Trauma

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CHAPTER 12 TRAUMA

INTRODUCTION

The successful management of major trauma requires early identification and treatment of life-threatening injuries followed by systematic evaluation and treatment of all other injuries. Best outcomes are achieved by a coordinated team approach and protocol-based management.

Depending upon local policy, you may be called to assist in the initial resuscitation of major trauma victims. Although an A&E doctor or trauma surgeon will generally lead trauma resuscitation, you should be familiar with advanced trauma life support protocols.

PRIMARY SURVEY

The purpose of the primary survey is to identify and begin the treatment of any immediately life-threatening injuries. These include:

The principal elements of the primary survey are A, B, C and D, as follows.

EXPOSURE AND SECONDARY SURVEY

Once the initial survey is complete and the patient is stabilized, ensure that appropriate monitoring is established and that necessary investigations have been organized (Box 12.1).

Box 12.1 Investigations and monitoring

Routine investigations	Monitoring
FBC	ECG
U&Es, glucose	Blood pressure (non-invasive or invasive)
Arterial blood gases	Pulse oximeter
(Pregnancy test)	CVP
ECG	Urine output
Lateral cervical spine X-ray
Chest X-ray
Pelvic X-ray
Urine (stick test)

Ensure that an adequate medical history has been obtained. At a minimum, this should include the patient’s past medical history, medications, allergies, time of last meal and the mechanism of injury. The mechanism of injury is particularly important in providing important clues as to the likely injuries that may have been sustained.

Completely expose the patient, while at the same time taking steps to avoid hypothermia.

Systematically examine the patient from head to toe, looking for other injuries.

Log roll the patient to examine the back and spine, and perform rectal and vaginal examinations.

A urinary catheter and nasogastric tube may be inserted if there are no contraindications.

Following resuscitation, stabilization and re-evaluation of the patient, further management can be planned. This may include immediate surgery for life-threatening injuries, or further investigations such as ultrasound or CT scan.

Ultrasound is increasingly used to identify free fluid (blood) in the peritoneal, pleural and pericardial spaces. In this context, its value is in identifying a problem (e.g. peritoneal fluid) rather than the definitive diagnosis (e.g. ruptured spleen). There is much current interest in the use of ‘focused’ ultrasound examinations in trauma, which are easily learned and reliably performed by non-specialist medical staff (e.g. the ‘FAST’ scan) (Trauma Ultrasonography. The FAST and Beyond. http://www.trauma.org/archive/radiology/FASTintro.html).

Many larger centres also now routinely perform CT scanning of chest, abdomen, head and spine in all patients with a significant history of major trauma. With modern fast scan times such approaches are increasingly seen to optimize care in these vulnerable patients; occult injuries are often found.

Blunt versus penetrating trauma

Blunt and penetrating trauma produce different patterns of injury. Blunt trauma is associated with significant soft-tissue injury and haemorrhage into tissues and body cavities. In penetrating trauma, tissue injury may be quite localized and haemorrhage may be tamponaded by clot or the presence of a foreign object. There is ongoing debate about resuscitation strategies in the two groups.

Aggressive intravenous fluid resuscitation with blood, colloid or crystalloid may raise blood pressure, disturb blood clots and restart bleeding. There is some evidence, particularly in penetrating trauma, that restrictive fluid strategies, which limit the volume of resuscitation fluid given until surgical control of bleeding can be achieved, are associated with better outcomes. Similar considerations may apply in other surgical situations, such as leaking aortic aneurysm.

INTENSIVE CARE MANAGEMENT

Patients with multiple injuries frequently require transfer to an ICU after initial resuscitation, stabilization and surgery. Care of the multiply injured patient is essentially no different to care of any other ICU patient. Multiple trauma is by its nature a multisystem disorder, rather than a collection of isolated injuries. Treatment is generally supportive, with appropriate intervention for problems as they are identified.

Multiple organ failure

Multiple organ failure is common after massive trauma. Typically patients develop a systemic inflammatory response syndrome (SIRS), 24–48 h after apparently adequate resuscitation, which then progresses to multiple organ failure. Tissue damage, activation of the immune system and massive blood transfusion are all implicated but exact mechanisms are still not fully understood. Treatment is largely supportive. Possible sources of any ongoing inflammatory response, including necrotic tissue and foci of infection, must be excluded. (See Multiple organ failure, p. 329, and SIRS, p. 326.)

The management of specific groups of injuries is discussed below.

HEAD, FACE AND NECK INJURIES

Head injury

(See Traumatic brain injury, p. 274.)

Facial injury

In the unconscious or obtunded patient the airway should be secured early by intubation. With time, swelling may make subsequent reintubation or airway manipulation impossible. In severe injuries consideration should be given to early tracheostomy. In the presence of facial or base-of-skull fractures, avoid nasal intubation or nasogastric tubes as these may pass into the cranium. Use the oral route.

Heavy bleeding from facial injuries should not be underestimated. Bleeding from the nose may require nasal packing to tamponade bleeding. Seek ENT / maxillofacial surgical advice. Injuries to the jaw often require internal fixation and jaw wiring. Do not be afraid to cut the wires in the event of airway problems. When extubating these patients, ensure they are awake and have full return of protective reflexes before removing the endotracheal tube.

Broken or dislodged teeth may be aspirated. These are usually visible on X-ray, but are not usually densely radio-opaque unless there are amalgam filling present. Careful scrutiny of films is required and a lateral film may help to confirm position (note position of NG tube to delineate the oesophagus). Rigid bronchoscopy may be required for the location and removal of radiolucent teeth / fragments. (See Airway obstruction, pp. 138, 309.)

Cervical spine injury

(See Spinal cord injury, below.)

Cervical soft-tissue injury

Direct injury to soft tissues of the neck can result in airway compromise, due either to haematoma / tissue swelling causing compression of the airway or to direct injury to the larynx or trachea. Secure the airway by early intubation and seek expert surgical help. Vascular injuries in the neck may compromise the cerebral circulation. Dissection of the carotid arteries by blunt injury from seatbelts or other trauma is rare but easily missed. Bleeding may track down into the chest, resulting in haemothorax or haemomediastinum and rarely cardiac tamponade. Carotid dissection can be identified using ultrasonography, CT scan or angiography.

SPINAL CORD INJURIES

Spinal cord injury may occur as a result of trauma, vertebral collapse, infection, tumours, infarcts and other pathologies. The classic features of complete spinal cord injury are total loss of motor and sensory function below the level of the injury. (In the acute setting, the apparent level of the injury may be higher than actual due to inflammation and oedema around the site of injury.) A number of patterns of incomplete injuries are also recognized (Table 12.1).

TABLE 12.1 Patterns of spinal cord injury

Complete cord injury	Total paralysis and loss of sensation below level of injury
Cord hemisection, Brown–Séquard syndrome	Ipsilateral paralysis and contralateral loss of sensation below level of lesion
Central cord syndrome	Greater motor loss in upper limbs than lower. Variable sensory loss below level of lesion
Anterior cord syndrome	Paralysis, loss of pain / temperature sensation below level of lesion Proprioception and vibration preserved

In all cases of significant trauma, assume that the spine (cervic, thoracic or lumbar) is injured until proven otherwise and immobilize it as part of initial resuscitation. Signs suggestive of spinal cord injury in an unconscious patient are given in Box 12.2.

Box 12.2 Signs suggestive of spinal cord injury in an unconscious patient

Diaphragmatic pattern of breathing

Unexplained hypotension / bradycardia

Absence of response to pain (below level of lesion)

Flaccid paralysis / areflexia

Reduced anal tone

Urinary retention

Priapism

Management

X-rays of the spine do not exclude instability resulting from ligament injury. Spinal cord damage can only befully excluded by clinical examination in an awake, co-operative patient. Therefore, even if X-rays are normal, you should maintain immobilization until the spine can be assessed clinically. CT or MRI can give further information.

Follow advanced trauma life support protocols (see p. 306).

Immobilize the spine to prevent secondary damage. Use a cervical collar, sandbags and tape for cervical spine, plus spinal board. (Log roll with inline stabilization to control head and neck movement.)

Establish i.v. access. Give volume load to support the blood pressure.

Sympathetic interruption from cord injury will produce hypotension and bradycardia, depending upon the level of cord injury. Vasopressors / inotropes may be required to maintain the circulation. Exclude haemorrhage from other injuries (e.g. in the ‘silent’ denervated abdomen).

Tracheal intubation and assisted ventilation may be required for respiratory insufficiency or to facilitate surgery. Consider awake fibreoptic intubation using local anaesthesia. Alternatively, intubate the anaesthetized patient with inline immobilization of the neck. The use of a bougie and McCoy laryngoscope or video laryngoscopes limit the need to extend the neck.

Gastric stasis is common: pass a nasogastric / orogastric tube.

Urinary retention is common (and is an important cause of spinal hyperreflexia). Pass a urinary catheter.

High-dose steroids (methylprednisolone), if given early, may have beneficial effects in spinal injury.

Discuss the management with the local spinal injuries unit or spinal surgeon. The indications for early spinal decompression and surgical stabilization are controversial. Transfer to a spinal injury unit only after exclusion and stabilization of other injuries in a general / neurosurgical unit.

Suxamethonium can be used in the first few hours after injury. Avoid after 24 h because of the potential for massive K⁺ release. (See Suxamethonium, p. 43.)

Respiratory complications are the leading cause of death following cervical cord injury. Marked changes in respiratory physiology / mechanics occur and recovery can be prolonged as a result of impaired ventilation and cough reflexes. This leads to predictable difficulties weaning from artificial ventilation. Early tracheostomy may be of benefit. Those with injuries at a level to effect the phrenic nerve (C3, 4, 5) may remain ventilator-dependent in the long term.

THORACIC INJURIES

Pneumothorax

All traumatic pneumothoraces should be drained. (See Practical procedures, p. 416.)

Massive air leaks may require bronchoscopy to exclude bronchial rupture. Bronchial rupture should be suspected in the presence of deceleration injury, mediastinal widening, haemoptysis, first rib or clavicular fractures. An urgent thoracic surgical opinion should be sought, as surgical repair is usually required.

Haemothorax

This requires early drainage. Once clot becomes well established it becomes difficult to drain and thoracotomy may be required later. Initial drainage > 600 mL or continuing drainage > 150 mL / h needs urgent surgical referral. Before attempting drainage of massive haemothorax, ensure good venous access, as decompression of a vascular tear can sometimes occur, resulting in massive haemorrhage. A large drain (28–32 Fr) will generally be required to drain blood effectively.

Rib fractures

These are significant because of the potential for injury to the underlying viscera. Elderly patients with brittle ribs may have impressive rib fractures with little underlying injury. Conversely, younger patients with more flexible ribs may have severe visceral injury without obvious fractures.

Apical rib fractures are associated with injury to great vessels.

Mid-zone rib fractures are associated with pulmonary contusions.

Basal rib fractures are associated with abdominal visceral injury (liver, spleen, kidneys).

Simple rib fractures without major visceral injury can often be managed conservatively. Adequate analgesia is essential, consider patient-controlled analgesia ± NSAIDs, continuous thoracic epidural, or paravertebral block. Supplemental oxygen, CPAP and physiotherapy are useful.

In the presence of a significant flail segment and underlying pulmonary contusions, IPPV is generally required and should be instituted early before exhaustion and significant hypoxia develop. Typically assisted ventilation will be required for 7–10 days in such cases. Severe life-threatening ARDS may develop.

There is little place for surgical fixation of the rib cage. Assisted ventilation (IPPV and PEEP) will usually restore reasonable alignment of a distorted rib cage over a few days. Occasional patients require thoracic or plastic surgical intervention for debridement of contaminated wounds, reconstruction of missing part of chest wall or protruding rib(s).

Mediastinal injury

Rapid deceleration injuries can result in injury to the mediastinal contents; in particular, traumatic transection of the aorta or other great vessels. Many patients with such injuries will die before reaching hospital, but some develop a contained rupture that is at risk of massive rebleeding at any time, hours or even days ahead. The typical finding is that of a widened mediastinum on CXR. Typical features are shown in Fig. 12.1.

Fig. 12.1 Chest X-ray appearances of possible mediastinal haematoma (widened mediastinum).

Investigations include aortic angiography and spiral CT scan. Transoesophageal echocardiography may have a role but does not provide all the information required for surgery. Not all cases of bleeding into the mediastinum will require surgery. Smaller venous bleeds may be managed conservatively. Always seek advice.

The management of great vessel injury is increasingly by radiological stenting rather than open surgery, where such facilities exist. Refer the patient to cardiothoracic surgeons, vascular surgeons, or vascular interventional radiologists. Immediate management includes controlled hypotension (e.g. GTN or esmolol infusion).

Cardiac contusions

Blunt trauma to the anterior chest wall can result in injuries to the myocardium, coronary arteries, valves and other related structures. The presence of a fractured sternum should raise suspicion. Typically myocardial contusions may result in dysrhythmias and ischaemic injury patterns on ECG. These are often transient and not significant but dysrhythmias may require appropriate intervention. Rarely, injury to the anterior descending coronary artery may lead to myocardial infarction. Perform serial 12-lead ECGs and send blood for troponin. Echocardiography can indicate dyskinesia suggestive of myocardial contusion, valvular damage, and pericardial effusions. Transthoracic views may be sufficient, but have poor sensitivity for detecting aortic dissection or root injury. A transoesophageal echo or CT angiogram (where available) are valuable for excluding these diagnoses. Seek specialist advice.

Ruptured diaphragm

Blunt trauma to the abdomen may cause the diaphragm to rupture. This usually occurs on the left, due to the protection afforded by the liver on the right. The diagnosis is suggested by abdominal visceral gas shadows in the chest. Check the position of the NG tube as a marker of stomach position. Surgical repair is indicated via the chest or abdomen. Occasional patients have a missed ruptured diaphragm and present later with strangulation of hernia contents. Rupture of the diaphragm may also occasionally be a long-standing, incidental finding. In these situations do not confuse X-ray appearances of viscera in the chest with pleural fluid / gas collections needing a chest drain!

ABDOMINAL INJURIES

Any intra-abdominal structure can be damaged. Major visceral injury may be obvious, but more minor injuries such as mesenteric tears are easily missed. Pain, guarding, distension, and presence or absence of bowel sounds cannot be reliably elicited in the unconscious, sedated and ventilated patient. If previously unrecognized injury or continued intra-abdominal bleeding is suspected, seek immediate surgical opinion. Investigations including ultrasound and CT scan may be helpful, but all can potentially miss significant injuries. If doubt remains, laparotomy should be considered.

Ruptured spleen

Surgeons increasingly try to preserve the spleen following injury and there is a place for conservative management of more minor injuries to the spleen. Patients following splenectomy tend to show initial raised white count in the postoperative period. Following splenectomy there is greatly increased risk of life-threatening infection (particularly pneumococcal). Patients require long-term prophylaxis with penicillin (2 years minimum) and immunization against Pneumococcus, Meningococcus, and Haemophilus influenzae in the convalescent phase. (See BNF and local guidelines.)

Ruptured liver

Where possible, liver trauma is managed conservatively. Post-traumatic liver haemorrhage is often amenable to radiological intervention (embolization). Where laparotomy is unavoidable, surgeons may pack the liver bed and close the abdomen, with the aim of returning to theatre after 48 h. If haemodynamically stable, patients with liver rupture should be transferred to a specialist unit.

Abdominal compartment syndrome

If intra-abdominal pressure rises above venous pressure (e.g. as a result of intra-abdominal haemorrhage) then perfusion to the abdominal organs is impaired. The first indication may be a falling urine output in the presence of an increasingly tense and quiet abdomen. Intra-abdominal pressure can be measured by connecting the urinary catheter to a pressure transducer. Intra-abdominal pressures above 20 mmHg, together with evidence of end organ dysfunction, are suggestive of abdominal compartment syndrome. The management is surgical exploration (see p. 174).

Patients may bleed torrentially when the abdomen is opened and become haemodynamically unstable following visceral reperfusion. In some cases, it may be necessary to leave the abdomen ‘open’ after decompression. Closure may be achieved either after a few days, when the cause of the abdominal distension has subsided, or much later after the primary defect has closed by granulation. Abdominal distension can impede diaphragmatic function and make weaning from ventilation difficult (see Weaning, p. 135).

SKELETAL INJURIES

Pelvic injuries

Pelvic injuries can result in major blood loss. Unstable pelvic injuries are managed by early external fixation, which is typically performed in A&E. This helps to reduce bleeding and ultimately allows for earlier mobilization.

Urethral injury should be considered in all cases of pelvic injury. Suspect if there is bleeding from the urethral meatus or an abnormal rectal examination. Do not attempt urethral catheterization. Seek help from urologists. Diagnosis is by urethrogram, which can be performed in A&E. Contrast is injected via the urethra, looking for extravasation on X-ray. Management is by suprapubic catheter, with definitive repair at a later date.

Long bone injuries

Look for obvious limb deformity and check for neurovascular integrity. Early reduction of deformity and splinting reduces bleeding and pain. (See also Fat embolism, Compartment syndrome and Rhabdomyolysis below.)

The timing of internal fixation of significant long bone fractures in the face of other multiple injuries is controversial. In principle, early fixation is ideal. There is some evidence, however, that fixation may have adverse effects on ICP and may also worsen acute lung injury / ARDS. Furthermore, it is pointless spending 8–12 h in theatre undertaking extensive orthopaedic instrumentation when the patient stands little chance of survival. In unstable patients and those with significant head injury, fixation may therefore be better delayed. As a result, there has been much study in recent years of the best timing for definitive orthopaedic surgery. The evidence seems to favour either immediate or delayed as ‘safe’, with intermediate time points carrying a higher risk of the ‘second hit’ phenomenon.

FAT EMBOLISM

Fat embolism classically presents with dyspnoea, hypoxaemia, petechial rash and acute confusional state following long bone fracture or orthopaedic instrumentation. The signs are non-specific and can be caused by pneumonia, sepsis and other complications of trauma and surgery. The mechanisms by which fat embolism occurs are not clear. The simplest explanation is embolization of fat from long bone marrow into the circulation, and then to the lungs and other organs. This does not explain how fat droplets cross the lungs into the systemic circulation to produce CNS effects, nor why most patients do not develop the condition despite the common presence of fat droplets in the circulation after long bone injury. Although operative intervention may precipitate fat embolism, trauma studies suggest that early orthopaedic fixation of fractures reduces the overall incidence of clinically significant fat embolism.

Investigations

The diagnosis is often one of exclusion. Fat droplets may be seen in retinal vessels, sputum or urine: none of these findings is specific for the condition. CT scan of the brain is usually normal or shows mild diffuse cerebral oedema; MRI scans show areas of microinfarction in severe cases.

Treatment

Management is essentially supportive. Respiratory insufficiency may progress to severe ARDS. The CNS signs usually settle over time but occasional patients develop severe brain injury, with long-term damage or even death.

PERIPHERAL COMPARTMENT SYNDROMES

After initial resuscitation, injured areas often become swollen. Swelling of soft tissues where muscle groups are restricted by fascial layers may result in increased pressure inside the compartments. This restricts blood flow to and from the muscles, which become ischaemic. If left untreated, necrosis, rhabdomyolysis and late ischaemic contractures may develop. This is well recognized in the calf or forearm, but can also occur in the upper arm, thigh, buttocks and in other areas.

Compartment syndrome may be caused by any process that leads to soft-tissue swelling, including infection, haemorrhage or ischaemia. Typical causes are shown in Box 12.3.

Box 12.3 Typical causes of peripheral compartment syndrome

Forearm fracture

Lower limb fracture

Vascular injury (including surgery)

Reperfusion injury

Pressure from any cause (including crush injury / coma)

Local infection

Local haemorrhage

Diagnosis relies upon clinical suspicion. Look for swollen, tense and painful muscles (particularly on extension) in the calf and forearm. Remember pain may be masked by epidural / regional anaesthetic blocks. Pulses may be absent but are not invariably so. Diagnosis is confirmed by measurement of compartmental pressure, obtained by insertion of a 21-gauge (green) needle connected to a flush device and pressure transducer (as for any intravascular monitoring). It should be appreciated that there are multiple compartments in each limb so measurement requires knowledge of the appropriate anatomy (seek advice). Pressures greater than 30 mmHg are an indication for fasciotomy and debridement of dead muscle. This can be performed in the ICU. Wounds are left open, and closed subsequently when swelling subsides. Seek surgical advice.

RHABDOMYOLYSIS

This classically occurs after lower limb crush injury, but can occur following injuries to any muscle group or even from necrotic muscle in surgical wounds. It may follow a missed compartment syndrome. It also occurs with prolonged immobility, e.g. following drug overdosage, epilepsy or head injury. Muscle breakdown (rhabdomyolysis) releases toxic products into the circulation. These produce a systemic inflammatory response syndrome, which may progress to multiple organ failure. In addition, myoglobin specifically precipitates in renal tubules and causes ARF.

Management

The management involves prevention, recognition of the problem and supportive care. Measure creatinine kinase (CK), which is usually greater than 5000 units, and urinary myoglobin (rapidly disappears after a few hours). Exclude and treat compartment syndromes and excise dead muscle (amputation may be required).

Myoglobinuria

Fluid loading and diuretics help maintain urine output. An alkaline diuresis may prevent myoglobin precipitation in the renal tubules. Replace the hourly urine output + 50 mL with alternating hours of 1.4% bicarbonate solution and 5% dextrose. In addition give 0.5 g / kg mannitol. Measure serial urine pH, and aim to keep in alkaline range. Continue this regimen until resolution of myoglobinuria. (See Forced alkaline diuresis, p. 232.)

Should renal failure occur, supportive treatment is required. Once renal failure is established, the course typically follows that of ATN, with gradual complete recovery of renal function. (See Indications for renal replacement therapy, p. 140.)

BURNS

Patients with extensive burn injuries (>20% body surface area) are usually managed in regional burns centres. You may, however, be called to help in the initial resuscitation of a burns victim or may be required to manage the patient in the general ICU because of other coexisting problems. A typical chart for the assessment of burn area is shown in Fig. 12.2.

Fig. 12.2 Assessment of burns – Lund and Browder charts.

Resuscitation

The basic principles of resuscitation of the burn victim are the same as for any other patient. The main problems relate to the potential for thermal injuries to the airway, large fluid losses and potential for infection.

Give humidified oxygen by face mask. If there are extensive facial burns, or any evidence of thermal injury to the airway, the airway should be secured by endotracheal intubation. This should be performed electively before oedema and swelling make intubation impossible.

Establish i.v. access. Where possible, avoid siting cannulae through burned skin, to reduce the risk of infection. (Ultrasound is helpful to guide central venous cannulation if burns are extensive.)

Give i.v. analgesia and commence fluid resuscitation.

The fluid requirements depend on the size of the burn. This is estimated from the rule of nines or from burns charts. A number of regimens are described for fluid replacement based on either crystalloid or colloid infusion. Examples are shown in Box 12.4.

Box 12.4 Examples of fluid regimens for the resuscitation of burns victims

Mount Vernon formula	Parkland formula
4.5% albumin	Ringer lactate
Volume (mL) = 0.5 × weight (kg) × % burn	Volume (mL) = 4 × weight (kg) × % burns
Over six consecutive periods of 4, 4, 4, 6, 6 and 12 h each	Given over 24 h