[Pharmacokinetics of propofol during liver transplantation in small pigs]

A study using 14C propofol showed that the liver is the main eliminating organ for the agent. The current study was designed to clarify pharmacokinetics of propofol during liver transplantation in pigs. Five small pigs weighing 25.4 +/- 2.5 kg were anesthetized with isoflurane (0.5-1.5%) and mechanically ventilated under muscle paralysis with pancuronium. In the anhepatic phase, veno-veno bypass was placed from the inferior vena cava and portal vein to the superior vena cava. We studied pharmacokinetic parameters following an intravenous bolus injection of propofol at 2 mg.kg-1 in each phase, i.e. the pre-anhepatic, anhepatic and post-anhepatic phase during liver transplantation. Pharmacokinetic analysis showed that total plasma clearance of propofol in the anhepatic phase was significantly lower than that in the post-anhepatic phase. The results suggest that propofol may be metabolized extrahepatically and can be used at reduced doses in the anhepatic phase during liver transplantation.