Study Objective: To examine the dose requirements and recovery profile of an infusion of cisatracurium during liver transplantation.
Design: Open-label, descriptive study.
Setting: University hospital.
Patients: 6 ASA physical status III and IV patients with end-stage liver disease, undergoing liver transplantation.
Interventions: Neuromuscular transmission was monitored electromyographically. After recovery of T1/T0 to 10%, cisatracurium was infused at an initial rate of 1.5 microg/kg/min. The infusion rate was adjusted to maintain T1/T0 at 10%. At the end of surgery, spontaneous recovery from the neuromuscular block was awaited.
Measurements and Main Results: The infusion rate of cisatracurium was 1.6 +/- 0.4 microg/kg/min. Before the anhepatic phase, this rate was 1.5 +/- 0.4 microg/kg/min; during the anhepatic phase it was 1.7 +/- 0.5 microg/kg/min; and after reperfusion it was 1.9 +/- 0.4 microg/kg/min. There was a significant difference between the cisatracurium infusion rates before and after the anhepatic phase (p < 0.05). Following termination of the infusion, the time to 25% recovery of T1/T0 was 19.2 +/- 6.1 minutes, the recovery index (25% to 75%) was 28.8 +/- 7.0 minutes, and the time for the train-of-four (TOF) ratio to reach 0.7 was 50.2 +/- 7.1 minutes. The time for the TOF ratio to reach 0.9 was 61.4 +/- 6.6 minutes. There was no difference in body temperature or pH during the consecutive stages of transplantation.
Conclusions: The infusion dose requirement for cisatracurium during liver transplantation tended to be higher than previously reported in healthy patients; recovery appeared prolonged. In continuous infusion of cisatracurium during liver transplantation, the tendency toward higher dose requirements, the protracted duration of infusion, the non-Hofmann elimination and/or other pharmacokinetic changes during transplantation might influence recovery from the neuromuscular block. Potential temperature or pH change during surgery seemed irrelevant in explaining the delayed recovery.