Effects of Propofol and Halothane on Cerebral Metabolism and Brain Histopathologic Change Following Complete Cerebral Ischemia in Diabetic Rabbit

Abstract

Background : Because propofol has cerebral effects similar to barbiturates, it is postulated that propofol might offer more protection than halothane during cerebral ischemia. But there is no consistent data on the protective difference between these two agents. So this study was done to evaluate the cerebral protective effect of propofol and halothane on the diabetic model which is more susceptible to ischemic insult. Methods : Twenty diabetic rabbits were anesthetized with 1% halothane in O2 and N2O. In propofol group (n=10), halothane was discontinued and intravenous infusion of 1% propofol was started (loading dose: 1.6 mg/kg/min, maintenance dose: 1.2 mg/kg/min) and the remainder rabbits served as halothane group (n=10). Thirty minutes after propofol infusion (same waiting interval in halothane group) cerebral ischemia was produced by combination of around neck tourniquet inflation and systemic hypotension for 10 minutes. Periischemic vital signs, arterial and internal jugular venous gas analysis, glucose and lactate concentrations were measured. Brain histopathologic examination was done with light microscope after reperfusion. Results : The vital signs, glucose concentrations, arterial blood gas analysis and brain histopathologic examnination were not differed between these two groups in periischemic period. During the reperfusion period, the venous blood pH, PCO2, oxygen contents and lactate concentrations were more rapidly returned to preischemic value in propofol group. Also the arterial blood pH and arteriovenous oxygen content differences were more rapidly returned to preischemic value in propofol group during the reperfusion period. Conclusions : This results suggest that propofol has more cerebral protective effect from complete cerebral ischemia in diabetic rabbit compared to halothane. (Korean J Anesthesiol 1997; 32: 902∼912)