The definitive management of these patients is beyond the scope of this article, but some basic points can be reviewed. Many hospitals in the world do not have access to neurological services such as Computerised Tomography (CT) scanning. None the less, much can be achieved. In a review of severely head injured patients in hospitals in the developing world without access to CT scan or a neurosurgeon , 25% of a series of 214 severely head injured patients (Glasgow Coma Scale 8 or less) made a good recovery.

As with all trauma patients, the treatment of those with head injuries is dependant on the principle that no further damage should occur to the injured brain after the initial trauma. Any process resulting in inadequate brain perfusion may cause a secondary brain injury, and hypoxia, hypercarbia and hypotension must be prevented. The primary survey and secondary survey will help to detect these problems. The Airway, Breathing and Circulation should be assessed and treated appropriately, the nervous system surveyed and the entire patient examined.

Assessment: Obviously, injuries to the head such as lacerations, bruising or evidence of fractures raises the possibility of an intra-cranial injury, but the presence of a head wound is not necessary for a serious injury to exist. If present wounds should be gently explored and documented. Dysfunction of the nervous system during the primary and secondary survey is assessed. A trend of clinical signs is useful and can be recorded on an appropriate chart ( figure 9). This may be downloaded if required and used in your hospital ( Acrobat file, Size:79K).

A difficult problem in many trauma cases is differentiation between those patients who have a depressed conscious level due to cardiorespiratory problems and those who have a brain injury. It is also important to decide which patients require neurosurgical intervention. Although detailed examination, repeated observations and skull radiographs may help, the majority of seriously head injured patients undergo CT scanning in the developed world to assess the need for surgery. CT's reveal intracranial haemorrhages, cerebral oedema, midline shift and mass effect. They do not , however, show many changes in those patients with diffuse axonal injury. CT scans may give a false sense of security if performed soon after the traumatic event (up to 6 hours). The vast majority of patients going for CT scanning will require intubation and ventilation and this should be performed in a suitable area before transferring the patient.

Treatment: significant extradural and subdural haematomas require urgent evacuation. In units far from a neurosurgical centre, the general or orthopaedic surgeons must perform the necessary procedure. Where no CT facilities exist clinical indications of an intracranial haematoma in a patient with a head injury include a decreasing level of consciousness and a dilated pupil on the same side as the haematoma and less limb movement on the opposite side.

Management of patients with serious head injury is somewhat controversial. In most units in the UK, a period of sedation and controlled ventilation is undertaken. This allows a period of stability to be attained and cerebral oxygen delivery to be optimised, but it prevents serial measurements of the patient's level of consciousness. Each case must therefore be considered on its own merits. Controlled ventilation should be performed to treat hypoxia, repeated vomiting, agitation, fitting or evidence of raised intracranial pressure (ICP).

Raised ICP is suggested by a Glasgow Coma Scale of less than 8, slow pupillary responses to light, respiratory rate abnormalities, hypertension and bradycardia. The most reliable method of evaluating the ICP is to measure it directly, although there is no clear evidence that outcome is improved and many hospitals in UK do not routinely measure ICP in head injuries. Several methods are available including the intraventricular, subdural, extradural and intra-parenchymal monitors but none are commonly available in developing countries. They also have a significant complication rate due to bleeding, infection and brain injury.

When treating head injuries ensure that conditions predisposing to rises in intracranial pressure are managed properly. Therefore pain, fever, bladder distension, hyponatraemia, hypoxia, hypercapnia, hyperglycaemia and hypertension must all be treated. The patient should be nursed with a slight head -up tilt and endotracheal tubes must be taped (not tied) to encourage cerebral venous drainage. Raised intrathoracic pressure and rigid cervical collars also may impede venous return and ventilation patterns should be tailored individually. Sandbags, headtapes or external fixation e.g. calipers should be considered in the presence of a cervical spine injury. Coughing should be avoided, and therefore neuromuscular blockade may be required provided the patient is adequately sedated.

Once these general causes have been treated, any deterioration warrants consideration for repeat CT scan if this is available. The presence of a significant haematoma needs evacuation. Cerebral oedema is often treated with mannitol in order to increase the osmolarity of the blood. In the trauma setting, however, the blood-brain barrier may be disrupted allowing leakage of the mannitol thereby exacerbating the problem. It should therefore be used with care. Drainage of CSF may help to reduce ICP but requires an intraventricular catheter. Intracranial pressure can also be reduced temporarily by hyperventilation which results in cerebral vasoconstriction and thereby a reduction in intracranial blood volume. However, this effect only lasts for about 12 hours by which time homeostatic mechanisms reset themselves. Theoretically hyperventilation can also induce cerebral hypoxia, and most centres now ventilate patients to obtain a pCO₂ in the low-normal range. Cerebral blood volume can also be reduced indirectly by reducing the cerebral oxygen consumption. This is the rationale for the treatment of a raised temperature (and in some centres, the induction of mild hypothermia) and therapy with barbiturates. Although the latter decrease ICP, there is little evidence to confirm their effectiveness. If required, controlled ventilation is usually instituted for a period of 24 - 48 hours. If the patient is stable after this time, sedation may be stopped and the patient assessed. Re-sedation and ventilation may be required if neurological function is poor.

During the patient's hospital stay the head injury must not lead to inadequate holistic care. Attention must therefore be made to analgesia, prevention and treatment of infection, nutrition and physiotherapy.

Poor recovery from head injury often overwhelms the family caring structure, and rehabilitation should be organised at the earliest opportunity. Apparent recovery may mask more subtle psychological defects, and therefore all patients recovering from severe head injuries must be assessed appropriately.

(Continued...)

---

©World Federation of Societies of Anaesthesiologists WWW implementation by the NDA Web Team, Oxford

---