Primary survey

Table 4.1 outlines the priorities for the first few minutes of treating an injured patient. Each of the ‘ABCDE’ priorities is paired with an equally important task. The usual sequence of history, examination, investigation and treatment seen in non-emergency situations is abandoned. Treatment of immediately life-threatening conditions is instigated simultaneously with ongoing assessment.

Table 4.1 Sequence and priorities for primary survey

Adjuncts to primary survey

Secondary survey

The secondary survey comprises a complete history and examination and does not take place until the primary survey is complete.

Haemorrhagic shock

Severe haemorrhagic shock, characterised by tachycardia, hypotension, cold peripheries and oliguria, is straightforward to recognise, but the early stages may be less obvious, especially in a young and fit patient who can maintain a normal systolic pressure surprisingly well until further bleeding precipitates sudden collapse. Any trauma patient who is tachycardic and has cool peripheries must be assumed to be shocked until proven otherwise.

Haemorrhage is classified into four levels (Table 4.2), which are useful when estimating likely blood loss but are rarely clearly defined in practice. In true emergency situations patients are considered as responders, transient responders and non-responders, depending on the change in circulatory status following infusion of the initial bolus of 2000 mL warm crystalloid solution. Rapid responders who remain stable after the initial bolus do not need transfusion. Transient and non-responders need urgent blood transfusion and surgical intervention to identify and stem ongoing bleeding. When tracking down major haemorrhage in a hurry it is helpful to remember blood loss can only be in four places (and how to identify each in parentheses):

Blood in the chest, long bone fractures and major external haemorrhage are fairly easy to detect; most major occult blood loss is into the abdomen (see ‘Abdominal trauma’, p. 65).

It is important to realise that the early stages of haemorrhagic shock may not be obvious, and if unrecognised may suddenly progress to collapse which may be too late to reverse. This is especially true in the elderly and athletes, and in hypothermia and pregnancy. Beware beta-blockers and pacemakers, which may prevent the patient mounting a tachycardia.

Arterial blood gas estimation is very useful in assessing whether a patient is adequately resuscitated, since shock causes inadequate perfusion and the tissues become hypoxic, shifting to anaerobic respiration leading to acidosis. Urine output is also a useful guide.

Fluid resuscitation

When using crystalloid fluid for resuscitation, each unit volume of lost blood must be replaced by three times the volume of the crystalloid solution. Fully cross-matched blood is best for transfusion but takes time to prepare. Type-specific (ABO) blood is available much more quickly. Group O rhesus-negative blood is reserved for catastrophic exsanguinating haemorrhage (but see Box 4.2).

Tension pneumothorax: needle thoracocentesis

A tension pneumothorax occurs when the pleura is breached, allowing air to escape into the pleural cavity. Trapped air accumulates in the pleural cavity under increasing pressure, squashing the remainder of the chest contents. This causes hypoxia, agitation (‘I can’t breathe’), tachycardia, tachypnoea, cyanosis, distended neck veins, tracheal deviation away from the affected side, hyper-resonant percussion note and absent breath sounds. It is a clinical diagnosis and requires immediate treatment: the patient will die if you wait for a chest X-ray.

Decompress the tension immediately passing a large-bore IV cannula into the pleural cavity through the midclavicular line in the second intercostal space. An immediate ‘hiss’ will be heard as the high pressure air escapes. This converts a tension pneumothorax into an open pneumothorax and buys enough time to insert a formal chest drain.

Open pneumothorax

An open chest wound allows air to be sucked into the pleural cavity on inspiration and forced out on expiration (hence the term ‘sucking chest wound’). If the hole in the chest is wider than the diameter of the trachea, air is sucked in and out of this opening in preference to moving air in and out of the lungs via the airway. The patient rapidly becomes exhausted and hypoxic trying to breathe with the futile effort of forcing air in and out of the open wound.

Immediate management is to close the defect with an occlusive dressing taped down on three sides. This allows air out of the pleural cavity on expiration but on inspiration the dressing is sucked against the chest wall preventing re-entry of air. This improves the situation long enough for a formal chest drain to be inserted at a site away from the wound.

Massive haemothorax

The accumulation of over 1500 mL of blood in the chest causes hypoxia by restricting lung expansion and shock due to class III/IV (i.e. major) blood loss. The chest is dull to percussion over the haemothorax and breath sounds are absent.

Management requires immediate fluid resuscitation and simultaneous decompression of the pleural cavity with a chest drain.

If available, auto-transfusion equipment allows large volumes of blood collected via the chest tube to be transfused immediately.

A patient who drains more than 1500 mL blood on initial insertion of the chest drain, or who continues to drain more than 200 mL per hour for 2–4 hours, is likely to need a thoracotomy. These volumes are guidelines; the indication for surgery depends more on the patient’s general state, and the diagnostic and surgical facilities available.

Flail chest

A flail chest (or flail segment) occurs when one or more ribs are fractured in more than one place. This results in a segment of the rib cage losing bony continuity with the rest of the chest wall. Flail segments usually result from severe blunt trauma and the underlying lung is often severely contused, exacerbating the respiratory difficulty. The work of breathing is inefficient (as the flail segment is sucked in as the chest is expanded, and vice versa – this is known as ‘paradoxical respiration’) and painful.

Crepitus of fractured ribs may be palpable but the presence and extent of a flail chest is best shown by a chest X-ray. The patient may cope for some hours but most patients with flail segment injuries develop respiratory failure (evidenced by deteriorating oxygen saturations and arterial blood gases) and the majority will require a period of assisted ventilation while the underlying lung recovers. In less severe cases, an intercostal nerve block may ease the pain of breathing sufficiently to avoid artificial ventilation.

Cardiac tamponade

Cardiac tamponade is a similar phenomenon to tension pneumothorax in that blood collects in the pericardial cavity following cardiac injury and has nowhere to escape to. The blood accumulates and compresses the heart, preventing venous return and limiting cardiac output. The signs are tachycardia, with hypotension, distended neck veins and muffled heart sounds (Beck’s triad). Immediate pericardial aspiration is required.

Cardiac tamponade may be difficult to diagnose. Additional clues are increased pulsus paradoxus (decrease in systolic pressure on inspiration) and Kussmaul’s sign (increase in venous pressure on inspiration) but these signs are difficult to elicit with confidence in the emergency setting.

Pulseless electrical activity in the absence of hypovolaemia or pulmonary embolism is suggestive of cardiac tamponade. Echocardiography, if available, may confirm the diagnosis.

Other chest injuries

While the ‘ATOM-FC’ (Box 4.1) injuries must be detected early, there are other thoracic problems that may not be obvious initially but which can be lethal if missed.

The chest X-ray in trauma

A systematic approach helps to detect all the useful information that a CXR provides for injured patients (Table 4.3). Rib fractures and pneumothoraces are more easily spotted if the film is rotated 90°.

Table 4.3 Systematic approach to the chest X-ray in trauma

CT scanning and aortography may help confirm or exclude abnormalities suspected on the chest film.

Insertion of a chest drain

Chest drains are required for the relief of a large pneumothorax (after release of a tension pneumothorax), surgical emphysema, haemothorax and pleural effusion/empyema – see Chapter 24.

History

Any penetrating trauma to the trunk, or high impact injury (high speed car crash or fall from height) is likely to cause intra-abdominal damage.

Examination

The abdominal examination of the traumatised patient is surprisingly unhelpful, even in experienced hands. Coexisting pain in other parts of the body, alcohol, depressed level of consciousness, shivering and superficial trunk injuries all confound the assessment of the abdomen. Surprising amounts of blood may be lost into an apparently painless and soft abdomen. Equally, broken ribs and muscular bruising may cause extreme pain and guarding while palpating an otherwise unharmed torso. Thus even a careful inspection/palpation/percussion/auscultation examination may neither confirm nor exclude underlying injury.

The examination must include inspection of the back and perineum and a rectal examination, best done at the time of the log roll.

There are four things to check during the rectal examination:

Urethral trauma is suggested by blood at the meatus, perineal/scrotal bruising, a high riding prostate or a pelvic fracture.

Some signs are helpful pointers. The imprint of a steering wheel, seat belt or tyre mark on the trunk suggests serious damage. A fractured pelvis is often associated with abdominal (usually extraperitoneal venous) bleeding. A penetrating wound which when probed reveals bile or bowel content (use a culture swab; the gentle cotton tip is ideal) obviously needs laparotomy, but around a third of stab wounds do not penetrate the peritoneum, and not all those that do require surgery.

Investigation

Table 4.4 outlines the advantages and disadvantages of ultrasound, diagnostic peritoneal lavage (DPL) and CT scanning for abdominal trauma. For all but very unstable patients, CT scanning is by far the superior modality.

Table 4.4 Comparison of ultrasound, diagnostic peritoneal lavage and CT scanning for abdominal trauma

Blood tests

The blood tests performed when blood is taken during the primary survey must include a serum amylase (retroperitoneal trauma can be difficult to diagnose – the first indication may be a raised serum amylase).

Plain films

Broken ribs on the CXR or a fractured pelvis raise the likelihood of abdominal trauma.

CT scanning

Unless the patient is very unstable, CT scanning is the best way to diagnose (or exclude) intra-abdominal injury.

Diagnostic peritoneal lavage

Popular at one time, but now largely superseded by CT scanning.

Ultrasound

Quick and accurate in skilled hands but limited information about retroperitoneal structures and not sufficient to exclude splenic rupture.

Contrast studies

Intravenous urography and retrograde urethrography may help define urological trauma. Contrast studies are occasionally indicated for gastrointestinal trauma.

Laparoscopy

Popular in some trauma centres; laparoscopy is particularly accurate in confirming/excluding diaphragmatic trauma in upper abdominal/lower chest stabbings.

Laparotomy

Indications for laparotomy include:

Since a traumatised retroperitoneum is not easy to assess at laparotomy, patients who have clear clinical indications for exploratory laparotomy may still benefit from prior CT scanning if they are sufficiently stable.

Non-operative management

Accurate CT diagnosis of certain injuries, for example contained splenic haematoma or blunt renal trauma, may allow conservative treatment of conditions which would in the past have required surgery. Such patients need close monitoring (‘active re-observation’) and serial imaging with CT or ultrasound. See also Box 4.3.

Minor head injuries

This category includes patients who arrive at hospital having been knocked out, but who are essentially back to normal (i.e. no neurological signs) when examined. In general, those with only a short period of loss of consciousness, no amnesia, no skull fracture and who have reliable, sensible relatives may be discharged with instructions to return should problems develop (all A&E units have ‘head injury instructions’ for carers).

Those who were unconscious for longer periods, who have been drinking alcohol or have a skull fracture should be admitted for a minimum of 24 hours for neurological observation. Patients who have a clinical indication for admission (e.g. no carer at home) do not necessarily require skull X-rays; they simply require observation, with immediate CT scanning if they deteriorate (Fig. 4.1). CT has become the first-line investigation in head injury assessment.

Figure 4.1 NICE guidelines for investigating clinically important brain injury. Selection of a) adults and (b) children for CT

(from Head injury: Triage, assessment, investigation and early management of head injury in infants, children and adults. Clinical Guideline 56. NICE 2007, with permission)

Major head injuries

The Glasgow Coma Score (Table 4.5) is a reproducible way of quantifying depression of consciousness and should be assessed in all significant head injuries.

Table 4.5 The Glasgow Coma Score

Types of brain injury

Extradural haematoma (Fig. 4.2a)

The classic history is of a boxer knocked out in the ring who returns to normal (the lucid interval) then subsequently collapses unconscious. The extradural haematoma is usually the result of damage to the middle meningeal artery.

Figure 4.2 CT scans. (a) Left extradural haematoma obliterating the ventricle and shifting the midline to the right. (b) Left chronic subdural haematoma.

Treatment

Assume all head-injured patients have a cervical spine injury until proved otherwise. The priority is to prevent secondary brain injury by providing maximum perfusion and oxygen delivery to the brain while the type of injury is determined by CT scan. Intubation, ventilation with 100% oxygen and resuscitation of the shocked patient is paramount. Isolated head injuries never cause hypotension, therefore search for other causes of shock in hypotensive patients. For isolated head injuries, some neurosurgical units advise mannitol and hydrocortisone to reduce cerebral oedema. Intracranial haematomas need neurosurgical consultation with a view to evacuation. Intracranial pressure measurement may be helpful to monitor progress.

Prognosis

See Table 4.6. Hypotension is thought to have particular relevance: intracranial perfusion pressure = MAP−ICP.

Table 4.6 Outcome in head injury with coma on admission

Types of spinal injury

Spinal cord injury may occur without bony injury (SCIWORA; spinal cord injury without radiological abnormality), and vice versa, but they usually coexist.

Like the brain, injury may be primary due to damage on impact, or secondary resulting from hypoxia, hypoperfusion, haematoma or movement of an unstable spinal fracture. Cord function below the lesion is lost.

Damage below the cervical spine spares the arms (see Fig. 4.3); lesions above C3 paralyse the diaphragm and are lethal without immediate ventilation (e.g. the ‘hangman’s fracture’; fracture dislocation of C2 on C3).

Figure 4.3 Dermatomes of the body.

Spinal and neurogenic shock

Management

Follow the ATLS primary and secondary survey protocols, maintaining oxygenation and perfusion. Establish whether the cord injury is partial or complete (largely a clinical decision) and whether the vertebral fracture is stable or unstable (requires plain X-rays or CT scanning).

Specialised spinal injury care must be provided as soon as possible; with high quality rehabilitation some useful recovery may be achieved.

History

Establish the type of burn: flame, scald, direct contact, chemical, electrical, radiation. The history will give an idea of the likelihood of inhalational injury and associated carbon monoxide poisoning.

Examination

Area

The ‘rule of nines’ is most convenient (Fig. 4.4). Alternatively the palm of an individual accounts for 1% of their surface area. For infants a Lund–Browder chart is used.

Figure 4.4 Burn assessment, the ‘rule of nines’.

Treatment

Initial treatment is following ABCDE primary and secondary survey protocols. Burns patients are prone to massive fluid loss. The Parkland formula helps guide initial fluid resuscitation:

Half this volume should be given during the first 8 h after the injury. This formula is merely a guide and fluid replacement must be guided by monitoring of cardiovascular status, urine output and U&Es.

Large burns should be covered with clingfilm to reduce fluid loss. Flamazine may ease discomfort and additional analgesia may be needed. A tetanus booster should be given for non-immune patients. Antibiotics are of no benefit at this stage. Subsequent treatment involving surgical debridement, escharotomy, skin grafting and rehabilitation requires a specialist burns unit.