1996 OPEN FORUM Abstracts
Cerebral Resuscitation and the Head-Injured Patient
John M. Luce, MD Tuesday, November 5, 1996
Head injury causes diffuse or mass lesions; among the latter are cerebral contusion, epidural hematoma, subdural hematoma, and intracerebral hematoma. Both diffuse and mass lesions may cause an increase in intracranial pressure (ICP > 10 mm Hg), which can result in displacement of brain tissue and alterations in cerebral blood flow. CBF is equal to cerebral perfusion pressure [Mean arterial pressure (MAP)-ICP] divided by cerebral vascular resistance. CBF also is affected by changes in PaCO_{2} and PaO_{2}. The respiratory effects of head injury may include neurogenic pulmonary edema, aspiration, and pneumonia. Cardiovascular effects include possible hypotension or hypertension. Metabolic effects include an increased resting metabolic expenditure and nitrogen production. The initial evaluation of head injured patients includes radiographic studies and use of the Glasgow Coma Scale. Monitoring is accomplished by repeated physical examinations, measurement of cerebral perfusion pressure, and measurement of cerebral arteriovenous oxygen differences. ICP may be reduced by increasing cerebral venous drainage, hyperventilation, hyperosmolar agents, diuretics, cerebrospinal fluid drainage, and surgical decompression. Drug therapy has not proven helpful. Prognosis can be estimated by age, clinical presentation, type of injury and ICP. Therapy also may affect outcome, but this has not been demonstrated in prospective, randomized trials.