J R Army Med Corps 2003; 149: 255-259 J R Army Med Corps: first published as 10.1136/jramc-149-04-02 on 1 December 2003. Downloaded from

ORIGINAL PAPERS

Consensus Statement On The Early Management Of Crush And Prevention Of Crush Syndrome

I Greaves, K Porter, JE Smith

ABSTRACT cause the syndrome is incompatible with life Crush Syndrome remains rare in due to the inherent internal organ damage, European practice. It is however comm- but there are a few reported cases of such on in areas of civil disorder and where instances (3). the normal structures of society have Crush syndrome bears many similarities given way to civil war or natural to, but is distinct from, the syndrome caused disaster. Western Doctors are becoming by heat illness. increasingly involved in such situations and there is no reason to believe that Definition instances due to more conventional Following a search of the literature, it was felt causes, such as collapse in the elderly or that a definition of and crush road traffic accidents will cease. For all syndrome was required. these reasons it is important that clini- Consensus view cians who deal infrequently with crush “A crush injury is a direct injury resulting from syndrome have access to appropriate crush. Crush syndrome is the systemic guidelines. This consensus report seeks manifestation of muscle cell damage resulting to provide such advice. from pressure or crushing”. The severity of the condition is related to Key Words: Crush Syndrome, Renal Failure, the magnitude and duration of the com- Natural Disasters. pressing force, and the bulk of muscle aff- ected. The definition is not, however, dep- Introduction endent on the duration of the force applied. Crush and crush syndrome were first Examples of this relationship are firstly a described in the English Language literature patient whose legs are run over by the wheels by Bywaters and Beall in 1941 (1), after of a truck. In this case the force is large, but the duration is very short. At the other

several patients who had been trapped under http://militaryhealth.bmj.com/ rubble of buildings bombed in the Blitz extreme, there is the elderly patient who has subsequently died of acute renal failure. It suffered a stroke, falls, and lies in the same has been described in numerous settings position for hours, sustaining a crush injury since, most commonly after natural disasters to the areas of the body on which they are such as earthquakes, in war, and after lying. In this case, the force is relatively small, buildings have collapsed as a result of ex- but crush syndrome may develop as a result Lt Col I Greaves plosion. Crush syndrome is also seen foll- of the prolonged period of pressure. Similar RAMC owing industrial incidents such as mining cases to this are described as a result of drug overdose (4). Visiting Professor of accidents and road traffic accidents. How- ever, crush syndrome is not confined to Education Centre, traumatic aetiologies, and has also been Pathogenesis and clinical on September 27, 2021 by guest. Protected copyright. The James Cook described following periods of crush by features University Hospital, patients’ own body weight, after stroke or The typical clinical features of crush syn- Marton Road, intoxication (2). drome are predominantly a result of Middlesbrough, Most commonly in traumatic crush, the traumatic and subsequent TS4 3BW legs are affected, and less frequently the release of muscle cell contents. The mech- arms. Many authors believe that crush injury K Porter anism behind this in crush syndrome is the of the head and torso significant enough to leakiness of the sarcolemmal membrane Consultant Trauma This paper reports the findings of a consensus meeting on Crush Injury and Crush Syndrome held in Surgeon, University Birmingham on 31 May 2001, and co-ordinated by the Faculty of Pre-Hospital Care of the Royal Hospital, Birmingham College of Surgeons of Edinburgh. Surg Lt Cdr JE Smith MBBS MSc MRCP RN Organisations represented The Voluntary Aid Societies The Royal College of Physicians Specialist Registrar in Emergency Medicine The Ambulance Service Association The Royal College of Surgeons of Edinburgh Defence Medical The British Association for Immediate Care The Intensive Care Society Services, British Association for Emergency Medicine The Royal College of Nursing Derriford MDHU, Faculty of Accident and Emergency Medicine The Military Plymouth, PL6 8DH. The Royal College of Anaesthetists The Faculty of Pre-hospital Care 256 Consensus Statement On Crush Injury J R Army Med Corps: first published as 10.1136/jramc-149-04-02 on 1 December 2003. Downloaded from

caused by pressure or stretching. As the Airway, Breathing and Circulation is the next sarcolemmal membrane is stretched, sod- priority. Attention must be given in trauma to ium, calcium and water leak into the the possibility of spinal injury and full spinal sarcoplasm, trapping extracellular fluid precautions should be maintained. Admin- inside the muscle cells. In addition to the istration of high flow oxygen by mask should influx of these elements into the cell, the cell be a priority in treatment, as should the releases potassium and other toxic arrest of any obvious external haemorrhage substances such as , phosphate and the splinting of limb injuries.The patient and urate into the circulation (5). should be exposed as necessary to assess and The end result of these events is manage injuries. In a hostile environment, or (discussed below), hyperkalaemia (which where there is a risk of hypothermia, may precipitate cardiac arrest), hypocalc- exposure should be as limited as possible. aemia, metabolic , compartment Assessment of distal neurovascular status is syndrome (due to compartment swelling), essential if exposure is to be kept to a and acute renal failure (ARF). The ARF is minimum. due to a combination of hypovolaemia with The patient should be released as quickly subsequent renal vasoconstriction, metabolic as possible, irrespective of the length of time acidosis and the insult of nephrotoxic trapped. substances such as myoglobin, urate and phosphate. Fluid Once the initial primary survey has been Shock performed, intravenous access should be Haemodynamic instability secondary to obtained. If limb crush injury has occurred, crush syndrome is multi-factorial. Firstly, and there is a likelihood of the patient many patients have other injuries, such as developing crush syndrome, the following fractures of the pelvis or lower limbs, fluid guidelines should be followed. In the sufficient in themselves to cause hypovol- presence of life-threatening thoraco- aemia. The sequestration of fluid into the abdominal injury, fluid resuscitation should affected muscle compartments has already be performed according to the Faculty’s been described, resulting in fluid shift from previously published guidelines (8). the intravascular to the intracellular comp- artments. This may cause hypovolaemia, as Consensus view the intravascular volume is depleted. Elec- An initial fluid bolus of 2 litres of crystalloid trolyte imbalances such as hyperkalaemia, should be given intravenously.This should be hypocalcaemia and a metabolic acidosis will followed by 1-1.5 litres per hour.The fluid of have a negatively inotropic effect, and there is choice is normal , warmed if possible,

also evidence that there is direct myocardial as this is established as the fluid carried by http://militaryhealth.bmj.com/ depression from other factors released when the majority of pre-hospital vehicles in the muscle cells are damaged (6). United Kingdom. Hartmann’s solution contains potassium and has a theoretical Approach to treatment disadvantage of exacerbating hyperkalaemia. Treatment of the crushed patient can be If possible, fluid should be started prior to divided into two phases. The initial pre- extrication, however, gaining intravenous hospital phase may, depending on the access and the administration of fluid should mechanism of injury, involve a prolonged not delay extrication and transport to a extrication period.The second phase comm- definitive care facility. Early catheterisation ences on reaching a definitive medical care should be considered, especially if there is a facility. In the case of prolonged on-scene prolonged extrication or evacuation phase. on September 27, 2021 by guest. Protected copyright. time, or delay in transfer due to geographical Once the patient reaches hospital, 5% reasons, some of the second phase guidelines dextrose should be alternated with normal may be employed in the pre-hospital saline to reduce the potential sodium load. environment. Analgesia Consensus view Consensus view Safety is the first priority when approaching The use of medical teams including an accident scene, and this is particularly paramedics, nurses and doctors should be relevant to situations where patients may considered at an early stage, and appropriate have suffered crush injuries, as there may be analgesia should be given. This may involve danger from falling debris or risk of further the use of Entonox® initially, but most building collapse. patients will require intravenous analgesia Once the scene has been declared safe, in such as an opiate, titrated against response. cases of mass casualties, a system (such The use of ketamine, with or without the as the triage sieve – Major Incident Medical concomitant use of a benzodiazepine, is also Management & Support (MIMMS) (7)) an effective means of relieving pain, and may should be used to prioritise casualties and aid extrication. assess the need for further treatment. For First responders may give oral analgesia in each individual casualty, an assessment of the absence of senior clinical support. I Greaves, K Porter, JE Smith 257 J R Army Med Corps: first published as 10.1136/jramc-149-04-02 on 1 December 2003. Downloaded from

Triage use of a solute alkaline diuresis is accepted to Consensus view be protective against the development of Patients with crush injuries should be taken acute renal failure (11,12). to a hospital with an intensive care facility and the equipment and expertise necessary Consensus view to provide renal support therapy such as It is recommended that urine pH is haemofiltration or dialysis. measured, and kept above 6.5 by adding 50mmol aliquots of bicarbonate (50mls Tourniquets 8.4% sodium bicarbonate) to the The use of tourniquets has a theoretical role intravenous fluid regime. Solute diuresis is in the management of these patients. If the affected by administering at a dose release into the circulation of the contents of of 1-2g/kg over the first four hours as a 20% crushed muscle cells can be avoided, solution, and further mannitol should be possibly with the use of a tourniquet, it may given to maintain a urine output of at least 8 be of benefit. However, there is currently no litres per day (300mls per hour). Fluid available evidence to support this. requirements are high, usually of the order of 12 litres per day, due to the sequestration of Consensus view fluid in muscle tissue. Fluid should be given The use of tourniquets should be reserved at approximately 500 mls/hour, but regular for otherwise uncontrollable life threatening review of clinical parameters such as central haemorrhage. There is no evidence at the venous pressure and urine output should moment to support the use of tourniquets in dictate exact amounts of fluid given. the prevention of The maximum daily dose of mannitol is following extrication, or in the prevention of 200g, and it should not be given to patients washing of the products of rhabdomyolysis who are in established anuria. into the circulation. Children Consensus view Another theoretically advantageous measure There is very little evidence in the literature is amputation of a crushed limb to prevent to guide the treatment of children suffering crush syndrome. from crush injuries. In young children the difference in body proportions, namely the Consensus view reduced contribution to the total percentage There is no evidence to support the use of made by the limbs, may influence the amputation as a prophylactic measure to incidence of crush syndrome. The fluid prevent crush syndrome. Reports from the resuscitation guidelines from Advanced literature suggest that even severely crushed Paediatric Life Support (APLS) (13) of an http://militaryhealth.bmj.com/ limbs can recover to full function. If the limb initial bolus of 20mls per kg should be is literally hanging on by a thread, or if the followed in these patients. patient’s survival is in danger due to entrapment by a limb, amputation should be The elderly and patients with co- considered and appropriate expert advice morbidity sought. Consensus view In the elderly, and those with pre-existing Immediate in-hospital care medical conditions such as cardiac failure, Consensus view fluid replacement must be tailored to Patients should be assessed following normal requirements and given with caution. Close on September 27, 2021 by guest. Protected copyright. Advanced Trauma Life Support (ATLS) monitoring of the clinical state of the patient, guidelines (9). Baseline blood tests should and regular review of fluid requirements is be taken.These will include full blood count, essential in these patients. urea and electrolytes, creatinine kinase, amylase, liver function tests, clotting screen and group and save (cross match if deemed The development of compartment appropriate). The patient should be syndrome in crush injury is due to the catheterised and hourly urine measurements uptake of fluid into damaged muscle tissue commenced. Central venous pressure and contained within the restricted compart- invasive arterial monitoring should be ment. Once compartment pressure exceeds considered. capillary perfusion pressure at about 30 - 40mm Hg, the tissue inside the The use of solute-alkaline compartment becomes ischaemic, and diuresis compartment syndrome develops. The development of acute renal failure in The traditional treatment of compartment these patients significantly decreases the syndrome is fasciotomy (4), but there is now chances of survival (10). Every effort must evidence that initial treatment with mannitol be made, therefore, to prevent its may decompress compartment syndrome occurrence. Alkalinisation of urine and the and avoid the need for surgery (5,12). 258 Consensus Statement On Crush Injury J R Army Med Corps: first published as 10.1136/jramc-149-04-02 on 1 December 2003. Downloaded from

Consensus view to the increased ischaemia times involved in In patients with compartment syndrome due application of a tourniquet? to crush injury, in the absence of neuro- Could cooling the limb be used in order to vascular compromise, a trial of mannitol slow cellular respiration and consequently therapy should be instigated, but a specialist decrease oedema, compartment syndrome opinion should be sought early. and improve limb viability? Tourniquet effectiveness was highlighted Hyperbaric oxygen therapy as a potential shortfall in their use.There is a There is theoretical and limited experimental requirement to perform a literature search evidence that hyperbaric oxygen therapy may into tourniquet usage, in particular regarding improve and reduce the need their use in Biers blocks, in order to for multiple surgical procedures in crush determine the effectiveness of certain types injury (14). of tourniquet and the leakage rates of drugs, High concentrations of O2 cause systemic past the tourniquet. This may assist in vasoconstriction but continue to deliver establishing the likelihood of potassium adequate O2 delivery. In a similar fashion, leaking into the systemic circulation. nitric oxide synthase inhibitors may also have a role in preventing excessive vasodilatation Fluid administration in the crushed muscle and the consequent Types of fluid currently used for admini- increase in third space fluid losses (15). stration include: normal saline, Hartmann's, Dextran or starches. What is the correct Consensus view amount of fluid to be giving? Should we be Logistically hyperbaric oxygen treatment has looking at urine output, absolute volume limited application. Patients with no sig- intake or acidity of urine as a guide to fluid nificant co-morbidity, and who can be man- administration? Oedema occurring is aged in a hyperbaric chamber where the fac- secondary to massive fluid administration ility is available, may be treated with hyper- and may be detrimental. At what stage do we baric oxygen therapy. It is recommended that need to worry about this? What effect does treatment options are discussed with the this have on compartment syndrome? local hyperbaric unit. This is not recomm- ended as first line treatment. Patients should, Prognostic indicators however, receive high flow oxygen, unless Creatinine kinase, myoglobinaemia and amy- there is a specific contra-indication. lase have been suggested as prognostic indicators, although it is not clear that they can predict outcome at an early enough stage Further management to allow effective intervention. The use of Consensus view

microalbuminuria as a prognostic indicator http://militaryhealth.bmj.com/ In many cases, intensive care support will be of crush syndrome was suggested. required for the complications of crush syndrome. If the patient becomes oligo- or Hyperbaric oxygen therapy anuric, it is likely that they will require Use of the Institute of Naval Medicine was haemofiltration or dialysis. suggested in order to evaluate the merits of this treatment modality. In view of the Multiple casualties scarcity of this resource around the country it Consensus view did not meet with a great deal of support. In the civilian environment in the United Kingdom, there will be a huge strain on Bicarbonate administration intensive care facilities if there are multiple Early administration of bicarbonate intra- on September 27, 2021 by guest. Protected copyright. crushed casualties. A policy should be drawn venously is thought to decrease metabolic up to prepare for the dispersal of these acidosis and promote alkalisation of urine casualties on both a National and Inter- which decreases the precipitation of myo- national level should an incident occur. globin in the renal tubules. Administration of Further information is available in Better’s bicarbonate immediately post-extrication, in review of 1999 (5). anticipated metabolic acidosis, was dis- cussed. Has this been shown to be beneficial? Areas identified for future Are there any detrimental features? What research would be the appropriate and safe doses to Use of tourniquets use? Is there a role for the combined use of Is there a role for the tourniquet post or pre acetazolamide in order to prevent metabolic extrication of the crush injury casualty? The alkalosis following bicarbonate admini- use of an animal model of crush injury was stration? suggested, to assess the suitability of tourniquet administration. Comparison of Mannitol and compartment syndrome tourniquet placement versus no tourniquet There is anecdotal evidence in the literature in delayed intravenous fluid administration that due to the high rate in was suggested as a further research option. performing fasciotomy for compartment Are there any further deleterious effects due syndrome in crushed patients, they are best I Greaves, K Porter, JE Smith 259 J R Army Med Corps: first published as 10.1136/jramc-149-04-02 on 1 December 2003. Downloaded from

managed with mannitol alone. It is suggested suffering from the crush sydrome after mass that there is a noticeable difference in dia- disasters. Mil Med 1999; 164: 366-9. meter and symptoms of the lower leg within 6. Rawlins M, Gullichsen E, Kuttila K, Peltola O, Niinikoski J. Central hemodynamic changes in 40 minutes of administration of IV mannitol experimental muscle crush injury in pigs. Eur Surg (5). Fasciotomy should be reserved for Res 1999; 31: 9-18. refractory cases. The use of an animal model 7. Major Incident Medical Management & Support of a compartment syndrome is questioned (MIMMS) 2002. BMJ Bookshops, London. due to the anatomical differences from hum- 8. Greaves I, Porter KM, Revell MP. Fluid ans. Many animals that are commonly used Resuscitation in Pre-Hospital Trauma Care: A Consensus View. J.R. Coll. Surg. Edinb. 47; 2;451- as models for humans, such as pigs, sheep 457. and dogs do not have fascial compartments. 9. Advanced Trauma Life Support for Doctors. Primates share similarities but, ethically, American College of Surgeons 1997 Chicago. would be more difficult to justify. Further 10. Ward MM. Factors predictive of acute renal failure information on existing animal experiment- in rhabdomyolysis. Arch Intern Med 1988; 148: 1553-1557. ation relating to compartment syndrome is 11. Better OS. The crush syndrome revisited (1940- required prior to planning any further 1990). Nephron 1990; 55: 97-103. projects. 12. Better OS, Zinman C, Reis ND et al. Hypertonic mannitol ameliorates intracompartmental References tamponade in model compartment syndrome in 1. Bywaters EGL, Beall D. Crush injuries with the dog. Nephron 1991; 58: 344-6. impairment of renal function. BMJ 1941; 1: 427. 13. Advanced Paediatric Life Support 2nd Edition 2. Michaelson M. Crush injury and crush syndrome. 2001. BMJ Bookshops. World J Surg 1992; 16: 899-903. 14. Bouachour G, Cronier P, Gouello JP,Toulemonde 3. Hiraide A, Ohnishi M, Tanaka H et al. Abdominal JL,Talha A, Alquier P. Hyperbaric Oxygen therapy and lower extremity crush syndrome. Injury 1997; in the management of crush injuries; a randomized 28(9-10): 685-6. double-blind placebo-controlled clinical trial. J 4. Shaw AD, Sjolin SU, McQueen MM. Crush Trauma 1996; 41(2): 333-9. syndrome following unconsciousness: need for 15. Rubinstein I, Abassi Z, Coleman R, Milman F, urgent orthopaedic referral. BMJ 1994; 309: 857- Winaver J, Better OS. Involvement of nitric oxide 9. system in experimental muscle crush injury. J Clin 5. Better OS. Rescue and salvage of casualties Invest 1998; 101(6): 1325-33. http://militaryhealth.bmj.com/ on September 27, 2021 by guest. Protected copyright.