Delayed pentobarbital therapy of acute focal cerebral ischemia.

The efficacy of pentobarbital in the delayed treatment of acute cerebral ischemia was investigated in cats. Cerebral ischemia was produced by left middle cerebral artery (LMCA) ligation. Ten cats received 50 mg/kg of pentobarbital prior to ligation; a second group of 10 cats received the same dose of pentobarbital 2 hrs after ligation, and the control group of 7 cats received no pentobarbital. Brains were removed after spontaneous or induced death and the volume infarction was determined histologically. It was found that the volume of brain infarction in the group receiving pentobarbital 2 hrs after ligation was significantly less than that of the control group, which received no pentobarbital; but the volume of infarction in the former group was significantly greater than that found in the experimental group, which received pentobarbital prior to ligation. However, the mortality after LMCA ligation was higher in the 2 experimental groups, which received pentobarbital therapy, than in the control group, which did not receive pentobarbital. An hypothesis was advanced, which speculated that secondary adrenal insufficiency and altered cardiovascular function accounted for the increased mortality after pentobarbital treatment of patients with ischemic stroke.