Disease Processes and Diagnostic Techniques 1

Disease processes and diagnostic techniques 1 1. Surgery and the mechanisms of surgical disease 3 DISEASE PROCESSES 2. Managing physiological change in the surgical patient 9 3. Immunity, infl ammation and infection 27 4. Shock and resuscitation 52 DIAGNOSTIC TECHNIQUES 5. Imaging and interventional techniques in surgery 59 6. Screening for adult disease 88 CCh001-F10345.inddh001-F10345.indd 1 55/7/2007/7/2007 44:05:47:05:47 PPMM CCh001-F10345.inddh001-F10345.indd 2 55/7/2007/7/2007 44:05:47:05:47 PPMM Surgery and the mechanisms of surgical disease 1 A SHORT HISTORY OF SURGERY ................................................ 3 PRINCIPAL MECHANISMS OF SURGICAL DISEASE .................... 5 Congenital conditions ..................................................................................... 5 APPROACHES TO SURGICAL PROBLEMS ................................... 4 Acquired conditions ......................................................................................... 6 A SHORT HISTORY OF SURGERY There can be no doubt that the fi rst surgeons were the The fi rst scientifi c departure from this barbaric treat- men and women who bound up the lacerations, contu- ment was taken by the great French military surgeon sions, fractures, impalements and eviscerations to which Ambroise Paré (1510–1590) who, while still a young man, man has been subject since he appeared on Earth. Since revolutionised the treatment of wounds by using only man is the most vicious of all creatures, many of these simple dressings, abandoning cautery and introducing injuries were infl icted by man upon man. Indeed, the ligatures to control haemorrhage. He established that his battlefi eld has always been a training ground for surgery. results were much better than could be achieved by the Right up to the 15th century, surgeons dealing with old methods. trauma were surprisingly effi cient. They knew their Ignorance of the basic sciences behind the practice limitations—they could splint fractures, reduce disloca- of surgery was slowly overcome. The publications of tions and bind up lacerations, but were only too aware The Fabric of the Human Body in 1543 by Andreas Ves- that open wounds of the skull, chest and abdomen were alius (1514–1564) and of The Motion of the Heart by lethal and were best left alone, as were wounds involving William Harvey (1578–1657) in 1628 were two notable major blood vessels or spinal injuries with paralysis. They landmarks. observed that wounds would usually discharge yellow Surgical progress however was still limited by two pus for a time; indeed this was regarded as a good prog- major obstacles. First, the agony of the knife: patients nostic sign and was labelled ‘laudable pus’. would only be prepared to undergo an operation to relieve The 15th century heralded a new and dreaded pathol- intolerable suffering (for example from a gangrenous ogy—the gunshot wound. These injuries would stink, limb, a bladder stone or a strangulated rupture) and, of swell and bubble with gas. There was profound systemic course, the surgeon needed to operate at lightning speed. toxicity and a high mortality. Of course, we now know Second, there was the inevitability of suppuration, with that this was the result of clostridial infection of wounds its prolonged disability and high mortality, which was with the extensive anaerobic tissue damage caused by often as high as 50% after amputation. Amazingly, both shot and shell. The surgeons of those times were shrewd these barriers were overcome within a couple of decades clinical observers but they surmised that these malign of each other. effects were due to gunpowder acting as a poison, for it In 1846, William Morton (1819–1868), a dentist was not until centuries later that the bacterial basis of working in Boston, Massachusetts, introduced the use of wound infection began to be understood. At that period ether as a general anaesthetic. This was followed a year the remedy was to destroy the poison with boiling oil or later by chloroform, employed by James Young Simpson cautery. Boiling oil was the more popular since it was (1811–1870) in Edinburgh, mainly in midwifery. These advocated by the Italian surgeon Giovanni da Vigo (1460– agents were taken up with immense enthusiasm across 1525), the author of the standard text of the day, Practica the world in a matter of weeks. In Arte Chirurgica Compendiosa. These treatments not only The work of the French chemist Louis Pasteur (1822– produced intense pain but also made matters worse by 1895) demonstrated the link between wound suppuration increasing the amount of tissue necrosis. and microbes. This led Joseph Lister (1827–1912), who 3 CCh001-F10345.inddh001-F10345.indd 3 55/7/2007/7/2007 44:05:47:05:47 PPMM 1 DISEASE PROCESSES AND DIAGNOSTIC TECHNIQUES was then a young professor of surgery in Edinburgh, to So at last, in the 1870s, the scene was set for the coming perform the fi rst operation under sterile conditions in enormous advances in every branch of surgery whose 1865. This was treatment of a compound fracture of the breadth and successes form the basis of this book. tibia in which crude carbolic acid was used as an antiseptic. The development of antiseptic surgery and, later, Prof. Harold Ellis CBE MCh FRCS modern aseptic surgery progressed from there. APPROACHES TO SURGICAL PROBLEMS What do surgeons do? cal trials, continue to broaden as equipment and skills become increasingly sophisticated. Surgeons are doctors who do operations, i.e. cutting tissue to treat disease, the patient usually being under some What sort of patients come to surgeons? form of anaesthesia. However, the range of work individ- ual surgeons undertake varies widely, depending on the Different types of surgeon practise in very different ways, culture in which they work and the resources avail- depending on their specialty and their level of responsi- able, the nature and breadth of their specialisation, what bility for emergency work. In the UK, most patients are other specialists are available, and the local needs. The referred to surgeons by another doctor, e.g. family practi- principles of surgery—access, dissection, haemostasis, tioner, accident and emergency (ER) offi cer or internal repair, reconstruction, preservation of vital structures and physician. The exceptions include patients suffering closure—are similar in all specialties. trauma who self-refer or are brought to a hospital by A general surgeon usually means one who principally ambulance. In some other countries, patients are able to undertakes general surgical emergency work and elective self-refer to the specialist they feel is most appropriate. abdominal gastrointestinal (GI) surgery. In geographi- Regardless of the route of referral, surgical patients fall cally isolated areas and regions where resources are scarce, into the following categories: such a surgeon might also undertake some gynaecology, ● Emergency/acute, i.e. symptoms lasting minutes to urology, paediatric surgery, orthopaedic and trauma hours or up to a day or two—often obviously surgery and perhaps basic ear, nose and throat (ENT) surgical conditions such as traumatic wounds, and ophthalmology, and even obstetrics. Conversely, fractures, abscesses, acute severe abdominal pain or in developed countries, there is an increasing trend gastrointestinal bleeding towards greater specialisation. Gastrointestinal surgery, ● Intermediate urgency—usually referrals from other for example, is often divided into ‘upper’ and ‘lower’ GI doctors based on suspicious symptoms and signs and surgery, and upper GI surgery itself may further divide sometimes investigations, e.g. suspected colonic into the subspecialties of hepatobiliary, laparoscopic, cancer, gallstones, renal or ureteric stones pancreatic and gastro-oesophageal cancer surgery. ● Chronic conditions likely to need surgery, e.g. Surgeons should not be thought of simply as ‘cutting varicose veins, hernias, arthritic joints, cardiac and sewing’ doctors. The perceived drama of surgery may ischaemia or rectal prolapse be superfi cially attractive but good surgery is rarely dramatic. Only when things go wrong does the drama The diagnostic process increase, and this is often not comfortable. Surgery is an art or craft as well as a science, and judgement, coping In order to manage surgical patients appropriately, a under pressure, taking decisive action when necessary, working diagnosis needs to be formulated to guide teaching and training skills and people management whether investigations are necessary and if so, their type skills are essential qualities. Operating skills can be learnt and urgency, and to determine what intervention (i.e. by most people, but the skills involved in deciding when treatment) is necessary. The process initially depends it is in the patient’s best interests to operate are absolutely upon whether immediate life-saving intervention is essential and must also be actively learnt and practised. required or, if not, the perceived urgency of the case. For Surgeons also play an important role in the diagnostic example, a patient bleeding from a stab wound might process, using both clinical skills and appropriate inves- need pressure applied to the wound immediately whilst tigations as part of their armamentarium. In this context, resuscitation and detailed assessment are carried out. At many surgeons undertake various forms of diagnostic the other end of the scale, if the symptoms suggest the and therapeutic endoscopy. These include gastroscopy, patient has a rectal carcinoma, a systematic

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