Effects of enflurane and halothane on liver blood flow and oxygen consumption in the greyhound

The effects of increasing inspired concentrations of halothane 0.5, 1.0, 1.5, 2.0% and enflurane 1.0, 1.5, 2.0, 3.0% on the hepatic circulation, were investigated in two groups of anaesthetized greyhounds. Hepatic arterial and portal venous blood flow were measured continuously using electromagnetic flow probes. Mean arterial pressure and cardiac output were monitored throughout each investigation. At equipotent anaesthetic concentrations there were similar and dose-dependent decreases in hepatic arterial, portal venous and total liver blood flows in both groups. Enflurane produced a more marked decrease in mean arterial pressure than halothane because of a significant decrease in systemic vascular resistance. Hepatic arterial resistance decreased significantly with enflurane but was unchanged in the group receiving halothane. Neither drug affected hepatic oxygen consumption significantly.