[Blood concentration of propofol during cardiopulmonary bypass--comparison between arterial and internal jugular...

Twelve adult patients for cardiac surgery were divided into 2 groups, normothermia (6 patients) and mild hypothermia (6 patients), based on their body temperature during cardiopulmonary bypass (CPB). Propofol was continuously administered throughout each operation at a dose of 2 mg.kg-1.h-1. Arterial and internal jugular venous bulb blood samples were drawn simultaneously before CPB, at 5, 30, 60, and 90 minutes after the start of CPB, 30 minutes after the end of CPB, and at the conclusion of the operation, to measure propofol concentrations. In the normothermia group, propofol concentration in the arterial blood decreased significantly 5 minutes after the start of CPB, and then recovered immediately to the pre-CPB value. In the mild hypothermia group, however, no significant change in propofol concentration was observed. In both groups, there was no significant difference in propofol concentration between arterial and internal jugular venous bulb blood throughout the study period. Our results suggest that there are no significant differences between the effect of normothermic and that of mild hypothermic CPB on the pharmacokinetics of propofol in the brain.