Cardiovascular effects of enflurane and halothane on the rhesus monkey

Ten rhesus monkeys were chronically instrumented to compare the cardiovascular effects of enflurane and halothane. In 17 experiments, each monkey was evaluated in the awake state and after equilibration at each of many anesthetic levels. End-expired gas concentrations were expressed in multiples of human minimum alveolar concentrations (MAC) for comparison. There was a predictable dose-related decrease in heart rate, mean arterial pressure, peak left ventricular dp/dt, and the latter divided by left ventricular developed pressure (see article) with both agents. Central venous pressure was increased by both. At equal MAC levels, no significant differences were detected between halothane and enflurane. Cardiac output and aortic flow acceleration were obtained on one of the animals for both agents. Results were consistent with those for the other measured parameters.