Cardiovascular effects of propofol and of thiopentone anaesthesia in the sheep

Abstract

We have examined the effects on the cardiovascular system and on regional blood flow of propofol and thiopentone when administered with IPPV (FlO2 0.4). A longitudinal study design was used in which 16 studies were performed in eight sheep for 30 min before, during the last 30 min of 70 min anaesthesia, and for 6 h after anaesthesia. During anaesthesia with propofol and thiopentone, mean total body oxygen consumption decreased, respectively, by 47% (P < 0.001) and 24% (P < 0.01) of pre-anaesthesia baseline values, mean heart rate increased by approximately 50% (P < 0.05) with both agents, mean arterial pressures increased by approximately 50% (P < 0.05) with both agents and the mean cardiac output was unaltered with propofol anaesthesia but was decreased by 20% (P < 0.05) with thiopentone anaesthesia. The changes in arterial pressure and heart rate were unexpected and may have been a result of a species-specific effect. Mean hepatic blood flow decreased consistently by a mean of 17% (P < 0.01) during propofol anaesthesia, and inconsistently during thiopentone anaesthesia so that it was not significantly different from baseline values. Mean renal blood flow decreased during propofol anaesthesia by 7% (P < 0.05) and by 27% (P < 0.001) during thiopentone anaesthesia. Whereas most variables returned to baseline values within 2 h after propofol anaesthesia, this took 5 h after thiopentone anaesthesia. © 1990 Copyright: 1990 British Journal of Anaesthesia.