식염수로 선택적 뇌관류시 관류액의 온도에 따른 평탄뇌파의 출현 시기

Abstract

Cerebral metabolism can be divided into basal and active metabolism. Active electroencephalo-gram(EEG) represents electrophysiologic activity of the brain and become flat when such an activity is abolished. Hypothermia can protect ischemic cerebral damage by reducing cerebral metabolic rate. Profound hypothermia could induce a slow or flat EEG. It can be assumed that the cessation of brain electrical activity appear far faster in the case of cerebral ischemia combined with brain cooling than simple ischemia. To prove this assumption, we carried out this study to determine if selective brain cooling shortens time to onset of a flat electroencephalo-gram(EEG) after cerebral ischemia. Rabbits were anesthetized with halothane and oxygen. Brain was selectively cooled by intracarotid infusion with saline at 371C (normothermic group) and 18°C (hypothermic group). Cerebral ischemia was induced for 2 minutes with a simultaneous clamping of contralateral carotid artery and induced hypotension. In 22 of 28(79%) episodes a flat EEG was identified, and occurred an average 10土 1 sec in the hypothermic group, 14土1 sec in the normothermic group. Time to onset of a flat EEG was significantly faster in the hypothermic group than normothermic group(p=0.02). These patterns may be recognized as an indication of metabolic suppression of hypothermia during cerebral ischemia. (Korean J Anesthesiol 1995; 29: 173ᅳ178)