Chapter 66 Severe and multiple trauma
Trauma can be defined as physical injury from mechanical energy. It is usually categorised as blunt or penetrating. In Western countries, severe blunt trauma is common, caused by road crashes, falls and, less frequently, blows and assault. Severe penetrating trauma, usually from stabbings and gunshots, is less common except in larger cities of the USA,1,2 South Africa and war zones. Blunt trauma is often more difficult to treat than penetrating trauma. Assessment is more difficult, because injuries are frequently internal, multiple and not obvious initially. The risk of missing serious injuries can only be lessened by a systematic approach and repeated assessments.3–5
ASSESSMENT AND PRIORITIES
TRIAGE
BASIC TREATMENT PRINCIPLES
A systematic approach to managing severe and multiple trauma is important. Effective programmes developed by the American College of Surgeons are now well established.6 A number of basic treatment principles apply to all severe trauma patients.
EMERGENCY ASSESSMENT (PRIMARY SURVEY)
The following must be recognised and treated before anything else:
OXYGEN AND VENTILATORY THERAPY
High-flow oxygen by mask is given to all trauma patients. However, patients with severe trauma frequently require ventilatory support. A restless uncooperative patient should be intubated under a rapid sequence induction to facilitate resuscitation.
BLOOD CROSSMATCH AND TESTS
Six units of red cells should be crossmatched urgently, but it is impossible to predict the amount of blood that will be required. Blood is concurrently sent for baseline haematological and biochemical tests, including blood ethanol level. Blood ethanol is clinically useful in assessing individual patients with depressed consciousness, quite apart from epidemiological and preventive medicine,7 and legal considerations.
CLINICAL EVALUATION OF INJURIES (SECONDARY SURVEY)
Injuries are easily missed in an emergency, especially when one injury is obvious. A secondary, and even a tertiary, survey should be performed.5 The back and the front of the patient should be examined. Special attention is paid to regions with external lacerations, contusions and abrasions. All body regions are examined systematically.
FACE
Bleeding into the airway should be excluded, and the face and jaws tested for abnormal mobility.
THORAX
Fractured ribs in themselves are not usually life-threatening but haemothorax, pneumothorax, lung contusion and chest wall instability (flail chest) will require attention if present. Less common but very serious injuries can occur to the heart and great vessels (see Chapter 69).
ABDOMEN
The spleen, liver and mesenteries are often damaged. Retroperitoneal haemorrhage is common. Injuries to the pancreas, duodenum and other hollow viscera are less frequent, and may be missed until signs of peritonitis occur. Renal injury with retroperitoneal haemorrhage is suggested by haematuria and loin pain (see Chapter 71).
SHOCK IN THE TRAUMA PATIENT
HYPOVOLAEMIC SHOCK
If the neck veins are empty, hypovolaemic shock should be inferred. Possible sites of blood loss causing shock are:
NEUROLOGICAL SHOCK
Patients with paraplegia or tetraplegia from spinal cord injury may have low blood pressure with warm dilated peripheries accompanied by lax anal tone and by priapism in the male (see Chapter 70). This is a diagnosis of exclusion and all causes of hypovolaemic shock (see above) must be sought.
ABDOMINAL ULTRASOUND
Its main usefulness is probably in the unstable patient when it is positive, to indicate the need for laparotomy without the necessity to proceed to diagnostic peritoneal lavage (DPL).9 FAST scans performed by enthusiastic amateurs in emergency departments without a treatment algorithm can be misleading and therefore worse than useless.
DIAGNOSTIC PERITONEAL LAVAGE
Diagnostic peritoneal lavage is indicated to diagnose intra-abdominal bleeding
Caution is needed with pregnancy, previous abdominal surgery or massive pelvic injury. Isotonic saline 1 l (or 10 ml/kg) is instilled into the peritoneal cavity, after drainage of the stomach and bladder. The presence of more than 10 ml frank blood on catheter aspiration necessitates immediate laparotomy; otherwise a lavage fluid specimen should be examined for red and white cell counts and amylase concentration. A red cell count over 100 000 per mm3, white cell count over 500 per mm3, or an increased amylase concentration suggests bleeding or viscus injury, and laparotomy should be undertaken immediately. These absolute figures are debatable and lower values are accepted in penetrating trauma.6,10 Peritoneal lavages inevitably result in some false-positive laparotomies. However, in severe trauma, morbidity of a non-therapeutic laparotomy (i.e. no definitive surgery) is small compared with the dire consequences of missing significant intra-abdominal injury.11
CT ABDOMEN
Abdominal CT is not indicated in shock, but can be useful in the stable patient. Improved availability of CT scanning, and technological advances with reduced scanning times and better definition, is increasingly favouring CT abdomen over DPL in patients who are sufficiently stable to tolerate the procedure safely. It needs to be performed quickly and safely, with gastric and i.v. contrast, and interpreted by radiologists experienced in trauma. Visualisation of abdominal and pelvic organs and haemorrhage is excellent,12,13 but results can be misleading and disastrous with poor technique.4