Comparison of target concentration of propofol during three phases of live donor liver transplant surgery using a target-controlled infusion of propofol total intravenous anaesthesia - A prospective, observational pilot study.

Background and aims: Three phases (dissection, anhepatic, and neohepatic) exist for propofol pharmacokinetics during liver transplantation (LT), resulting in varying cardiac output, volume of distribution, and drug metabolism. The primary objective was to compare the mean target concentration of propofol required to maintain the bispectral index (BIS) between 40 and 60 during three phases of LT by using a target-controlled infusion of total intravenous anaesthesia (TCI-TIVA).

Methods: In this prospective, observational study, 20 adult patients diagnosed with chronic liver disease scheduled for live-donor LT were included. After anaesthesia induction and tracheal intubation, BIS-guided propofol infusion was started using TCI-TIVA with target plasma concentration (TPC) set initially at 2.5 μg/mL in all patients using the Marsh model. The TPC was decreased or increased by 0.2 μg/mL whenever the BIS values were persistently below 40 or above 60 for 15 minutes. Data were analysed using ANOVA and repeated measure ANOVA, followed by a post-hoc test.

Results: The mean TPC was significantly higher during dissection [2.12 (Standard deviation (SD): 0.63 μg/mL)] as compared to anhepatic and neohepatic phases [1.29 (SD: 0.65) μg/mL and 1.35 (SD: 0.54) μg/mL], respectively (P < 0.001). A significant difference was observed between dissection and anhepatic (mean difference: -0.87 (95% confidence interval (CI): -0.98, -0.75) or dissection and neohepatic phase (mean difference: -0.77 (95% CI: -1.02, -0.53). The propofol dose was significantly higher in dissection compared to the anhepatic and neohepatic phases (P < 0.001).

Conclusion: The propofol's mean TPC when using TCI-TIVA decreased in the anhepatic and neohepatic phases to 61% and 63.7% of the dissection phase, respectively.