Cardiovascular interaction between sevoflurane and nicardipine in open chest dogs

Cardiovascular interaction between nicardipine and sevoflurane was examined in dogs and compared with nicardipine-thiopental interaction and nicardipine-halothane interaction. The bolus intravenous injection of nicardipine at dosages of 15 micro g/kg and 30 micro g/kg under sevoflurane anesthesia produced transient decreases in blood pressure, systemic vascular resistance, left ventricular pressure, left ventricular (dp)/(dt) and -(dp)/(dt), and a slight increase in cardiac output. The degrees of these changes were almost identical to those under thiopental or halothane anesthesia. Left and right atrial pressure, pulmonary arterial pressure, pulmonary vascular resistance were not changed by nicardipine under any of the three anesthetics. These results suggest that the cardiovascular interaction of nicardipine and sevoflurane is additive and similar to that of nicardipine and halothane and that the cardiovascular changes induced by nicardipine are not modified by the presence of anesthetics.