Effect of Nimodipine, Phenylephrine, Pentobarbital, and Ketamine on Cerebral Energy Metabolism in Cerebral Air Embolized Cats: in vivo 31 P Nuclear Magnetic Resonance Spectroscopy Study / 대한마취과학회지

ABSTRACT

The author used in vivo P nuclear magnetic resonance spectroscopy to determine the effect of cerebral air embolization and nimodipine, phenylephrine, pentobarbital and ketamine on changes of pH and PCr/Pi in 35 cats After anesthetizing animals by 15mg/kg/hr iv of pentobarbital in control, nimodipine, nimodipine plus phenylephrine and phenylephrine group or 6 mg/kg/hr of ketamine iv in ketamine group, air was introduced into the carotid artery and 10 ug iv of nimodipine every 6 min or 0.1% phenylephrine iv infusion to maintain mean arterial blood pressure were given. There were tendencies that mean arterial blood pressure increased immediately after infusion of air and recovered baseline value in phenylephrine, nimodipine plus phenylephrine and ketamine groups but remained lower than baseline vaIue in pentobarbital and nimodipine group(P<0.05). The pH decreased in 6 min and returned to baseline within 24 min in all groups and PCr/Pi decreased in all cats in 6 min and recovered baseline value but remained low values in control and nimodipine group without statistical significance. The results suggest that cerebral ischemia by air embolism was aggravated by vasodilating and hypotensive action of nimodipine and was ameliorated by maintaining or elevating blood pressure by phenylephrine, and also ketamine anesthesia showed faster recovery of brain metabolism than pentobarbital anesthesia, but these findings were only the tendencies and further study is recommended.