(i) Initial resuscitation of the trauma victim

Tourniquets 

Tourniquets are regularly used during transport from the scene of injury to the care facility in the military setting. In situations where haemorrhage control cannot be obtained with direct pressure, the application of a proximal tourniquet can be an effective method of haemorrhage control. The aim of tourniquet use in the pre-hospital setting is to control haemorrhage until the bleeding can be controlled in hospital, usually by surgical intervention. In the military setting, tourniquets are used with success in severely injured patients with major extremity vascular injury or traumatic amputation. A study by Beekley et al1 found that there was improved haemorrhage control in the above two patient groups and that tourniquet use (mean time 70 min) was not associated with neurological deficit or other adverse sequelae.

Fluid resuscitation 

Previously, the initial management of hypovolaemia in the trauma patient involved the rapid administration of 2000 ml of Ringer's lactate as an initial fluid challenge. More recently, there have been changes in practice such that the initial fluid resuscitation of the patient is gauged by palpation of the radial pulse. Fluid boluses of up to 250 ml are given to maintain the radial pulse, as required. In general, the radial pulse is palpable when the systolic blood pressure is >70 mmHg, which is sufficient to maintain cerebral and myocardial perfusion in the short term. This is referred to as hypotensive resuscitation, or permissive hypotension, and is one of the components of damage control resuscitation. The use of small volumes of fluid avoids haemodilution and reduces the risk of coagulopathy. A lower systolic blood pressure will allow primary blood clots to form more easily and reduces the risk of secondary haemorrhage if the blood pressure rises before surgical control of the source of haemorrhage is obtained.

Pelvic binders 

In trauma victims sustaining blunt trauma, bleeding from pelvic fractures can be difficult to evaluate clinically. The practice of testing pelvic stability for pelvic fractures has a low sensitivity and specificity and has the potential to increase bleeding by disrupting blood clots. It should not be performed. Splintage of unstable fractures reduces pain, decreases bleeding and prevents further soft tissue injury from movement of the fracture. It is now recommended that pelvic fractures, as well as long-bone fractures, are splinted prior to transport. For the pelvis, commercially available circumferential splints (pelvic binders) are now recommended pre-hospital for patients suspected to have severe pelvic fractures.

Rapid transfer to major trauma centres 

In England and Wales, regional trauma networks are being developed and the first will become operational in London in April 2010. These networks of hospitals will work to agreed protocols with a hub and spoke system of Trauma Units, with peripheral District General Hospitals and a single, central, designated Major Trauma Centre. In many cases, triage criteria will allow direct transfer of the severely injured patient from the accident to the Major Trauma Centre, bypassing peripheral hospitals en route. Experience in other countries has shown that the development of Trauma Centres can reduce the mortality from trauma by 20% within the local population. However, the development of a Regional Trauma Network is more effective and reduces mortality by up to 40%. Multiple trauma is uncommon, with an incidence of about 1 per 10 000 urban population per year. The best outcome, in terms of mortality and morbidity, is achieved in specialist units that treat 500 or more patients with an injury severity score (ISS) of >15 per year. Thus it is likely that each regional network will require one Major Trauma Centre (providing all specialties on one site), per 5 million population.

Primary survey2 A – Airway maintenance with spine protection 

This involves assessment of the trauma victim's airway looking for causes of obstruction, such as foreign bodies, and identifying fractures, soft tissue injuries and burns that may subsequently lead to airway obstruction. The airway must always be protected in patients with reduced level of consciousness.

Whilst assessing the trauma victim's airway, the spine requires immobilization and protection. For the cervical spine, this may be by inline traction or by triple immobilization with collar, sandbags and tape. For the thoracic and lumbar spine, patients are initially immobilized on a spine board and movement of the spine avoided.

B – Breathing and ventilation 

The assessment of breathing involves looking at the three key areas that are necessary for proper ventilation: the lungs, the chest wall and the diaphragm. Injuries to any of these can lead to impaired breathing and ventilation. Injuries that may be identified during this assessment include tension pneumothorax, flail chest with pulmonary contusions, massive haemothorax and open pneumothorax.

C – Circulation with haemorrhage control 

Hypotension in the trauma victim should always be assumed to be due to bleeding until proven otherwise. A rapid clinical assessment of the patient's haemodynamic status can be performed by observing the level of consciousness, skin colour and the pulse rate. Whilst assessing the trauma victim's haemodynamic status, control of haemorrhage should also be performed. External bleeding can be controlled by direct pressure but severe limb bleeding, for example that associated with blast injury, may best be controlled by rapid application of a tourniquet.

Severe pelvic fractures may result in massive, life-threatening haemorrhage. All movement of the pelvis should be avoided, as this can disrupt any blood clot that has formed and result in increased haemorrhage, which may be catastrophic. We recommend the rapid application of a pelvic binder in all victims of blunt trauma who have a reduction in systolic blood pressure (<110 mmHg). Examination for pelvic stability should not be performed. It provides no clinically useful information, is painful and potentially harmful. We would also recommend that the patient is not log-rolled (to examine the spine) until the pelvis has been cleared with a normal pelvic X-ray. An exception to the rule may be the victim of blast injuries where an early log roll may be necessary to identify penetrating, posterior wounds.

The use of pelvic binders has become more common in emergency departments when managing patients with suspected pelvic fractures. A study by Croce et al3 compared their use with that of external pelvic fixation in patients with life-threatening pelvic fractures and found that the number of units of blood transfused at both 24 and 48 h was significantly reduced in patients with the binder. This may have been due to the fact that external fixators take more time to apply, thus allowing further bleeding, whereas the pelvic binder is quick to apply, splints the pelvis circumferentially and reduces the pelvic volume. Pelvic binders in this situation are useful intermediary devices before definitive internal fixation of unstable pelvic fractures. There is no evidence that they increase damage in patients with lateral compression injuries. There are sporadic reports of pressure sores after their prolonged application and most authors recommend that they are released within 24–48 h of application, once the patient is haemodynamically stable.

D – Disability 

A rapid assessment of the trauma victim's neurological status involves evaluation of the consciousness level (utilizing Glasgow Coma Score (GCS)), assessment of pupils and spinal cord injuries. A GCS below 8 must alert the attending physician to potential for airway compromise.

E – Exposure/environmental control 

Assessment of the trauma victim requires full exposure of the patient in order to fully identify all injuries. During this stage, it is imperative that a reduction in body temperature is prevented by using external warming devices and warmed intravenous fluids.

During the primary survey, X-rays of the chest and pelvis should be obtained rapidly to identify potentially life-threatening injuries that cannot be reliably diagnosed by clinical examination.

Secondary survey2 

The secondary survey consists of a head-to-toe evaluation of the patient to identify other injuries and guide further imaging. Modalities of imaging such as CT, ultrasound, echocardiogram or angiography may take place as part of the secondary survey in an attempt to identify injuries sustained.

Identification of source of bleeding 

FAST scan (focused abdominal sonography for trauma): the use of ultrasound in the assessment of trauma victims started in Europe in the 1970s and since then, techniques have gradually improved. FAST scanning is a limited ultrasound scan of the trauma patient that takes place in the emergency room, as an adjunct to the primary survey. The FAST scan is used to look for the presence of free fluid in four regions; pericardium, perihepatic and hepato-renal space, perisplenic region and pelvis. It is useful for looking for free fluid. However, it is not accurate for identifying solid organ or bowel injuries. It provides a rapid assessment of the trauma victim: if there is free intraperitoneal fluid and the patient is haemodynamically unstable despite resuscitation, then it can lead to earlier laparotomy for haemorrhage control. A study by Rozycki et al4 looked at the use of FAST scan in 1540 patients (1227 blunt trauma, 313 penetrating injuries) and found an overall sensitivity of 83.3% and specificity of 99.3%. When evaluating patients with precordial or transthoracic wounds, FAST scans had a sensitivity of 100% and specificity of 99.3%, and for hypotensive patients who had sustained blunt abdominal trauma, FAST scans had a sensitivity and specificity of 100%.

Computed tomography (CT): the use of CT scanning in the management of the trauma victim is becoming more prevalent and is the imaging modality of choice for the haemodynamically stable patient. The time it takes to perform CT scans in trauma victims has decreased dramatically, firstly due to the development of faster scanners and secondly due to the location of the CT scanners within or close to most large emergency departments.

CT scan for severe trauma should routinely use intravenous contrast and scan the patient from vertex to symphysis pubis. This allows the rapid identification of most significant head, spinal, thoracic, abdominal and pelvic injuries. This type of scan provides so much useful information in planning the immediate management of polytrauma, that many trauma centre protocols have changed to allow CT scans in patients with hypotension. It is essential that the trauma team accompanies the patient to the scanner, and in these circumstances, many departments will “routinely” scan patients with a systolic blood pressure of 70 mmHg or more. However, the CT suite is not the safest environment. The scan must be performed rapidly and the patient transferred to a place of safety as quickly as possible. Patients in extremis with a systolic blood pressure <70 mmHg should not be transferred to a CT suite, but a scan may be performed in departments that have a CT scanner in the emergency department.

In the context of the haemodynamically unstable patient who has sustained blunt trauma, the initial investigation in the emergency department is a FAST scan to localize free fluid, as outlined above. However, in the haemodynamically stable patient use of CT is more appropriate. With the use of contrast-enhanced CT scanning, the ability to localize the site of contrast extravasation has been very important in the management of patients sustaining blunt abdominal trauma. Yao et al5 looked at blunt abdominal trauma in 547 clinically stable patients and found that CT isolated a source of bleeding in 18% of the patients. This is important with regards to the treatment options of surgery, angiographic embolization or observation alone. CT is also useful for evaluation of the retroperitoneum. However, it is less sensitive for detection of injuries to hollow viscera.6

Pelvic angiography: for severe pelvic fractures, 90% of bleeding is related to venous injury and only 10% is due to arterial injury. However, the majority of unstable patients have arterial bleeding.7 In patients with venous bleeding, the bleeding may stop once the pressure within the retroperitoneal space and the venous pressure equalize. If the pelvic fracture is not reduced however, this can lead to enlargement of the retroperitoneal space and hence greater blood loss.7 Studies analyzing the success rate of angiographic embolization in haemodynamically unstable patients report success rates of up to 95%.8, 9 In cases where the bleeding cannot initially be controlled by selective angiographic embolization, then the use of temporary angiographic embolization of the internal iliac arteries bilaterally can be an option. Velhamos et al10 reported a 97% success rate using this technique in patients who had severe haemorrhage and did not respond to sub-selective embolization. It must be recognized than embolization of the internal arteries carries significant risks, such as infarction of the gluteal muscles with subsequent buttock necrosis.

The alternative management strategy for uncontrolled haemorrhage from a severe pelvic fracture is pelvic packing. This is executed through the lower end of a mid-line laparotomy incision but it is essential that the packs are placed retroperitoneally, either side of the bladder neck, towards the sacrum and sacroiliac joints. In this situation, pelvic external fixation to give posterior mechanical stability is usually necessary and the pelvic C-clamp is probably the most effective device.

Damage control resuscitation 

Damage control resuscitation is a concept that has been developed during times of war in order to address the challenges of military trauma. The main thrust of damage control resuscitation involves two strategies; permissive hypotension and haemostatic resuscitation, and is subsequently followed by damage control surgery. The aim of damage control resuscitation is to correct the three components of the “lethal triad” that occur in trauma victims.11 The concept of damage control resuscitation is not just limited to management of the trauma victims in the emergency department. Depending on the state of the trauma victim, it is often continued into the operating room or into the intensive care unit.

Lethal triad: the lethal triad is a term used to describe the combination of hypothermia, acute coagulopathy and acidosis that is found in the haemorrhaging trauma patient. The three aspects of the lethal triad are interlinked and the coagulopathy of trauma can be exacerbated by both acidosis and hypothermia.

Acute coagulopathy: coagulopathy has been found to be associated with higher rates of mortality when present on admission to a trauma centre. Brohi et al12 demonstrated that an acute coagulopathy was present in 25% of trauma patients and that this was associated with an increase in mortality (45% versus 10% in patients without coagulopathy). Further research looking at individual markers of coagulopathy associated with increased rates of mortality has found that patients admitted with a raised prothrombin time have increased adjusted odds of death by 35% and patients with a raised partial thromboplastin time have an increased adjusted odds of death by 326%.13

The exact mechanisms by which coagulopathy develops in the trauma patient are still not fully understood, but have been shown to be multifactorial in nature. Previously, the acute coagulopathy was thought to be related to a combination of haemodilution, the by product of resuscitation, and hypothermia. A review of the mechanisms of the coagulopathy of trauma by Hess et al14 expanded on original ideas and isolated six key initiators of coagulopathy in trauma: tissue trauma, shock, haemodilution, hypothermia, acidaemia and inflammation. Between these six main initiators there is a large degree of interaction and cross-over.

Permissive hypotension: when managing trauma victims in haemorrhagic shock, the previous teaching was to aggressively resuscitate the patient with fluids in order to restore normal intravascular volumes and end-organ perfusion in an attempt to prevent cellular ischaemia and organ damage.

The concept of permissive hypotension (also known as hypotensive resuscitation) is a different technique of resuscitation that is based on resuscitating the patient with fluids boluses, titrating the boluses to a lower than normal blood pressure (or radial pulse in pre-hospital care) in an attempt to preserve any clots that have formed and prevent further blood loss. This is continued until haemorrhage has been controlled, a period of decreased end-organ perfusion being accepted as a potential consequence.11 Once haemorrhage has been controlled, then a return to normal vital parameters and organ perfusion is required. The National Institute for Health and Clinical Excellence has issued guidance on permissive hypotensive resuscitation for the pre-hospital care of trauma victims, recommending that intravenous fluids should not be given if a radial pulse is palpable. If the radial pulse is not palpable, then fluid boluses up to 250 ml should be given and the pulse re-assessed.15

The use of hypotensive resuscitation is limited to trauma victims without associated head injuries. In patients with associated head injuries, the importance of maintaining cerebral perfusion is well documented and permissive hypotension is contraindicated in this group of patients.11

Haemostatic resuscitation: the concept of haemostatic resuscitation has been developed in an attempt to treat the acute coagulopathy of trauma victims and also to reduce the dilutional coagulopathy that can develop with conventional resuscitation. It involves the early use of red blood cells, plasma and platelets in a 1:1:1 ratio as the primary resuscitation fluids.11 The main features of this are outlined later in the section on massive transfusion protocols.

Prevention of hypothermia: hypothermia results from a combination of increased exposure, the administration of cold fluids and decreased endogenous heat production due to anaerobic metabolism. Whilst managing the trauma victim, prevention of hypothermia is much easier than reversal of hypothermia. Guidelines for management of peri-operative hypothermia have been set out by the National Institute for Health and Clinical Excellence, which recommend reduced exposure of the patient, use of forced air warming devices and warming of all blood products and intravenous fluids to 37 °C.16 Other intra-operative methods of reducing hypothermia include use of carbon polymer heating mattresses.11

Adequacy of resuscitation: monitoring the effectiveness of resuscitation of the trauma patient is of paramount importance in the early stages of patient care. Whilst vital parameters such as blood pressure, heart rate and urine output are very useful for monitoring the response to fluid resuscitation, they do not always reflect tissue perfusion. If cells are not receiving enough oxygen, there will be increased levels of anaerobic respiration leading to increased levels of lactic acid. This has led to the concept of occult hypoperfusion (OH). OH is usually monitored by the level of lactate in the blood, with a lactate >2.5 mmol/l despite normal vital parameters (heart rate <120 bpm, systolic BP >100 mmHg, urine output >1 ml/kg/h) constituting occult hypoperfusion.17 In patients where the blood pressure, heart rate or urine output are outside of the range outlined above, then the hypoperfusion is not considered to be “occult”.

A study by Blow et al17 looked at measurement of lactic acid in trauma victims with an injury severity score (ISS) ≥20 who were haemodynamically stable. The authors found patients who had occult hypoperfusion on admission that was corrected by 24 h had a 100% survival. If the occult hypoperfusion continued beyond 24 h, the mortality rate was 43%. In this group there was also a significantly higher rate of multi-system organ failure and respiratory complications in comparison to groups where the occult hypoperfusion was corrected within 24 h. It has also been demonstrated that patients who undergo fixation of femoral fractures within 24 h and before correction of occult hypoperfusion have a two-fold increase in post-operative complications (acute respiratory distress syndrome, multi-system organ failure, respiratory complications, infections, deep vein thrombosis).18

Young versus old red blood cells 

The age and length of storage of red blood cells have been shown to affect the outcome of trauma patients. A review by Vandromme et al22 discusses the mechanisms by which red blood cells are altered by storage. After storage of whole blood for 14 days, there is an accumulation of glycolytic metabolism byproducts, which results in functional and structural changes to red blood cells such that they are less pliable and therefore less able to reach end-organ capillary beds, leading to decreased oxygen delivery. After two weeks of storage, levels of 2,3-diphosphoglycerate (2,3-DPG) decrease in stored red blood cells, leading to reduced affinity of haemoglobin for oxygen and hence less oxygen delivery to the end organs per unit of haemoglobin. These levels of 2,3-DPG can take up to 72 h to recover after transfusion, which results in a delay in the overall effectiveness of the red blood cells in the initial phases.

Various studies have been performed looking at the effects of young versus old red blood cell transfusions in trauma patients. These studies are limited by the fact that they are reporting the effects after evaluating patients who have received a mixture of young (<14 days) and old (>14 days) transfusions, and also the effect of the volume of red blood cells transfused is not insignificant. Weinberg et al23 investigated the effect of young versus old blood transfusions on trauma victims (mean ISS 26) and found that in patients who received three or more units of old red blood cells, there was a greater than two-fold increase in the odds of death. A further study by Weinberg et al24 found that in patients with less severe blunt trauma (ISS <25) there was an independent association with risk of death, acute renal failure and pneumonia in patients receiving old red blood cells.

Calcium 

Calcium is one of the co-factors that plays a role in the coagulation cascade. A study by Cherry et al25 found that trauma patients with an ionized calcium <1.0 mmol/l on admission had a significantly higher mortality compared to patients with an ionized calcium >1.0 mmol/l (26.4% versus 16.7% respectively). Patients who undergo transfusion are also at risk of exacerbation of hypocalcaemia. Citrate is used as one of the anticoagulants in some blood components, and it chelates calcium which can lower serum ionized calcium. A review by Lier et al26 recommends maintaining an ionized calcium concentration ≥0.9 mmol/l in an attempt to reduce the risk of exacerbation of coagulopathy.

Recombinant factor VIIa (rfVIIa) 

Factor VIIa plays an important role in the coagulation cascade and the theoretical ability of rfVIIa to reduce bleeding has led to many studies of its use. RfVIIa is currently only licensed for use in haemophilia patients with inhibitory allo-antibodies. A study by Boffard et al27 found a significant reduction in red cell unit requirements over a 48 h period after administration of rfVIIa in patients who had sustained blunt trauma.

A Cochrane review28 of 13 randomized controlled trials of rfVIIa use in both prophylactic and therapeutic settings to reduce bleeding found no reliable evidence of an advantage of rfVIIa over placebo, though there was a trend to a decrease in mortality with rfVIIa use. It also found a trend towards an increased incidence of thromboembolic disease after the use of rfVIIa although again this was non-significant. Concerns regarding these complications have lead to a recent restriction in using rfVIIa by the military.