agents 31-42 Casualty template, in war fighting 1 Arsenical blister agents Casualty transfer chain - see 39-41, 506, 523 Aeromedical Evacuation Assessment of scene and Aeromedical Evacuation casualties 31-32 Squadron 619 Atropine 35-36 Air Evacuation Co-ordination Atropine poisoning 36-37 Officer (AECO) 620 Avizafone 35 Air Evacuation Liaison Blister (vesicant) agents Officer (AELO) 620 39-41, 506, 523 Close Support Medical Casualty Protection Regiments (113) Equipment (CPE) 34 Critical Care Air Support Chemical Agent Monitor Teams (CCAST) 620 (CAM) 32-33 Echelons of Medical Care Chlorine 41-42 (First -Fourth Line) 112 Classification 31 Field Hospital 112 Combopen 35 Medical Section 112 Contaminated wounds 34, 97 Primary Casualty Receiving Cyanide 37-38 Ship (PCRS) 113 Decontamination 33-34 Regimental Aid Post (RAP) Detection 32-33 112 Diazepam 35-37 Roles of Medical Care Eye injury 420, 435-436 (Roles 1-4) 112 Formulation and delivery 31 Unit Aid Post 112 Fuller's earth 33 Ceftriaxone (Rocephin) 137-138, GA (Tabun) 34 425, 521 GB (Sarin) 34 Cefuroxime (Zinecef) 139 GD (Soman) 34 Central venous line, indications 0.5% Hyperchlorite solution 33 682 and technique 573-575 Index.qxd 28/09/2004 15:58 Page 683 Index

Individual Protection Chloramphenicol, use after eye Equipment (IPE) 32 injury 425 Man Portable Chemical Agent Chlorine poisoning 41-42 Detector (MCAD) 33 Cholecystectomy 298 NBC suits 32 Cholecystostomy 298-299 Nerve Agent Inhibited Ciprofloxacin (Ciproxin) 138, 139, Enzyme and Alarm 425 Detector (NAIAD) 33 Circulation with haemorrhage Nerve Agent Pretreatment Set control 50-53, 65-73 (NAPS) 35 Abdominal bleeding Nerve agents 34-37 - identifying the source Nitrogen mustards 39-41 83, 256-259 Oedemagens 41-42 Abdominal bleeding One colour detector paper - suspicious features 32-33 50, 247-250 Ophthalmic injury 420, Abdominal visceral injury 435-436 - damage control 79, 87, Phosgene 41-42 88, 254-258, 283, Pralidoxime 35, 36 289- 290 Pretreatment 35 Amputation 80, 229-233 Protection 32 Anaesthesia, maintaining Pyridostigmine 35 during 557 'Quick look' 45-46 Aortic clamping 84-86, 305, 373 Residual Vapour Detector Autotransfusion 82 (RVD) Balloon catheter to control Sulphur mustards 39-41 haemorrhage 66, 86-88 Three colour detector paper 290, 306 32-33 Blood transfusion 70, 82, 519, Vesicant burns 39-41, 506, 612-613 523 Capillary refill time (CRT) 53 VX nerve agent 34 Cardiac tamponade 64, 358, Wounds in a chemical 371-373, 650-651 environment 97 Cardiovascular support, Chemosis, eye 429 intensive care 572-576 Chest drain (thoracocentesis) Causes of hypovolaemic 62-63, 360, 646-650 shock 50, 52 Chest injury - see Breathing and Chest injury - suspicious ventilation, Thoracic injury features 48-49 Chest X-ray, assessment of 362 Chest wounds - controlling Chilblains 587 haemorrhage 87, Chin lift 57 376-379 683 Index.qxd 28/09/2004 15:58 Page 684 Index

Circulation (cont) Liver injury 85-87, 353-356, Clotting adjuncts 67, 85, 199, 376-381 288 Long bone fracture Coagulopathy 80 - suspicious features 50 Colloid infusion 68 Long saphenous vein cut down Compressible haemorrhage 68, 653-655 65 Lung injury 87, 353-356, Critical limb ischaemia 89 376-381 Crystalloid infusion 70 Lung rotation to control Embolisation 90 haemorrhage 87 Estimating blood pressure Massive haemothorax 62, from peripheral pulses 53 352-353, 646-650 Femoral vein cannulation 68, Mental state in hypovolaemic 653-655 shock 51 Fluid resuscitation algorithm Monitoring resuscitation 73 72 Neck veins 48 Haemorrhage control 66-68, Neck wound, application of a 83-90, 256-258, 376 pressure dressing 66 Haemostasis - damage Needle pericardiocentesis control surgery 79, 85-87 64, 650-653 Haemothorax 62, 352-353, Non-compressible 646-650 haemorrhage 65 Hilar clamping to control Open pericardiocentesis 64, haemorrhage 87, 376 371-373, 650-651 Hypotensive resuscitation Packing for haemorrhage 68-72 control 83, 85, 93, 289, Hypovolaemic shock 50-53, 300, 303-304, 467-468 80 Pelvic fracture 68, 74, 313-326 Immobilisation of fractures Pelvis/retroperitoneal injury and soft tissue injuries - suspicious features 50 67-69, 156-161 Pressure points for Intra-osseus infusion 68 haemorrhage control 66 Intraperitoneal haemorrhage Pringle's manoeuvre 86, 290 - methods of assessment Recombinant factor VIIa 75, 247-250 (rVIIa) 67, 85, 199, 288 Intravenous fluids 70-72 Retrohepatic caval bleeding Ligation of arteries and veins 85-89, 289-299, 305-307 to control haemorrhage Pulse rate 53 89, 303-309 Resuscitation 44, 55-74 Limb elevation 67-69 Sagar splint 67, 71 684 Sources of major blood loss 50 Index.qxd 28/09/2004 15:58 Page 685 Index

Splenic injury 87, 283-284 Chilblain 587 Splinting fractures and soft Clinical features 583-584, tissue injuries 67- 72, 586-588 96, 100, 156-161 Epidural 126, 564, 589-590 Tourniquet 66-67, 97, 99, Fasciotomy 154-156, 589 151, 195, 231-233 First aid 584-585 Tractotomy to control lung Freezing cold injuries 587 bleeding 79, 87, 378-379 Frostbite 588-590 Triage 107-112 Frostnip 588 Vascular grafts and shunts Hypothermia 80, 583-586 80, 89, 90, 207-208 "Immersion foot" 586-587 Vascular injuries 89, 193-226 Incidence 582 Venous cannulation 68, Local cold injury 586-590 655-656 Military causes 583 Venous cut down 68, 653-655 Near drowning 591 Wound dressing 66, 95, 103, Non-freezing cold injuries 586 245 Nursing care 589, 590 Clarithromycin (Klaricid) 138-139 Pathophysiology 583-584, Cling film 506-507, 513, 523 586-588 Close Support Medical Regiment Resuscitation 585-586 113 Re-warming 585-586 Closed nerve injury, management Secondary drowning 591 498-499 Surgery 590 Clostridium botulinum 146 Transfer 584, 590 Clostridium perfringens 134, 141, "Trench foot" 586-587 142 Triage 584 Clostridium septicum 134 Colloid infusion 68 Clostridium species 95 Colon 271-283 Clostridium tetani 134, 140 Blood supply 273 Clotting adjuncts 67, 85, 199 Closing the lateral space Coagulopathy 80 281, 282 Co-amoxyclav (Augmentin) 137, Comparison with small bowel 138, 425, 463, 466 injuries 271 Codeine phosphate 123 Double-barrelled stoma Coeliac axis 307-308 280-282 Cold injury End colostomy 280-282 Alcohol, role of 589 End-to-side anastomosis Amitriptyline, pain relief 590 279-280 Analgesia 589, 590 Exteriorisation 87, 277-278 Cardiopulmonary Features of perforation 272 resuscitation (CPR) 585 Hartmann's procedure 282-283 685 Index.qxd 28/09/2004 15:58 Page 686 Index

Colon (cont) Thigh 171-172 Ileocolic anastomosis 279 Treatment 155-156 Left hemicolectomy 273 Upper arm 164-165 Loop colostomy 277-278 "Complete traumatic Management of extensive or hemipelvectomy" 317 contaminated injury Compound analgesic preparations 274-283 123 Mesentery, approximating 280 Compound Nerve Action Potential Mobilisation and inspection (CNAP) 498 272-274 Compressible / non-compressible Mucous fistula 280-282 haemorrhage 65-72, 193 Rectal injury 275, 282-283 Computerised tomography (CT) Resection 278-279 199, 294-250, 363, 392, 400, Retroperitoneal injuries 271 408, 412, 413, 415, 470 Right hemicolectomy 272 Concussion 406 Sigmoid colectomy 273 Coning 387-388 Simple repair 274 Conjunctiva 434 Stapled anastomosis 279-280 Contrast swallow 363 Transverse colectomy 273 Control of bleeding - see Circulation Colostomy 277, 280-282 and Haemorrhage Control Coma 394, 396-397, 400, 406, 407 Convulsion/epilepsy 388, 392, Combat body armour (CBA) and 417, 581 helmet design 9 1% Copper sulphate 524 Combitube 61 Cord damage, estimating level Combopen 35 477, 478, 479 Command and control 607-608, Cordons, major incidents 607-608 611 Core temperature measurement 580 Common iliac artery 219-220, 309 Cornea Communication, major incident Abrasions 433-434 609, 611-612 Examination 432-433 ComPAC ventilator 566-567 Foreign bodies 433 Compartment syndrome 96, 100, Infection (infectious keratitis) 154-156 434 Abdominal 311-312 Coronary artery injury and Burns 522 occlusion 358 Clinical features 155 Coup and contre-coup injury Forearm 167-168 386-387, 407 Hand 169 Craniectomy 402-403, 409-411, 412 Limb 154-156 Craniotomy 409, 411 Lower leg 174-177, 178, 179 Cricoid pressure 556, 559, 630-636 686 Pathophysiology 154-155 Cricothyroidotomy 59, 470, 630-636 Index.qxd 28/09/2004 15:58 Page 687 Index

Critical care - see Intensive Care 89-90, 253-259, 283-284, Critical Care Air Support Teams 287-292, 300, 303-307, (CCAST) 620 376-381, 467-468 Critical limb ischaemia 89 Control of enteric spillage 79 Crookham halter 68, 72 Critical limb ischaemia 89, 197 Crush injuries 162-163, 244 Decision making 81 Crystalloid infusion 70 Determinants of outcome 79 Cushing's Response 388 Disadvantages 81 Cutaneous ureterostomy 338, 339 Draping the wound 83 Cyanide poisoning 37-38, 45-46 Embolisation 90 Burns, inhalation 504 Feeding 94 Clinical features 38 Hilar clamping 87, 376 Cyanogen bromide 37 Hypothermia 80 Cyanogen chloride 37 Identifying the source of Detection 32-33, 37 bleeding 83, 256-259 Detoxification 37 Incision and extension 83 Formulation 37 Indications 82 Hydrogen cyanide 37 Inferior vena cava (IVC) Pathophysiology 37 85-89, 289-299, 305-307 Sodium nitrite and sodium Initial operation 83 thiosulphate 38 Laparotomy 83, 84, 254-260 Treatment 38 Ligation of arteries and veins Cyclizine 119 89 Cyclopentolate 425 Liver injury, 85-87, 287-292 Lung injury 87, 353-356 Damage Control Surgery (DCS) Lung resection 376-381 79-94, 193, 254 Lung rotation 87 Abdominal compartment Measuring clotting times 80 syndrome 94, 311-312 Metabolic acidosis 80 Abdominal visceral injury 87, 'Minimimal transfusion' 88 approach 82 Amputation 80, 229-231 Missed injuries 93 Aortic clamping 84-86, 305, Multi-visceral injuries 80 375 Numbers of casualties requiring Autotransfusion 82 DCS 81 Balloon tamponade 66, Packing 83, 85, 93, 289, 300, 86-88, 290, 306 303-304, 467-468 Chest wound 87, 361, 371 Perforation 87 Clotting adjuncts 67, 85, 199 Peroperative indications 82 Coagulopaphy 80 Preoperative selection 82 Control of bleeding 79, 85, Pringle's manoeuvre 86, 290 687 Index.qxd 28/09/2004 15:58 Page 688 Index

DCS (cont) Diarrhoea, tropical causes 549-551 Re-operation 92, 93 Diathermy 403 Restoring normal physiology Diazepam 35-37, 392 92, 568-577 Diclofenac 123-124 Retrohepatic vena cava Die of Wounds (DOW) 7 85-87, 289-299, 305-307 Diffuse axonal injury 406 Re-warming 80 Diffuse brain injury 406 Splenic injury 87, 283-284 Digital subtraction angiography Tactical situation 93 (DSA) 199 Temporary abdominal closure Dihydrocodeine 123 79, 90- 91 Dimercaprol (British Anti-Lewisite Tractotomy 79, 87, 378-379 BAL) 40 Triage 107-113 Diplopia 424, 445, 451 Vascular graft or shunt 80, Disability/neurological status 53 89, 90, 207-208 Dislocation 156-157 - see Fractures Vascular injuries 89, 193-226 Acromioclavicular joint 181 Dead casualties, major incident Ankle 189-190 610 Elbow 183 Decompression, - see Glenohumeral joint 181-183 Compartment Syndrome Hanging arm method of Decontamination after chemical shoulder reduction 182 attack 33-34 Hip 186-187 Deep vein thrombosis/pulmonary Hippocratic method of embolism shoulder reduction 182 Clinical features 191 Knee 188-189 Prophylaxis 97, 191-192 Kocher's method of shoulder Treatment 192 reduction 182, 184 Definitive care 44, 76 Methods of stabilisation Delayed primary closure 96, 104, 157-161 527 Patella 189 Depressed skull fracture 413-414 Dissociative disorders (hysteria) Dermatome, for skin grafts 530- 602 531 Dobutamine 576 Dermatomes, sensory 478, 479 Donor site, split skin graft 531-532 Detector paper - one colour/three Dopexamine 576 colour 32-33 Doppler handheld probe 198 Dexamethasone 470, 508 Doppler ultrasound (Duplex) 199 Dextropropoxyphene 123 Double-barrelled stoma 280-282 Diagnostic peritoneal lavage (DPL) Doxycycline 145 248-249 Dressings 95, 103, 506-507, 513, 688 Diaphragm 283-285, 356-357 518-519, 520, 532, 534 Index.qxd 28/09/2004 15:58 Page 689 Index

Duodenum 292-297 Inner ear 463-465 Adjuncts 297 Labyrinthine concussion 464 Controlled fistula 296 Middle ear 462-463 Decompression 295 Nystagmus 464, 465 Drainage 90, 295 Otalgia 464 Gastro-jejunostomy 294, 295 Otitic barotrauma 463-464 Jejunal serosal patch 296, 297 Otorrhoea 415-416, 462, 463 Kocher's manoeuvre 292, 295 Packing 462 Major injury, management of Perilymph fistula 464 296-297 Pinna 459-461 Minor injury, management of Prochlorperazine 464 295 Protection 462, 463 Mobilisation 294-295 Repair 460-462 Octreotide 297 Sensorineural deafness 463, Operative findings 292-293 464, 465 Pathophysiology 292-293 Sofradex 462-463 Proton pump inhibitors 297 Temporal bone fracture Radiology 293 464-465 Temporary pyloric closure 295 Typanic membrane 462, Tube duodenostomy 296 463, 464 Dura mater 385-386 Vertigo 459, 464 Dural defects, management of Xylometazoline 464 404-405 Echelons of Medical Care (First - Fourth Line ) 112 Ear injuries Electrical burns/electrocution Amoxicillin 463 521-523 Antibiotics 462-463 Electrocardiogram (ECG), after Aural fullness 464 chest injury 362 Avulsion injury 460 Electromyography 486 Bismuth iodoform paraffin End colostomy 280-282 ribbon gauze (BIPP) End ileostomy 270 pack 462 Endoscopic retrograde Blast injury 462, 463 cholangio-pancreatography Co-amoxyclav 463 (ERCP) 299, 303 Ear canal 461-462 Endoscopy 363, 470 External ear 459-461 Endotracheal intubation 59, Facial nerve 456, 464-465 639-642 Gentisone HC 462-463 Energy transfer 11-23 Haematoma 459-460 Enopthalmos 423 Haemotympanum 462 Enteric fever Head injury 464-465 Ceftriaxone 546 689 Index.qxd 28/09/2004 15:58 Page 690 Index

Enteric fever (cont) Maxilla 451 Ciprofloxacin 546 Pelvis 321-323, 324-326 Clinical features 545-546 Pin care 326 Diagnosis 545, 546 Spine 480 Pathophysiology 544-545 Upper arm 164 Salmomella typhi 544 External iliac artery 219-220, 309 Treatment 546 Extra-anatomical bypass 210-211 Entonox Extradural haematoma (EDH) Cautions 122-123 407-411 Chest injury 129 Eye injury, - see Ophthalmic Injury Contraindications 125 Head injury 129 Facial injury 96, 97, 101, 455-456 Indications 122 Facial nerve 456, 464-465 Method of use 122 Falkland campaign 1982 1-2 Entrapment leading to limb False aneurysm 196 amputation 230, 232 Fasciotomy, - see Compartment Enucleation, eye 437 Syndrome Epidural analgesia 126, 564, Fat embolism 192 589-590 Femoral nerve block 126-127 Epistaxis, management of 448, Femoral vein cannulation 68, 467-468 653-655 Erb's Palsy 487 Femoro-femoral bypass graft Eschar/escharotomy 508, 516, 210-211 517-518 Fentanyl 558, 559, 561 Escherichia coli 135, 138 Field Hospital 112, 554 Etomidate 559, 560 Field surgical team 554 Evacuation, - see Aeromedical Finger sweep 57 Evacuation Flail chest 63, 349, 350 Evacuation syndromes 595 Flammacerium cream 518-519 Eviscerated bowel 245 Flammazine cream 518-519 Evisceration, eye 437 Flap, skin 529, 535-538 Exposure 53 Flucloxacillin 139, 521 Exteriorisation of colon 277-278 Fluid restriction 245 External fixation 159-161 Fluid resuscitation 72, 510-513 Femur 171 Fluorescein 425 Foot 179 Focal brain injury 406-416 Forearm 166-167, 185 Focused Abdominal Sonography Hand 168-169 for Trauma (FAST) 249 Knee 173 Fogarty balloon catheter 201-202 Lower leg 161, 177-178, 189 Foreign bodies 102, 403, 405, 481 690 Mandible 454, 456 Fractures - see Dislocation Index.qxd 28/09/2004 15:58 Page 691 Index

Acetabulum 186, 318 Splinting/stabilisation 67-68, Ankle 190 156-161, 163-180 Classification 152 Thomas splint 67, 72, 170-173 Clavicle 180-181 Traction 159, 480, 170-173 Elbow 183 Wrist 185 External fixation 159-161 Wound management 95-106, Femur 169-172, 173, 174, 154, 397-399, 455-456 175, 187-188 Zygoma 443-444, 450-451 Foot 179-180 Fragments, - see Patterns of Forearm 166-168, 183-185 Injury in Military Operations Frontal bone 450 Fragment wounds 2-5, 96, 97, 'Guardsman's 446 102, 403, 405 Hand 168-169, 185-186 Free tissue transfer 537-538 Hip 187-188 Freezing cold injuries 587 Humerus 163-165, 183 Frostbite 588-590 Immobilisation 67, 156-161 Frostnip 588 Internal fixation 161 Fuel-air and thermobaric weapons Knee 173 2, 27, 502 Le Fort classification 442, Fuller's earth 33 444, 445 Fundus 436 Long bones 50 Lower leg 173-178, 189 GA (Tabun) 34 Mandible 446-447, 451-455 Gallbladder 87, 298-299 Maxilla 445-446, 451 Approach 298 Nasal 466-467 Cholecystectomy 298 Open (compound) 151, 153 Cholecystostomy 298 Orbital blow out 445, 451 X-ray 299 Pelvis 68, 74, 313-326 Gardner-Wells' callipers 480 Plaster of Paris splint 156-159 "Gas gangrene" 141-142 Radiographs 156 Gastro-jejunostomy 286, 294, 295 Reduction and stabilisation 'Guardsman's' fracture 446 156 GB (Sarin) 34 Restoration of circulation 154 GD (Soman) 34 Ribs 49 Gentamicin 521 Sagar splint 67, 71 Gentisone HC 462-463 Scapula 181 Glasgow Coma Scale (GCS) 389, Skull 413-415 391, 395-396 Slings 69 Globe, - see also Ophthalmic Injury Spine 475-482 Anterior chamber 430-436 Splint Aluminium Malleable Chemical injury 435-436 (SAM), 67, 70 Conjunctiva 434 691 Index.qxd 28/09/2004 15:58 Page 692 Index

Globe (cont) Basal skull fracture 414-415 Cornea 432-434 Battle's sign 414-415 Fundus and retina 436 Blunt 386-387, 405-416 Hyphaema 430-431 Brain stem injury 400 Iris 431 Brain swelling 387-388 Laser injury 437 Burr holes 408-411 Lens 431-432 Classification of brain injury Management of rupture/ 386-388 penetrating injury Cerebral perfusion pressure 429-430 387 Pupil 431 Cerebrospinal fluid (CSF) 386 Red reflex 432 CSF leak 415-416, 417 Signs of injury 429 Coma 394, 396-397, 400, Sympathetic ophthalmia 437 406, 407 Vitreous 436 Computerised tomography Glycopyrolate 561 (CT) 392, 400, 408, Gram-staining 145, 146 412, 413, 415 Great vessels, injury of 374-376 Concussion 406 Gulf War 1991 1-2, 4 Coning 387-388 Contusion 407 Haematoma block 126 Convulsions/epilepsy 388, Haemodialysis/haemofiltration 577 392, 417 Haemorrhage - compressible, Coup and contre-coup injury non compressible 65 386-387, 407 Haemorrhage control, Craniectomy 402-403, haemostasis, - see Circulation 409-411, 412 with Haemorrhage Control Craniotomy 409, 411 Haemothorax 62-63, 352-353 Cushing's Response 388 Haemotympanum 462 Depressed skull fracture Hartmann's procedure 282-283 413-414 Head injury 385-417 Diathermy 403 Abscess 388, 417 Diazepam 392 Aeromedical evacuation 416, Diffuse axonal injury 406 625 Diffuse brain injury 406 Analgesia 128-129, 392 "Dry" burr hole 411 Anatomy 385-386 Dura mater 385-386 Antibiotics 138, 392 Dural defects, management Anticonvulsants 392-393 of 404-405 Arachnoid mater 385-386 Ear injury 464-465 Assessment 389-397 Extradural haematoma 692 AVPU 389, 393-394 (EDH) 407-411 Index.qxd 28/09/2004 15:58 Page 693 Index

Focal brain injury 406-416 Position/draping of casualty Foreign bodies 403, 405 on operating table 401 Further management of Post-operative management head injury casualties 416 404 General management Primary brain injury 386-387 389-397 Probability of intracranial Glasgow Coma Scale (GCS) haematoma 413 389, 391, 395-396 Pupil, assessment of 389, Haemorrhage, classification 391, 394 of 386 Pupillary dilatation 388, 408, Haemorrhage, operative 412 control 403-404, 410, 411 Racoon eyes 414-415 Head shave 392, 397, 401 Radiological assessment 392 Hydrocephalus 417 Raised intracranial pressure Hyperthermia 388 387-388 Infection 388, 417 Rhinorrhoea 415-416 Instruments for neurosurgery Ring sign for CSF leak 415 401, 402 Role 1, management at Laceration, intracerebral 407, 389-391 411, 412 Role 2-4 391-397 Ligaclips 403 Scalp laceration 397-399 Localising signs 394-395, Secondary brain injury 408, 412 387-388 Long term complications 417 Skin flap 399 Lorazepam 392-393 Skull fracture 413-415 "Lucid interval" 408 Skull X-ray 392, 400, 408, Mannitol 393 413, 414-415 Meningitis 388 Subarchnoid haemorrhage, Middle meningeal artery 407, traumatic 406 408, 413 Subconjunctival Mini-neurological haemorrhage 414, 429 assessment 393-397 Subdural haematoma (SDH) Motor or sensory deficit 388 411-413 Nursing care 393, 405-416 Tentorium cerebelli 388 Operative treatment, general Third cranial nerve palsy 388 393, 400-405, 407 Through-and-through wounds Otorrhoea 415-416 400 Oxycel 403 Transfer of casualty 416, 625 Pathophysiology 385-388 "Trauma flap" for head injury Penetrating 386, 400-405 411 Phenytoin 393 693 Index.qxd 28/09/2004 15:58 Page 694 Index

Head injury (cont) "Hostile action casualty system Triage of head injury (HACS) 5 casualties 390-391 Humby knife 530-531, 532 Venous sinus 385-386 Hyoscine 119 Ventilation 393 0.5% Hyperchlorite solution 33 Wound closure 397-399, Hyperthermia - see Heat Illness 404-405, 411 Hypertonic saline dextran (HSD) 72 Wound excision/aspiration Hyphaema 428, 430-431 403, 404 Hypopyon 433 Heart and great vessels - see Hypothermia - see Cold injury Cardiac Injury Hypovolaemic shock 50-53, 509, Heat illness 510-513 Assessment 580-582 Hypotensive resuscitation 68-72, Atropine 36-37, 582 244, 253-254 Clinical features 579-580 Compounding factors 582 Ibuprofen 117, 123-124 Convulsions 581 Ileo-colic anastomosis 279 Core temperature Ileostomy 268-270, 280-282 measurement 580 Ileus 310 Definition 579 Iliac arteries 219-220, 309 First aid 580-581 "Immersion foot" 586-587 Head injury 388 Immobilisation of fractures and Management, HDU/ITU soft tissue wounds 67-72, 581-582 156-161 Management Roles 2 and 3 Incident activation, at hospital 611 581 Incident officer 607 Pathophysiology 576 Incident response team (IRT) 554 Prevention 580 Callout 609, 618 Rhabdomyolysis 582 Equipment 617 Treatment 580-582 Medical Incident Officer Helmet removal 54-55 (MIO) 607, 615 Hepatic artery 307-308 Packaging 618-619 High dependency care (HDC) 568 Record keeping and hand over Hilar clamping 376 619 Homatropine 425 Requirements 615-617 Horizontal alignment, eyes 423 Safety 608-609 Horner's syndrome 488 Staff 616 Hospital acquired infection 138 Treatment at scene 610, Hospital response to major 618-619 incident 611-613 Infectious keratitis 434 694 Inoconstrictors 576 Index.qxd 28/09/2004 15:58 Page 695 Index

Inodilators 576 Necrotizing fasciitis 142-143 Inotropic drugs 575-576 Nightingale, Florence 131 Interdental eyelet wiring 452-453 Perforated gut/viscous - Intermaxillary fixation 452-453, 454 likely pathogens 134, 137 Incisions 97-99, 256 Plague 145-146 Individual Protection Equipment Postoperative infection (IPE) 32 - likely pathogens 135 Induction of anaesthesia 558, Primary surgery - role of 132 559-560 Infection (cont) Infection/infectious disease Principles of antibiotic 131-149 ; see also treatment 136 Antibiotics and Bacteria Prophylactic antibiotics 132 Amoebic dysentery 549-551 Proportion of battlefield Anthrax 144-145 casualties 131 Antibiotics - battlefield Reducing the risk of infection considerations 137 132 Antibiotics - choice of Resistant strains 136, 138 137-139 Ricin 132 Aseptic technique 132 Schistosomiasis 547-549 Bacteria 131-146 Scutari 131 Bacterial colonisation 133 Semmelweiss, Ignaz 131 Biological warfare/weapons Smallpox 146-147 131-132 Skin laceration/penetration Botulism 146 - likely pathogens 134, Burns 520-521 137 Definition of infection 133 Spread/transmission 131 Enteric fever 544-546 Tetanus 140-141 Factors contributing to Utility of laboratory support infection in battlefield 135-136 wounds 132-133 Inferior mesenteric artery 309 "Gas gangrene" 141-142 Inferior vena cava 85-88, 89, Grouping of pathogens 305-307 according to site/injury Infraorbital nerve, damage 424 133-135 Inhalational burns 6, 47, 503-504, Head injury/meningitis 388, 514-515 417 Instruments, neurosurgery 401, Infection control 132, 143 402 Malaria 541-544 Intensive Care (IC) in the field Necrotic or poorly perfused Adrenaline 576 wounds-likely Alfentanil 571 pathogens 134 695 Index.qxd 28/09/2004 15:58 Page 696 Index

IC in the field (cont) Femur 171, 188 Arterial line, indications, Foot 179-180 technique 572-573 Forearm 167, 183-185 Assets/equipment required Hand 168, 185 569-571 Hip 187 Cardiovascular support Humerus 165 572-576 Intramedullary nailing of Central venous line, femur 171 indications, technique Pelvis 321, 322 573-575 Spine 481 Definition 568 Internal iliac artery 219-220, 309 Dobutamine 576 Interposition vascular graft 80, Dopexamine 576 89, 90, 207-208 Haemodialysis/haemofiltration Intestinal obstruction 310 577 Intimal flap 195, 202 High dependency care (HDC) Intra-osseous infusion 68 568 Intraperitoneal haemorrhage Indications 568 - methods of assessment 50, Inoconstrictors 576 75, 83, 247-250, 256-259 Inodilators 576 Intravenous fluids 70-72 Inotropic drugs 575-576 Intravenous urogram (IVU), Midazolam 571 technique 331 Morphine 571 Iris 431 Noradrenaline 576 Irrigation of wounds 103 Nutrition 576-577 Isoflurane 558, 560, 561, 566 Propofol 571 Renal support 577 Jaw - see Maxillofacial Injury Respiratory support, Jaw thrust 57 indications and technique Jejunal serosal patch 296, 297 571-572, 578 Joint dislocation - see Dislocation Staff 569 Joint wounds 96, 101 Ventilatory settings 571-572 Warning signs that casualty Ketamine hydrochloride 120-121, requires IC support 558, 559, 560, 562 568-569 Ketorolac 123-124 Intercostal nerve blocks 63, Killed in Action (KIA) 7 126-128, 349 Klebsiella species 135, 136 Internal cardiac massage 371 Klumpke's Palsy 487 Internal fixation 161 Knee disarticulation 239 Ankle 190 Kocher's manoeuvre 292, 294-295 696 Clavicle 180-181 Index.qxd 28/09/2004 15:58 Page 697 Index

Labyrinthine concussion 464 pulmonary embolism Lacri-lube 425 (PE) 191-192 Laparoscopy 250 External fixation 159-161 Large bowel, see Colon Fasciotomy 155-156, 164-165, Laryngeal injury, see Neck Injury 167-168, 169, 171-172, Laryngeal mask airway (LMA) 61 174-177 Laryngoscopy 469-470 Fat embolism 192 Lateral compression (LC) fracture Features of war injuries 151 of pelvis types 314-315 Fracture types 152 Laser injury, eye 437 Frequency of injury 151 Lebanon Israeli-PLO War 6 Examination 50, 153 Le Fort classification of maxillary Immobilisation 67-68, 156-161 fractures 442, 444, 445 Internal fixation 161 Left gastric artery 307 Ischaemia 195, 197 Left hemicolectomy 273 Joint dislocation 157 Lens, eye 431-432 Life-threatening injuries 151 Levels of command, at major Limb-threatening injuries 151 incident 607-608 Lower limb 169-180, 186-191 Lewisite 39-41 Management at Role 1 Lids, eye 152-154 Burns 428 Management at Role 2 or 3 Everting the lid 427 154-156 Examination 426 Mechanism of injury 151 Foreign bodies 426 Mine injury 227 Protection 428 Plaster of Paris splint 156-159 Wounds, management of Radiographs 156 426-428 Reduction and stabilisation 156 Ligaclips 403 Restoration of circulation Ligaments 100 154, 201-211 Lignocaine (Lidocaine) 125-126 Sagar splint 67, 71 Limb injuries - see also Fractures Skin cover for limb wounds and Dislocations 95-96, 162, 529-538 Aeromedical evacuation Slings 69 625-626 Splint Aluminium Malleable Amputation 227-242 (SAM) 67, 70 Antibiotics 96, 97, 137 Splinting/stabilisation of Compartment syndrome fractures/soft tissue 154-156 injuries 67-68, 156-161 Crookham halter 68, 72 Thomas splint 67, 72, 170-173 Crush injuries 162-163 Traction 159, 170-175, 178,180 Deep vein thrombosis (DVT)/ Traction splint 67-68, 71 697 Index.qxd 28/09/2004 15:58 Page 698 Index

Limb injuries (cont) Pleural analgesia 127 Upper limb 163-169, 180-186 Regional techniques 126, 558, Vascular injury 193-226 564 Wound excision 97-101 Safety 125 Wound management 95-106, Spinal 126, 564 154 Local cold injury 586-590 Liver 85, 287-292 Localising signs, after head Abscess 291 injury 394-395, 408, 412 Approach 288-289 Log roll 74 Biliary fistula 87, 291-292 Long bone fractures, suspicious Classification of injury features 50 187-188 Long saphenous vein cut down Complications of injury 68, 653-655 291-292 Loop colostomy 277-278 Complications of packing 289 Loop ileostomy 268, 269 Compression 85-87, 289-290 Lorazepam 392-393 Control of bleeding 85-87, Lower respiratory tract infection 138 88, 288, 289-290 Lund and Browder chart 515, 516 Haematoma 291 Lung injury 353-356, 376-381 Haemobilia 291 Blast lung 61, 354-355 Packing 85-87, 289-290 Burns 503, 508 Pathophysiology 287-288 Contusion 49, 353-355 Pringle's manoeuvre 86, 290 Flail chest 63, 349, 350 Resection 290, 291 Haemothorax 62-63, 352-353 Retrohepatic caval injury Hilar clamping 376 85-89, 305-307 Laceration 377-379 Lobectomy, lung 379 Lobectomy 379 Local analgesia Open pneumothorax Adrenaline and 125 ("sucking chest wound") Bupivicaine 125, 558 62, 351-352 Epidural 126, 564 Pneumonectomy 379-380 Femoral nerve block 126 Pneumothorax 49, 62-63, Haematoma block 126 349-352 Intercostal nerve block Rib fractures 49, 348-349 126-127 Surgical emphysema 48, 352 Lignocaine (Lidocaine) 125, Tension pneumothorax 62, 63, 558 351 Limitations in the field Tracheobronchial injury 124-125 355-356, 380-381 Maximum safe dose (MSD) Tractotomy 378-379 698 125 Index.qxd 28/09/2004 15:58 Page 699 Index

Major incident medical Dipstick antigen-capture management assay 542 Blood transfusion 612-613 Doxycycline 543, 544 Command and control Fansidar 544 607-608, 611 Fever patterns 541 Communication 609, 611-612 Malarone 542, 543, 544 Cordons 607-608 Mefloquine 543, 544 Dead casualties 610 Merozoites 541 Definition 605 Pathophysiology 541 Equipment 606 P. falciparum 541, 543 Explosives Ordnance Disposal P. malariae 543 (EOD) 608, 616 P. ovale 543 Hospital response 611-613 P. vivax 543 Incident activation, at Primaquine 543 hospital 611 Proguanil hydrochloride 543 Incident Officer 607 Prophylaxis 542-543 Investigations 613 Quinine 544 Levels of command, bronze, Resistant strains 542-544 silver, gold 607-608 Schizonts 541 Major Incident Medical Sporozoites 541 Management and Treatment 543-544 Support (MIMMS) 606 Tumour necrosis factor 541 Medical Incident Officer 607 Malingering and feigned illness 603 METHANE 609 Man Portable Chemical Agent Planning 605-606, 611 Detector (MCAD) 33 Preparation 605-606 Mandibular fractures 446-447, Response at scene 607-620 451-455 Safety 608-609 Mangled Extremity Severity Score Training 606 (MESS) 229-230 Transfer 613 Mannitol 393, 519, 522 Transport 610, 619-626 Mass casualty situation 108-109 Treatment at hospital 612-613 Analgesia 129-130 Treatment at scene 610 Burns 525 Triage 609-610, 612 Principles 107 Malaria Priorities 107-109 Chloroquine 543, 544 T (Treatment) System Clinical features 541-542 107-109 Complications of P.falciparum Triage sieve for treatment 542 109-110 Diagnosis 542 Triage sort for transfer 110-112 699 Index.qxd 28/09/2004 15:58 Page 700 Index

Mass casualty situation (cont) Malocclusion 423,442, 446, 451 Medical cases 112 Mandibular condyles, Psychiatric cases 112 fractures of 446-457, 452 Maxidex 425 Mandibular fracture 446-447, Maxillary fractures 445-446, 451-455 451-452 Maxillary fractures 445-446, 451 Maxillofacial injuries Middle third fractures Aeromedical evacuation 626 443-446, 450-451 Anatomy 440 Miniplate fixation 451, 453 Antibiotics 137-138, 449 Nursing 457 Arch bar 453 Orbital blow out fractures Bimanual reduction of a 423-426, 445, 451 Le Fort 3 fracture 451, 452 Orbital decompression 450-451 Blunt injury 441 Pathophysiology 439-441 Control of bleeding 448 Penetrating injury 439-441 Diplopia 424, 443, 445 Radiological investigation Distraction osteogenesis 454 445, 447-448 Epistaxis 448 Respiratory embarrassment Examination 441-447 446, 451, 452 External fixation 451, 454 Restricted eye movements Facial nerve injury 456, 422, 424, 429, 443, 445 464-465 Retrobulbar haemorrhage 450 Frontal bone, fracture of 450 Skull vault fractures 443, 450 'Gagging' (open bite) 447 Soft tissue loss 456 General management of Supraorbital rim, fracture of 450 facial fractures 447-450 Teeth, management of 452 'Guardsman's fracture' 446 Transfer of casualties 458 Horizontal alignment, loss of Triage for transfer 458 423, 445 Upper third fractures 443, 450 Indications for a surgical Wisdom teeth, management of airway 457 457-458 Interdental eyelet wiring Wound closure 456 452-453 Wound excision 455-456 Intermaxillary fixation 454 Zygoma 422, 423, 443-444, Infraorbital hypoaesthesia 424 450-451 Le Fort classification of Maximum safe dose (MSD) of maxillary fractures 442, local anaesthetic 125-126 444, 445 Mechanical bowel obstruction 310 Lower third fractures Medical Incident Officer 607 446-447, 451-455 Medical Section 112 700 Index.qxd 28/09/2004 15:58 Page 701 Index

Medically unexplained symptoms Physical injury and (MUS) 603, 604 psychiatry 598-599 Medimech Auto Injector 118 Physical restraint 594 Meningitis 388 Post combat or traumatic Mental state disorders 603-604 Hypercarbia 45 Post traumatic stress disorder Hypovolaemic shock 51 (PTSD) 603-604 Hypoxia 45 Prevention of acute stress METHANE 609 reaction 598 Methicillin-resistant Psychological debriefing 604 Staphylococcus aureus Psychotic disorders 601 (MRSA) 136 Somatisation 602 Metoclopramide 119 Suicidality 601 Metronidazole (Flagyl) 137, 138, Symptoms 594-595 425 Transfer 597-598 Midazolam 558, 563, 571 Violence 594-595 Military psychiatry Mine injury 27, 227-228 Acute psychiatric disorders Mini-neurological assessment (APD) 593 393-397 Acute psychological Miniplate fixation 451, 453 disorders 601-603 MIST 44 Acute psychological Modular Transportable Surgical reactions to combat Facility (MTSF) 553 593-595 Monitoring Acute stress reactions (ASR) Burns 512-513, 514, 519-520 593, 596-598 Head injury 394 Credibility 596 Resuscitation, effects of 73 Dissociative disorders Vascular surgery, after 211 (hysteria) 602 Morphine sulphate Evacuation syndromes 595 Anaesthesia, use in 557, Examination 595-596, 597 558, 559, 561, 571 Malingering and feigned Antiemetic requirement 119 illness 603 Contraindications 120 Medically unexplained Dose 118-119 symptoms (MUS) 603, Mechanism of action 118 604 Medimech Auto Injector 118 Medication 594-595, 597 Naloxone 119-120 Organic cause of psychiatric Patient Controlled Analgesia symptoms 599-600 119 Personality disorder 602 Route of administration 118-119 Side effects120 701 Index.qxd 28/09/2004 15:58 Page 702 Index

Motion sickness 624 Dexamethasone 470 Mouth to mask ventilation 64 Endoscopy 470 Mouth to mouth/mouth to nose Examination 48, 469 ventilation 64 Injury/wounds 45, 47, 48 Moyer's solution 526 Laryngo-tracheal injury 48, Mucous fistula 270, 280-282 355 469, 472 Multi-drug resistant Klebsiella Laryngoscopy 469-470 species 136 Major injury 470 Muscle relaxants 558 Minor injury 469-470 Mustards 39-41 Needle cricothyroidotomy Myocardial contusion 357 61, 630-633 Myoplastic repair after Oesophageal injury 358-359, amputation 229, 235-236 381-384, 472 Penetrating neck wounds Naloxone 119-120 48, 470-473, 556 Nasal injury Pressure dressing 66 Air sinuses 448, 451 Surgical airway 59-61, 556, Anterior nasal packing 467- 633-638 468 Tracheostomy 59, 470, 636-638 Bismuth iodoform paraffin TWELVE 48 ribbon gauze (BIPP) Vascular injury 472 pack 467 Venous distension 48 Co-amoxyclav 466 Zones 1-3 470-472 Epistaxis 448, 467-468, Necrotizing fasciitis 142-143 Fracture 466-467 Needle thoracocentesis 62, 360, Nasal tampon 466, 467 644-645 Posterior nasal packing 468 Neostigmine 561 Septal haematoma 465-466 Nephrectomy 332-335 Wound management 467, 468 Nephrostomy tube 334-335 Nasopharyngeal airway (NPA) Nerve injury 58, 630 Anatomy 483, 484 NBC filter, use in anaesthesia 567 Axillary nerve 488 NBC suits 32 Axon 484 Near drowning 591 Axonotmesis 484-485 Neck Brachial plexus 486-488, 499 Blunt trauma 469-470 Cable graft 496 Cervical spine 47-48, 55, 469 Classification 483-485 Computerised tomography Closed injuries, 470 management 498-499 Cricothyroidotomy 59-61, 70, Compound Nerve Action 702 633-636 Potential (CNAP) 498 Index.qxd 28/09/2004 15:58 Page 703 Index

Delayed repair, Avizafone 35 consequences of 494 Clinical features 35, 46 Electromyography 486 Combopen 35 Erb's Palsy 487 Detection 32-33,36 Examination 486 Diazepam 35-37 Facial 456, 464-465 Formulation 34 Factors influencing recovery GA (Tabun) after repair 497-498 GB (Sarin) Femoral nerve 490 GD (Soman) Horner's syndrome 488 Interactions 37 Infraorbital nerve 424 Nerve Agent Pretreatment Investigation 486 Sets (NAPS) 35 Klumpke's Palsy 487 Pathophysiology 34 Management 485-499 Pralidoxime 35-36 Median nerve 488, 489 Pretreatment 35 Monitoring recovery 496 Treatment 36 Musculocutaneous nerve 488 VX nerve agent 34 Nerve conduction studies 486 Nerve Agent Inhibition Enzyme and Nerve grafts 496 Alarm Detector (NAIAD) 33 Nerve repair 100, 492-498 Nerve Agent Pretreatment Sets Neurapraxia 483-484 (NAPS) 35 Neurilemmal sheath 484 Neurapraxia 483-484 Pathophysiology 483-485 Neurogenic shock 478 Peroneal nerve 490-491, 492 Nightingale, Florence 131 Penetrating wounds, Nissen-Thal operation 384 management of 492-493 Nitrogen and sulphur mustards Plastic pen test 486 39-91 Posterior tibial nerve 491-492 Nitrous oxide 560 Radial nerve 489-490, 491 Noise and Aeromedical Recognition of injury 485-486 evacuation 623 Schwann cell layer 484 Non-compressible injury 65-68, Sciatic nerve 490 243, 244, 245 Timing of surgery 493-494 Non-freezing cold injuries 586 Tinel's sign 497 Non-steroidal anti-inflammatory Ulnar nerve 489, 490 drugs (NSAIDs) Wallerian degeneration 484 'Balanced analgesia' 124 Wound management 100, Contraindications 124 492-493 COX-2 inhibitors 124 Nerve agent poisoning 34-37, 45, 46 Diclofenac 123-124 Atropine 35-37 Dose/route of administration Atropine poisoning 36-37 123 703 Index.qxd 28/09/2004 15:58 Page 704 Index

NSAIDs (cont) Acetazolamide 425 Ibuprofen 117, 123-124 Aeromedical evacuation Ketorolac 123-124 429-430, 626 Mechanism of action 123 Amethocaine 425 Noradrenaline 576 Anatomy 419, 420, 421 Northern Ireland bullet wounds Anterior chamber 430-436 1969-1979 5 Antibiotics, systemic and Nose - see Nasal Injury topical 424, 425 Nuclear injury Assessment, history and Blast effects 29-30 examination 419-421 Blindness 29 Atropine 425 Burns 29-30 Azithromycin 425 Causes of injury 28-29 Benoxinate 425 Fission reaction 28 Burns 428, 523, 524 Fusion reaction 28 Cartella shield 428 Light flash 29 Ceftriaxone 425 Nuclear explosion 28 Chemical injury 420, 435-436 Radiation effects 28, 30 Chemosis 429 Radiation enhanced nuclear Chloramphenicol 425 device 28 Ciprofloxacin 425 Treatment 30-31 Co-amoxyclav 425 Nutrition 576-577 Conjunctiva 434 Nystagmus 464 Cornea 432-434 Cyclopentolate 425 Oedemagens Diplopia 424 Chlorine 41-42 Enophthalmos 423 Pathophysiology 42 Enucleation 437 Phosgene 41-42 Everting the eye lid 427 Treatment 42 Evisceration 437 Oesophageal disruption 48, Facial asymmetry 423 358-359, 381-384, 472 Fluorescein 425 Ofloxacin 425 Foreign bodies 424, 426, 432, Ondansetron 119 433, 434 "Open book injury" of pelvis Fractures, general 315-317 management of facial Open joint wounds 96, 101 fractures 447-450 Open pneumothorax ("sucking Fundus and retina 436 chest wound") 62, 351-352, General measures 424 644-650 Globe injury 429-430 Ophthalmic injury Homatropine 425 704 Abrasions, corneal 432, 433 Horizontal alignment, Index.qxd 28/09/2004 15:58 Page 705 Index

assessment of 423 "Super" glue/bio-glue 430 Hyphaema 430-431 Sympathetic ophthalmia 437 Hypopyon 433 Timolol 425 Infectious keratitis 434 Visual acuity 420-421 Infraorbital hypoaesthesia, Vitreous 436 infraorbital nerve damage 424 Zygoma 443-444, 450-451 Iris 431 Ophthalmic preparations 425 Lacri-lube 425 Ophthalmoscope 431-432, 436 Laser injury 437 "Opsite sandwich" 91,93 Lens 431-432 Orbit Lid wounds 426-428 Blow-out fracture 424, 445, 451 Limited jaw movement 422, 423 Decompression 450-451 Malocclusion 423 Diplopia 424, 445, 451 Maxidex 425 Enophthalmos 423 Maxillary fractures 445-446, 451 Examination 423-424 Metron.idazole 425 Facial asymmetry 423 Ofloxacin 425 Foreign bodies 424 Ophthalmic preparations 425 Fracture 425 Ophthalmoscope 431-432, 436 Horizontal alignment 423 Orbital decompression 450-451 Infraorbital hypoaesthesia 424 Orbital injury 423-426, 445, 451 Investigations 425 Pathophysiology 419, 428 Proptosis 423 Proptosis 423 Restriction of eye movement Protecting the injured eye 428 424, 445, 451 Pupil 431 Oropharyngeal airway (OPA) 58, 629 Raised intraocular pressure Otalgia 464 425, 431 Otitic barotrauma 463-464 Red reflex 432 Otorrhoea 415-416, 462, 463 Reflexes, direct and consensual Oxford Miniature Vaporiser (OMV) 422-423 566, 567 Relative afferent pupil defect Oxycel 403 (RAPD) 422-423 Oxygen administration 55, 565 Repair of ruptured globe Oxygen concentrators 565 429-430 Restricted eye movement P's, the six 197 422, 424, 429, 443, 445 Packaging 76, 245-246 Retinal detachment 436 Packing 83 Retrobulbar haemorrhage 450 Abdomen 254-259 Snellen Chart 420-421 Complications of 85, 93, 289 Subconjunctival Ear 462 haemorrhage 414, 429 Liver 85, 289-290 705 Index.qxd 28/09/2004 15:58 Page 706 Index

Nose 467-468 Pancuronium 558 Pancreas 300 Paracetamol 123-124 Pelvis 85, 323 Partial nephrectomy 334-335 Removal of packs 93, 94 Patch angioplasty 209 Retroperitoneum 85, Patient controlled analgesia 303-304, 331-332 (PCA) 119, 561 Pain Patterns of injury in military Analgesia 115-130 operations 1-10 Assessment of pain 116-117 Abdomen 243-244 Effects of inadequate pain Ballistic injury 1-8 control 115-116 Blast 6, 23-27, 244 Inadequate pain relief Blunt injury 3, 6, 11, 244 perception 115 Bullets 1-5 Physiological response 115 Burns 6, 27 Principles of management Combat body armour (CBA) 115 and helmet 9 Pancreas 299-303 Combination injury 3, 7 Abscess 303 Comparison of bullet and Approach 292, 294-295, 299 fragment injury 2, 3 Complications of injury Complexity of injury 5, 7 302-303 Diagnostic difficulties 4 Damage control surgery 85, Die of Wounds (DOW) 7 87, 90 Fragment injury 2-5 Drainage 87, 90, 300 Fragmentation devices Endoscopic retrograde random and "improved" cholangio-pancreatography 3-4 (ERCP) 303 Fuel-air and thermobaric Fistula 87, 303 weapons 2, 27, 502 Investigation 299 Head injury 385 Kocher's manoeuvre 292, "Hostile action casualty 294-295 system" (HACS) 5 Major injury, management Improving outcome following 300-301 injury 8-9 Minor injury, management Injury to critical areas 5, 7 301-302 Killed in Action (KIA) 7 Packing 300 Magnitude and lethality of Pancreatectomy 300-301, 303 fragments and bullets 3-5, 7 Pancreatitis 303 Multiple penetrating injuries Pseudocyst 303 4-5, 7 Repair 301-302 Novel weapons 2, 27, 502 706 Resection 300-301, 302 Penetrating injury 1-11 Index.qxd 28/09/2004 15:58 Page 707 Index

Predicted mortality without Pelvic external fixator treatment 8 321-323, 324-326 Regional injuries 1-2 "Perineal spliting type" injury Surgical and anaesthetic 318, 319 skills 5 Pin care 326 Thermal injury 6, 27, 501-506 Pubic diastasis, examining Vascular injury 193-196 for 319 Pedicle graft 537 Sacroiliac ligaments 313, 315 Penetrating injury - see Ballistic Soft tissue trauma 318 Injury Superior gluteal arteries 313 Penicillin 137, 139 Traction 170-171, 322 Penile injury 345 Treatment 321-326 Pelvic injury 313-326 Urological injury 319, 343-345 Acetabular fractures 318 Venous drainage 313 Anatomy 313 Vertical shear (VS) injury 317 Anteroposterior compression "Windswept pelvis" 315 (APC) fracture types 1-3 Peptococcus species 134 315-317 Peptostreptococcus species 134 Assessment, history, Pericardiocentesis 64-65, 360, examination and 371-373, 650-653 investigations 318-321 Perilymph fistula 464 "Complete traumatic "Perineal spliting type" injury hemipelvectomy" 317 318, 319 Complications 323-324 Perinephric haematoma 332, 336 Features suspicious of injury Perirenal (Garota's) fascia 330, 50, 318-320 332 Fractures 68, 74, 313-318 Personality disorders 602 Immobilisation 321 Pharynx - see Neck Injury Internal iliac arteries 313 Phenytoin 393 Investigations 320, 321 Phosgene 41-42 Lateral compression (LC) Phosphorus burn 523-524 fracture types 1-3 Physical injury and psychiatry 314-315 598-599 Major injury 314-317 Physical restraint 594 Management at Role 1 and 2 Pinna 459-461 318-321 Plague 145-146 Management at Role 3 and 4 Plastic and reconstructive surgery, 321-323 - see Wound Management Minor pelvic fractures 317-318 Advancement flap 534, 535 "Open book injury" 315-317 Aims 527 Pathophysiology 313-318 Applying the graft 532-534 707 Index.qxd 28/09/2004 15:58 Page 708 Index

Plastic surgery (cont) Plaster of Paris splinting 156-159 Available techniques, the Plastic pen test 486 reconstruction ladder 528 Pleural analgesia Axial flaps 537-538 Pneumonectomy 379-380 Covering vital structures 529 Pneumothorax 62, 63, 349-352 Delayed primary closure 96, Portal vein 308 100, 527 Post combat or traumatic Dermatome 530-531 disorders 603-604 Donor sites for split skin Post traumatic stress disorder graft 531 (PTSD) 603-604 Donor site, management Practical procedures 531-532 Airway manoeuvres 629-642 Dressings 95, 103, 532, 534 Ashermann chest seal 643 Facial injury 96, 97, 101 Bowel surgery 260-283 Flaps 529, 535-538 Breathing manoeuvres Free tissue transfer 537-538 643-650 Graft take, optimising 529 Chest tube insertion Harvesting a split skin graft (Thoracocentesis) 530-531 646-650 Humby knife 530-531, 532 Circulation manoeuvres 650-656 Immobilisation 96, 100, 104, Endotracheal intubation 534 639-642 Microvascular anastomosis Femoral vein cannulation 537-538 655-656 Nerve repair 100, 492-498 General advice on performing Open joint wounds 96, 101 procedures 629 Pedicle 537 Guedel airway 58, 59, 629 Primary suture 96, 527-528 Knot tying 664 Random pattern flap 535-537 Nasopharyngeal airway Rhomboid flap 536, 537 (NPA) 58, 60, 630 Rotation flap 535 Needle cricothyroidotomy Scalp 96, 397-399 630-633 Split skin graft 528, 529-534 Needle pericardiocentesis Tendon repair 100, 664 650-653 Transposition flap 535, 536 Needle thoracocentesis Vascular techniques 100, 644-645 201-211 Nerve repair 493-498 V-Y advancement flap 537 Open pericardiocentesis Wound excision 96-101, 527 371 372, 651 Wound healing, optimising Oropharyngeal airway (OPA) 708 528 58, 59, 629 Index.qxd 28/09/2004 15:58 Page 709 Index

Peripheral venous cutdown Pulmonary embolism 97, 191 653-655 Pulmonary contusion 353-355 Principles of wound Pulmonary tractotomy 378-379 management 95-105, Pulse oximetry 198 658-665 Pulse rate 53, 109-110 Surgical cricothyroidotomy Pupil assessment 53, 388-389, 633-636 391, 394, 408, 412, 431 Surgical handicraft 656-665 Suture removal 658-659 Raccoon eyes 414-415 Technique of wound closure Radiation - see Nuclear Injury 660-665 Radiation enhanced nuclear Tendon repair 662, 664 device 28 Thoracocentesis 646-650 Raised intracranial pressure Tracheostomy 636-638 387-388 Vascular repair 201-211 Raised intraocular pressure 425, Predicted mortality 8 431 Premedication, anaesthesia Random pattern flap 535-537 118-119, 392-393, 556, 557 Rapid sequence induction 556, 559 Preoperative assessment Rectal injury 257, 282-283 555-557 Red reflex 432 Preoxygenation 559 Reflex, direct and consensual Pressure points for haemorrhage 422-423 control 66 Refrigeration 565 Primary brain injury 386-387 Regimental Aid Post (RAP) 112 Primary Care Casualty Receiving Regional anaesthesia 564-565 Ship (PCRS) 113 Rehabilitation after amputation 242 Primary survey 44 Relative afferent pupil defect Primary suture 96, 527-528 (RAPD) 422-423 Pringle's manoeuvre 86, 290 Renal support 577 Prochlorperazine 119, 464 Renal trauma 327-337 Propofol 558, 559, 560, 563-564, Aetiology 327-328 571 Approach, surgical exposure Proptosis 423 331-336 Proteus species 135 Blunt injury 327 Psoas hitch 338 Classification 328-329 Psychiatric symptoms, physical Clinical features 328 causes 589-599 Complications 337 Psychiatry see Military Psychiatry Indications for surgery Psychological debriefing 604 331-332 Psychotic disorders 601 Intravenous urogram (IVU), Pubic diastasis , examining for 319 technique 331 709 Index.qxd 28/09/2004 15:58 Page 710 Index

Renal trauma (cont) Rhinorrhoea 415-416 Investigation 328, 330-331 Rhomboid flap 536, 537 Major injury management Rib fracture 348-349 330-331 Ricin 132,144 Minor injury, management Right hemicolectomy 173 330 Ring sign for CSF leakage 415 Nephrectomy 332-334 Roles of Medical Care (Roles 1-4) Nephrostomy tube 334-335 112 Packing 332 Rotation flap 535 Partial nephrectomy 334-335 'Rule of Nines' 510, 511 Pathophysiology 327-330 Penetrating injuury 328 Sacral sparing, spinal injury 477 Perinephric haematoma 332, Sacroiliac ligaments 313, 315 336 Sagar splint 67, 71 Perirenal (Gerota's) fascia Sanders Oxygen 'T' 566, 567 330, 332 Scalp laceration 96, 397-399 Repair of renal lacerations Scene safety 44, 608-609 332, 334 Schistosomiasis 547-549 Respiratory support, indications Acute 547-548 and techniques 571-572, 578 Chronic 548-549 Restoration of circulation 154 Pathophysiology 547-549 Restricted eye movements 422, Praziquantel 549 424, 429 Treatment 549 Restricted jaw movement 422,423 Scrotum 96, 345-346 Resuscitation 44, 55-74, 557, 559 Scutari 131 Resuscitative laparotomy 68, 'Second look' laparotomy 261 80-87, 246 Secondary brain injury 387-388 Resuscitative thoracotomy 361, Secondary drowning 591 371 Secondary survey and packaging Retained bullets and fragments 44, 74-76 102-103 Semmelweiss, Ignaz 131 Retinal detachment 436 Sensorineural deafness 464, 465 Retrobulbar haemorrhage 450 Shunt - see Vascular Shunt Retroperitoneal haemorrhage, Sigmoid colectomy 273 management 85-87, 300, Sigmoidoscopy 248 303-309, 332 Skin cover 162 Reversal of anaesthesia 561 After amputation 236-237 Revision of the amputation stump Scalp injury 399 242 Skin graft 529-538 Re-warming 585-586 Skull fracture 413-415, 443, 450 710 Rhabdomyolysis 582 Skull traction 480 Index.qxd 28/09/2004 15:58 Page 711 Index

Skull X-ray 392, 400, 408, 413, Cord damage, estimating 414-415, 464-465 level 477, 478 Slings 69 Dermatomes 478, 479 Small bowel 260-270 Examination 476-477 Anastomosing bowel of Foreign body 481 unequal diameter Gardner-Wells' callipers 480 265-267 Immobilisation 478-479, 480 Anastomotic patency, testing Management 477-481 for 265 Neurogenic shock 478 Assessment of viability 261 Nursing 479, 480 End ileostomy 270 Pathophysiology 475-476 End-to-end anastomosis Penetrating injury 476, 480 263-269 Respiratory difficulties End-to-side anastomosis 267 477-479 Loop ileostomy 268-270 Sacral sparing 477 Mesenteric injury/haematoma Skull traction 480 260-261 Surgery, role of 481 Pathophysiology 260-261 Suspicious features, history Repair 261-262 47-48, 476 Resection, indications for 263 Sympathetic tone, loss of 477 Resection, technique Transfer 479-480 263-264 Turning frame, Stryker, Povey 'Second look' laparotomy 261 480 Side to side anastomosis Ventilatory support 477, 478, 266-267 479 Single perforation, Spleen/splenectomy 87, 283-284 management of 261-262 Splenic artery 307 Stapled anastomosis 265, Splint Aluminium Malleable 266, 269 (SAM) 67, 70 Small pox 146-147 Splinting fractures and soft Snellen chart 420-421 issue injuries 67-72, 96, Sodium nitrite and sodium 100, 104, 156-161 thiosulphate 38 Split skin graft 528, 529-534 Sofradex 462-463 Staphylococcus aureus 134, 137, Somatisation 602 138, 520-521 Spinal analgesia 126, 564 Stomach 285-287 Spinal injury Approach 285 Anatomy 475, 478 Pathophysiology 285 Blunt injury 476, 480 Repair of injuries 285, 287 Complications, prevention of Strategic evacuation 619 480-481 Streptococcus pneumoniae 138 711 Index.qxd 28/09/2004 15:58 Page 712 Index

Streptococcus pyogenes 134, Suture removal 658-659 136, 137, 138, 520-521 Sutures and ties, types of Stomal problems 311 659-665 Stump dressing/bandage, after Technique of wound closure amputation 233-234, 236 660-665 Subarachnoid haemorrhage, Tendon repair 662, 664 traumatic 406 Vascular repair 201-211 Subconjunctival haemorrhage Vertical mattress suture 660, 414, 429 662 Subdural haematoma (SDH) Wound healing 656-658 411-413 Suxamethonium 558, 560, 563 "Sucking chest wound" 62, Sympathetic ophthalmia 437 351-352, 643 Sympathetic tone, loss of 477 Suicidality 601 Syme amputation 242 "Super glue"/bio glue 430 Synthetic grafts 89, 207-208 Superficial fragment wound 96, 97 Systemic Inflammatory Response Superior gluteal artery 313 Syndrome (SIRS) 503, 525 Superior mesenteric artery 308 Suprapubic catheter, insertion Tactical evacuation 620 344-345 Teeth, management of 452, 457-458 Surgical airway 59-61, 508, 556, Temperature and Aeromedical 633-638 evacuation 621-622 Surgical decision making, Temporary abdominal closure 79, abdominal injury 250-253 90, 91,93, 259-260 Surgical emphysema 48, 352 Temporary wound cavity 16-23 Surgical Handicraft Change in presented area of All layers suture 660-661 missile 20 Bowel surgery 260-283 Clinical consequences 11, 19-22 Continuous suture 660-661, Compounding factors 20-23 662 Contamination 18-19 'Dog ends', dealing with Effect of missile fragmentation 662-663 13, 16, 21, 22 Drains 665 Effect of tissue properties 19-21 Gauge of suture 659, 665 Shape 17-18 Knot tying 664 Size 16-17 Needle, choice of 659-660 Wound track length 22-23 Nerve repair 493-498 Yaw 17-18, 21, 23 Principles of wound Tendon repair 100, 662, 664 management 95-105, Tension pneumothorax 62, 63, 658-665 351, 644-650 712 Subcuticular suture 662 Tentorium cerebelli 388 Index.qxd 28/09/2004 15:58 Page 713 Index

Testis, injury to 345-346 Contrast swallow 363 Tetanus 140-141 Coronary artery injury and Clinical features 141 occlusion 358 Human tetanus Decision making 360 immunoglobulin 140, 141 Diaphragmatic disruption Pathophysiology 140 356-357 Prevention 140-141 Electrocardiogram 362 Tetanus toxoid vaccine 96, 141 Emergency thoracotomy, Treatment 140 indications 361-362 Thermal injury - see Burns End cervical oesophagostomy "Thermopols" 565 383, 384 Thiopentone 558, 559, 560 Endoscopy 363 Third cranial nerve palsy 388 Examination 48, 359 Thomas splint 68, 72, 170-174 Flail chest 63, 349, 350 Thoracic injury - see also Breathing General overview 348-359 and Ventilation Great vessels, injury to Adult respiratory distress 375-376 syndrome (ARDS) 354 Haemothorax 62-63, 352-353 Aeromedical evacuation Heart and great vessels, 624-625 injuries to 357-358 Anterolateral thoracotomy Hilar clamping 376 364-365 Immediate thoracotomy, Aorta and great vessels 357, indications 361 374-376 Initial management 359-363 Aortography 363 Internal cardiac massage 371 Ashermann chest seal 359, Investigations 362 643 Laryngeal injury 355 Atrium 372, 373 Lobectomy 379 Bilateral anterolateral Lung injury 353-356, 376-381 thoracotomy 367-368 Lung laceration, repair of Blast lung 27, 354-355 377-379 Cardiac enzymes 363 Management 359-371 Cardiac laceration 373-374, Median sternotomy 368-370 375 Myocardial contusion 357 Cardiac tamponade 64, 358, Needle thoracocentesis 360 371-373, 650-653 Nissen-Thal operation 384 Chest drain (thoracocentesis) Oesophageal disruption 360, 640-650 358-359, 381-384 Chest X-ray, assessment of Open pneumothorax 262 ("sucking chest wound") Computed tomography (CT) 363 62, 351-352, 643 713 Index.qxd 28/09/2004 15:58 Page 714 Index

Thoracic injury (cont) Bilateral anterolateral Pathophysiology 347-348 thoracotomy 367-368 Pericardiocentesis 64, 360, Closure 365-367, 370 371-373, 650-653 Emergency thoracotomy, Pneumonectomy 379-380 indications 361-362 Pneumothorax 62-63, Median sternotomy 368-370 349-352 Posterolateral thoracotomy Posterolateral thoracotomy 365, 366 365, 366 Resuscitative thoracotomy Pulmonary contusion 361, 371 353-355 Subclavicular ("trapdoor") Pulmonary tractotomy 76, incision 370-371 378-379 Thoracoabdominal incision 364 Resuscitative thoracotomy, Thrombectomy 201-202 361, 371 Thrombosis 198 Rib fractures 348-349 Timolol 425 Simple pneumothorax Tinel's sign 497 349-350 Tissue loss 101, 162, 236, 455-456, Subclavicular ("trapdoor") 527-538 incision 370-371 Tissue viability 100 "Sucking chest wound" 62, Topical analgesia 351-352, 643 Catheterisation 126 Surgical emphysema 48, 352 Eye 126 Tension pneumothorax 62, 63, Torso trauma -role of surgery 79 351, 644-650 Total body surface area burned Thoracoabdominal incision 364 (%TBSAB) 502-503, 510, Thoracotomy, approach and 511, 515-516, 525, 526 instrumentation 363-364 Total intravenous anaesthesia Thoracotomy closure (TIVA) 562-564 365-367 Tourniquet 66-67, 97, 99, 151, Tracheobronchial injuries 195, 231, 232-233 355-356, 380-381 Trachea, displacement 48, 63 Tractotomy 79, 378-379 Tracheobronchial injury 355-356, Valvular disruption 358 380-381 Ventricle 373-374 Tracheostomy 59, 470, 636-638 Thoracocentesis 62-63, 646-650 Traction for fractures 67-68, 71, Thoracotomy 159 Anterolateral 364-365 Femur 169-175, 187-188 Approach and instrumentation Lower leg 178 363-364 Pelvis 322 714 Spine 480 Index.qxd 28/09/2004 15:58 Page 715 Index

Transfer - see Aeromedical Management 337-340 evacuation Pathophysiology 337 Transition to war (TTW) 3 Psoas hitch 338 Transposition flap 535, 536 Repair 336-338 Transverse colectomy 273 Ureteric stent 337, 338 "Trauma flap" for head injury 411 Uretero-ureterostomy 339, 340 Trench foot 586-587 Urethral injury Triage 107-113 Aetiology 343 Burns 507, 513, 525 Clinical fatures 343 Compensated/uncompensated Management 344 107-108 Suprapubic catheterisation Definition 107 344-345 Head injury 390-391 Urinary fistula 87, 337 Major incident 609-610, 612 Urinary tract infection 138 Trimethoprim 138 Urological injury 327-346 Tri-Service Anaesthetic Apparatus Bladder 340-342 (TSAA) 557, 566 Pathophysiology 327-330 Tropical diseases Renal trauma 327-337 Abdominal pain 551, 552 Suprapubic catheterisation Amoebic dysentery 549- 551 344-345 Background 539 Testis and scrotum 345-346 Diarrhoea 549-551 Ureter 337-340 Enteric fever 544-546 Urethra 343-345 Fever 540-548 Malaria 540-544 Valvular distruption, after cardiac Pyogenic infections 546-547 injury 358 Pyomyositis 546 Vascular injuries 89, 193-226 Schistosomiasis 547-549 Advanced vascular repair Sickle cell crisis 552 205-211 Surgical considerations 539-540 Anastomosis 206-207 Toxic shock syndrome 547 Anastomotic bleeding, Turning frame 480 control of 204 TWELVE 48 Ankle brachial pressure Tympanic membrane 462, 463, 464 index (ABPI) 198 Anterior tibial artery, Unit Aid Post 112 exposure 224, 225 Ureteric injury 337-340 Arterial spasm 195 Boari flap 338, 339 Arteriography/angiography, Cutaneous ureterostomy on-table 198,199, 204 Interposition, repair of Arteriovenous fistula ureteric defect 340 195-196, 211 715 Index.qxd 28/09/2004 15:58 Page 716 Index

Vascular injuries (cont) End-to-side anastomosis 210 Associated injuries 193 Examination 50-53, 197 Axillary artery, exposure Exposure and control 201, 216-217 212-226 Axillo-femoral graft 210-211 External iliac artery, Back bleeding and inflow, exposure 219-220 management 201-202 Extra-anatomical bypass Brachial artery, exposure 217 210-211 Brachiocephalic artery and False aneurysm 196 vein exposure 212-213 Fasciotomy - see Bypass procedures 210-211 Compartment syndrome Capillary refill time (CRT) 53 Femoral artery, exposure 89, Carotid artery, exposure 89, 220-221 212-214 Femoral vein, exposure 221 Clotting adjuncts 67, 199 Femero-femoral graft 210-211 Common iliac artery, Fogarty catheter 201-202 exposure 219 Haemorrhage 194 Completion angiography 204 Haemorrhage control 65-74 Compressible/ Hepatic artery 86 non- compressible Immediate treatment haemorrhage 65-72, 65-74,199-200 199-200 Incidence 193 Computerised tomography Inferior vena cava 85,88,89 (CT) 199 Internal iliac artery, exposure Consequences of vascular 219 trauma 194-196 Interposition graft 207-208 Covering the vascular Intimal flap 195, 202 repair/anastomosis Investigations 198-199 204-205 Ischaemia 195 Crural vessels, exposure Jugular vein 89 224-226 Long saphenous vein, Definitive vascular surgery exposure 221 techniques 201-211 Long saphenous vein graft Digital subtraction 207-208 angiography (DSA) 199 Lower limb 219-226 Doppler handheld probe 198 Management 197-200 Doppler ultrasound (Duplex ) Mechanisms of injury 194 199 Monitoring, post-operative 211 Drainage 204 Neck 470-472 End-to-end anastomosis Neurological signs after 716 206-207 carotid injury 197 Index.qxd 28/09/2004 15:58 Page 717 Index

P's, the six 197 Inferior vena cava 85, 88, Patch angioplasty 209 89, 305-307 Pathophysiology 194-196 Ligation 89 Peroneal artery, exposure Long saphenous vein graft 225-226 207-208 Popliteal artery and veins, Long saphenous vein, exposure 222-223 exposure 221 Portal vein 89 Management of injury to 205 Posterior tibial artery, Jugular 89, 213-214 exposure 224, 225 Portal 89, 308 Post-operative management Shunt 89 211-212 Venous cannulation 68, 655-656 Profunda femoris artery, Venous cutdown 68, 653-655 exposure 220-221 Venous sinus, head injury 385-386 Pulse oximetry 198 Ventilation - see Breathing and Radial artery exposure 218-219 Ventilation Repair of lacerated vessel 203 Ventilator settings 571-572 Restoration of flow 203-204 Ventilatory support 63-65, 571-572 Root of neck, vascular Ventricle, injury to 373-374 exposure 212-215 Vertical shear (VS) injury 317 Subclavian artery and vein, Vertigo 459, 464 exposure 212-213, Vesicant agents - see Chemical 215-216 Weapons and Blister Agents Synthetic graft 89, 207-208 Vibration, and Aeromedical Thrombectomy 201-202 evacuation 622-623 Thrombosis 195 Violence, psychiatric illness Ulnar artery, exposure 594-595 218-219 Visual acuity 420-421 Upper limb 215-219 Vitreous, injury to 436 Vascular exposure 212-226 VX nerve agent 34 Vascular repairs 100, 201-211 V-Y advancement flap 537 Vascular shunts 80, 89, 207-208 Wallerian degeneration 484 Veins, management of injury Weapons 205 Blast 6 Vertebral arteries, exposure Bullets 1, 3-5, 11-23 215 Fragments 2-5, 11-23 Vascular shunt 80,89, 207-208 Fuel air 2, 502 Vecuronium 558, 560-561, 563 Novel weapons 2 Veins Penetrating 3-5, 11-23 Femoral, exposure 221 Thermal 6, 502 717 Index.qxd 28/09/2004 15:58 Page 718 Index

Weapons (cont) Fasciotomy 96,100, 154-156, Thermobaric 2, 502 164-165, 167-169, "Windswept pelvis" 315 171- 172, 174-177 Wisdom teeth, management of Foreign bodies 102 457-458 Healing 656-658 Working with Aeromedical Immobilisation 69, 96, 100, helicopters 626-627 104, 156-161 World War I 2 Indications for wound World War II 2, 6, 193, 243 inspection 103 Wound Infection, likely bacteriology Abdominal closure 259-260, 138-139 658 Irrigation 97, 103 Amputation 96, 100, 227-242 Langer's lines 99, 658 Antibiotics 96, 97 Length 658 Antipersonnel mine injury Ligaments 100 27, 100, 151, 227-228 Nerves 100, 483-499 Bone 100,101 Open joint wounds 96, 101 Cartilage 101 Optimising healing 528, Chemical contamination 656-657 31-40, 97, 523-525 Retained bullets 103 Closure 90-91, 259-260, Retained fragments 102 656-665 Scalp 96, 397-399 Comparison of civilian and Scrotum 96, 345-346 military wounds 95 Spasm, arterial 195 Complicating factors 95 Splint and elevate 69, 96, Contamination 19-19, 95, 100, 104, 156-161 Coverage 100, 101-102, Superficial fragment wounds 104, 527-538 96, 97 Deep vein thrombosis Surgical handicraft 656-665 prophylaxis 97, 191-192 Degloving injury 97, 99 Xylometazoline 464 Dehiscence 310, 310-311, 656-658 Yersinia pestis 145-146 Delayed primary closure 96, 104, 658 Zygoma, fracture of 443-444, Drains 259, 658, 665 450-451 Dressing 66, 95, 103, 245 Excision 96-101, 658 Exploration 96 Extension 97 718 Face 96, 97, 101, 455-456 Normal_Values.qxd 28/09/2004 15:58 Page AP-I Appendix: Normal vaues Normal Values

Common Biochemical Blood Tests

Investigation Container Min. volume Adult reference (ml) required value

Acid phosphatase Plain 5 Total: <7 U/L Prostatic: <4 U/L

Albumin Heparinized 5 35-51 g/L

Alkaline phosphatase Heparinized 5 30-130 U/L

Amylase Plain 5 <1000 U/L

Aspartate transaminase Heparinized 5 7-40 U/L

Bilirubin Heparinized 5 5-17 µmol/L

Calcium Heparinized 5 2.12-2.55 mmol/L

Cortisol Heparinized 5 170-600 nmol/L

Creatinine Heparinized 5 60-125 µmol/L

Creatinine kinase Heparinized 5 24-190 U/L

Lactic dehydrogenase Heparinized 5 150-450 U/L (LDH)

Sodium (Na+) Heparinized 5 135-145 mmol/L

Potassium (K+) Heparinized 5 3.5-5.0 mmol/L

Glucose Fluoride oxalate 4 3-5 mmol/L (fasting)

Gamma glutamyl Heparinized 5 Male: <50 U/L transferase (GGT) Female: <32 U/L

Iron Plain 10 9-29 µmol/L

Thyroxine Plain 5 50-150 nmol/L

TSH Plain 5 0.5-6.5 mU/L

Free T3 Plain 5 2.9-8.9 pmol/L

Total protein Heparinized 5 60-80 g/L

AP-I Normal_Values.qxd 28/09/2004 15:58 Page AP-II Appendix: Normal vaues Arterial Blood Gases (ABGs)

Send 2.5 ml in a lightly heparinized syringe

pH 7.35-7.45

PCO2 35-45 mmHg

PO2 90-110 mmHg

Bicarbonate 22-27 mmol/l

Base excess -3 to +3 mmol/l

Haematological Values (FBC)

Send 5ml in pink EDTA tube

Erythrocyte sedimentation rate (ESR) <20

Haemoglobin (HB) Male: 13-18 g/dl Female: 11.5-16.5 g/dl

White blood cell count (WBC) 4-11.0 x 109/l

Mean corpuscular haemoglobin (MCH) 27-32 pg/l

Mean corpuscular haemoglobin concentration (MCHC) 30-35 g/dl

Mean corpuscular volume (MCV) 78-98 ft

Packed cell volume (PCV) or haematocrit Male: 0.40-0.54 Female: 0.35-0.47

Platelets 150-400 x 109/l

Prothrombin time (PT) 11-15 s

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