[Effects of cardiopulmonary bypass on hepatic circulation and hepatic oxygen metabolism under fentanyl anesthesia in beagles].
Disturbances of hepatic blood flow (HBF) and hepatic oxygen metabolism (HMO) have been reported in patients and animals undergoing cardiopulmonary bypass (CPB). In the present study, we examined changes of HBF and HMO during CPB in eight beagles (13.5 +/- 2.4 kg). Hepatic arterial blood flow (HABF) and portal venous blood flow (PVBF) were measured with an electromagnetic flowmeter before CPB, during normothermic CPB, during hypothermic CPB under 10 micrograms.kg-1.h-1 of fentanyl anesthesia. CPB was conducted with membrane oxygenation and a non-pulsatile pump flow of 2.4 l.min-1.m-2. Hepatic oxygen delivery (HDO2) and consumption (HVO2) were calculated from HBF and oxygen content in arterial, portal venous and hepatic venous blood. Hepatic energy charge (HEC) was also assessed by measuring the arterial ketone body ratio (AKBR). HABF was unchanged during CPB, but PVBF decreased during normothermic CPB. Total hepatic blood flow decreased during normothermic and hypothermic CPB. HDO2 decreased during CPB because the oxygen content in the arterial and portal venous blood decreased. However, HVO2 was well maintained by spontaneous rises in oxygen uptake ratio despite the decrease in HDO2. The AKBR remained above 0.8 during CPB. Our results indicate that the CPB technique in the present study decreased HBF, but did not cause any adverse effects on HOM or HEC.
Koizumi
M
M
Department of Anesthesiology, Saitama Medical School.
D000771:Anesthesia, Intravenous; D018686:Anesthetics, Intravenous; D000818:Animals; D002315:Cardiopulmonary Bypass / Q000009:adverse effects; D004285:Dogs; D004734:Energy Metabolism; D005283:Fentanyl; D008099:Liver / Q000378:metabolism*; D008102:Liver Circulation; D010101:Oxygen Consumption
D018686:Anesthetics, Intravenous; D005283:Fentanyl