Optimizing Propofol Dosing for Liver Transplantation: Study suggests Phase-Specific Adjustments for Safe Anesthesia Management

Propofol has proven effective in liver transplantation procedures for both initiating and sustaining anesthesia. Compared to inhalational anesthetics, it offers superior hemodynamic stability. In addition to its anti-inflammatory and free radical scavenging attributes, propofol safeguards against ischaemia-reperfusion injury, offering protections to the liver, heart, kidneys, and nervous system. Recent study examined the changes in the target concentration of propofol required to maintain the bispectral index (BIS) between 40 and 60 during the three phases of liver transplantation.

The researchers used a target-controlled infusion of total intravenous anesthesia (TCI-TIVA) and found significant differences in the mean target propofol concentration between the dissection, anhepatic, and neohepatic phases. The study was a prospective, observational pilot study conducted on 20 adult patients diagnosed with chronic liver disease who were scheduled for live-donor liver transplantation. After anesthesia induction and intubation, a BIS-guided propofol infusion was started using TCI-TIVA with an initial target plasma concentration (TPC) of 2.5 μg/mL.

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. The results showed that the mean TPC was significantly higher during the dissection phase \[2.12 (SD: 0.63 μg/mL)\] compared to the anhepatic \[1.29 (SD: 0.65) μg/mL\] and neohepatic \[1.35 (SD: 0.54) μg/mL\] phases (p<0.001). There was a significant difference between the dissection and anhepatic phases (mean difference: -0.87 μg/mL, 95% CI: -0.98, -0.75) and the dissection and neohepatic phases (mean difference: -0.77 μg/mL, 95% CI: -1.02, -0.53), but not between the anhepatic and neohepatic phases.

Dosage Comparison

The propofol dose was also significantly higher in the dissection phase compared to the anhepatic and neohepatic phases (p<0.001). The propofol's mean TPC decreased to 61% and 63.7% of the dissection phase levels during the anhepatic and neohepatic phases, respectively.

Conclusion

The authors concluded that the propofol target concentration should be adjusted to 61% and 63.7% of the dissection phase levels during the anhepatic and neohepatic phases, respectively, to avoid overdosage and ensure optimal anesthesia management. The study highlights the importance of tailoring propofol dosing to the different phases of liver transplantation to maintain appropriate anesthetic depth.

Key Points

1. The study examined the changes in the target concentration of propofol required to maintain the bispectral index (BIS) between 40 and 60 during the three phases of liver transplantation using target-controlled infusion of total intravenous anesthesia (TCI-TIVA).

2. The study found significant differences in the mean target propofol concentration between the dissection, anhepatic, and neohepatic phases, with the mean target propofol concentration being significantly higher during the dissection phase compared to the anhepatic and neohepatic phases.

3. The propofol dose was also significantly higher in the dissection phase compared to the anhepatic and neohepatic phases, with the propofol's mean target plasma concentration (TPC) decreasing to 61% and 63.7% of the dissection phase levels during the anhepatic and neohepatic phases, respectively.

4. The authors concluded that the propofol target concentration should be adjusted to 61% and 63.7% of the dissection phase levels during the anhepatic and neohepatic phases, respectively, to avoid overdosage and ensure optimal anesthesia management.

5. The study highlights the importance of tailoring propofol dosing to the different phases of liver transplantation to maintain appropriate anesthetic depth.

6. The study was a prospective, observational pilot study conducted on 20 adult patients diagnosed with chronic liver disease who were scheduled for live-donor liver transplantation.

Reference –

Garg N, Kalra Y, Panwar S, Arora MK, Dhingra U. 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. Indian J Anaesth 2024;68:971‑7