Propofol is used during living-related donor liver transplantation because its metabolism is not greatly affected by liver failure.
However, the pharmacokinetics of propofol during liver transplantation have not been fully defined.
Dr Takiza and colleagues evaluated the apparent systemic clearance of propofol during the dissection.
The researchers also assessed systemic clearance during anhepatic and reperfusion phases of living-related donor liver transplantation.
The team then estimated the role of the small intestine and lung as extrahepatic sites for propofol disposition.
The researchers enrolled 10 patients scheduled for living-related donor liver transplantation were enrolled in the study.
|Apparent systemic clearances in the dissection phase was 1.9 liter per min |
|British Journal of Anaesthesia|
Anaesthesia was induced with vecuronium 0.1 mg kg-1 and propofol 2 mg kg-1.
The anaesthesia was then maintained by 60% air, 0.5-1.5% isoflurane in oxygen and a constant infusion of propofol at 2 mg kg-1 h-1.
Apparent systemic clearance during the dissection, anhepatic and reperfusion phases was calculated from the pseudo-steady-state concentration for each phase.
The researchers determined disposition in the small intestine by measuring arteriovenous blood concentration in 10 liver transplantation donors.
Pulmonary disposition was determined by measuring the arteriovenous blood concentration in 10 recipients during the anhepatic phase.
The team expressed the data as mean results.
Apparent systemic clearances in the dissection, anhepatic and reperfusion phases were 1.9 liter per min, 1.1 liter per min and 1.5 liter per min, respectively.
The researchers observed that the concentration of propofol in the portal vein was lower than in the radial artery.
The team calculated the intestinal extraction ratio from the concentration in the radial artery and portal vein as 0.2.
The researchers noted no significant differences in propofol concentrations between the radial and pulmonary arteries.
Dr Takiza's team concluded, “Apparent systemic clearance was decreased by 10% during the anhepatic phase compared with the dissection phase.”
“After reperfusion, liver allografts rapidly began to metabolize propofol.”
“The small intestine also participates in the metabolism of propofol.”