Hepatolobectomy-induced depression of hepatic circulation and metabolism in the dog is counteracted by isoflurane, but not by halothane

Background: The effects of isoflurane and halothane anesthesia on hepatic c irculation and oxygen metabolism during hepatolobectomy were investigated i n the dog, in an attempt to assess which of the anesthetics was the better one for hepatic resection. Methods: Mongrel dogs (n = 24) were divided into two groups and accordingly anesthetized with isoflurane (n = 12) or halothane (n = 12). Each test ane sthetic was administered in air. Electromagnetic flowmeters were used to me asure hepatic arterial and portal venous blood flows 1) before the inhalati on of each anesthetic (baseline); 2) 1 h inhalation of 1.5 MAC (minimum alv eolar concentration) of each anesthetic; and 3) 1 h after hepatolobectomy w ith each anesthesia. Measurements of systemic hemodynamics, blood gas tensi ons, and the arterial ketone body ratio were made at the same time. Results: Isoflurane maintained portal venous, hepatic arterial and total he patic blood flows better than halothane anesthesia before and after hepatol obectomy. With halothane anesthesia, hepatolobectomy decreased prominently hepatic arterial blood flow. Hepatic arterial and mesenteric vascular resis tance increased in the halothane group, but remained constant in the isoflu rane group after hepatolobectomy. Hepatic oxygen delivery was significantly suppressed in the halothane group, but did not change in the isoflurane gr oup. No significant difference was found in hepatic oxygen consumption betw een the two groups, but the arterial ketone body ratio decreased significan tly only in the halothane group before and after hepatolobectomy. Conclusion: The present data indicate that isoflurane has less adverse effe ct than halothane anesthesia on hepatic circulation, oxygen delivery and en ergy charge in hepatolobectomy cases.