Barbiturate-induced coma to protect against cerebral ischemia and increased intracranial pressure.

The use of barbiturates to induce coma as a means of extending the period of reversible cerebral ischemia is reviewed. Barbiturate use in patients who had had strokes or were undergoing aneurysm surgery was initially encouraging. In uncontrolled feasibility trials in patients with cardiopulmonary arrest or in deep coma, 40 patients received 10 mg/kg thiopental sodium by i.v. push followed by 20 mg/kg thiopental sodium i.v. over the next 30 minutes; 60% of these patients regained consciousness. In a subgroup of 22 patients who had ischemia normally associated with a 90% mortality rate, 14 recovered completely. In the largest clinical trial, 45 patients with severe head injury and elevated intracranial pressure received 3--5 mg/kg pentobarbital over 10--20 minutes. A serum barbiturate level of 2.5--4.0 mg/dl was maintained for 14 days, and 30% of these patients recovered but with neurologic deficits. Other results in stroke and drowning victims were not as encouraging. It is concluded that barbiturate therapy is beneficial in the lowering of intracranial pressure. Focal and global cerebral ischemia have been shown amenable to barbiturate therapy in isolated cases. The prophylactic use of barbiturates in surgical procedures requiring focal cerebral anoxia appears to be beneficial. Controlled trials of the use of barbiturate-induced coma are clearly indicated.