Vecuronium requirements according to the operative phase during living donor liver transplantation under desflurane anesthesia

Introduction: The requirements of nondepolarizing neuromuscular blocking agent during liver transplantation show conflicting results. We sought to evaluate the requirements according to the operative phase and find extrahepatic factors that influence neuromuscular blocking agent requirements. Methods: We enrolled 35 patients undergoing living donor liver transplantation. Continuous infusion of vecuronium was adjusted every 15 minutes for consistent neuromuscular blockade aimed at T1/Tc of 0.10 monitored with a neuromuscular transmission module. We compared the mean infusion dose in each phase, and investigated whether it is correlated with preoperative Model for End-Stage Liver Disease (MELD) score, Child-Turcotte-Pugh (CTP) score, graft-recipient weight ratio (GRWR), or time to recovery of first twitch response to train-of-four (TOF) stimulation. Results: There was a significant difference between vecuronium doses during each phase (P <.001): 0.48 ± 0.16 μg/kg/min, preanhepatic; 0.38 ± 0.14 μg/kg/min, anhepatic and 0.26 ± 0.07 μg/kg/min, neohepatic phase. There was a significant positive correlation between vecuronium infusion dose in the preanhepatic phase and CTP scores (P =.006, correlation coefficient = 0.465). There was also a significant negative correlation between the time to recovery of first twitch response of TOF stimulation and vecuronium infusion dose in the preanhepatic phase (P =.001, correlation coefficient = -0.546). The infusion dose during the preanhepatic phase was not associated with the MELD score, and that of neohapatic phase not with GRWR. Conclusions: The vecuronium infusion dose requirement during the anhepatic decreased compared with that in the preanhepatic phase. It further decreased during the neohepatic phase compared with the previous phases. Vecuronium infusion dose reduction is suggested especially during the neohepatic phase for early extubation. The dose during the preanhepatic phase is suggested to be determined considering the CTP score and the time to recovery of the TOF response.