Dose requirements and recovery profile of an infusion of cisatracurium during liver transplantation

Abstract

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 T 1 /T 0 to 10%, cisatracurium was infused at an initial rate of 1.5 μ g/kg/min. The infusion rate was adjusted to maintain T 1 /T 0 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 μ g/kg/min. Before the anhepatic phase, this rate was 1.5 ± 0.4 μg/kg/min; during the anhepatic phase it was 1.7 ± 0.5 μg/kg/min; and after reperfusion it was 1.9 ± 0.4 μ g/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 T 1 /T 0 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.