Abstract
We evaluated the effecton cerebral oxygen metabolism of various perfusion temperature during cardiopulmonary bypass(CPB). A randomizedtrial comparing among warm (36°C), tepid (33°C) andcold (30°C) perfusion was done in 21 patients With the use of the near-infraredspectroscopy, we monitored the change of oxyhemoglobin (oxyllb) and oxidation lebel of cytochrome oxidase (cyt. aa3). In additionjugular bulb saturation (Sj02), cerebral circulatory index(CCI), lactate extraction ratio and lactate-pyruvate ratio were measured. None hadany neurological complication in this study. During CPB, the oxylb and cyt. aa3 droppedin all groups, while SjO2 aal CCI elevatedin tepid and cold groups. In cold group all parameters indicateddesaturation during rewarming period. Anearobic metabolism representedby change of lactate metabolism deterioratedparallel to operative course, in which we found out no differencesamong groups. These findings suggested that although hypothermia was benefical to cerebral oxygen metabolism, care should be taken to avoid the collapse of oxygen supply /demandrelationship during rewarming.
