The Association Between Intraoperative Objective Neuromuscular Monitoring and Rocuronium Consumption During Laparoscopic Abdominal Surgery: A Single-Center Retrospective Analysis

Background: Rocuronium consumption with or without intraoperative objective neuromuscular monitoring in clinical settings of unrestricted use of sugammadex and neuromuscular monitoring has not been reported. The aim of the study was to investigate the association between the use of intraoperative objective neuromuscular monitoring and rocuronium consumption in patients undergoing laparoscopic abdominal surgery.Methods: Data were collected by reviewing electronic medical records of patients who received laparoscopic abdominal surgery under general anesthesia with rocuronium and reversal with sugammadex at Asahikawa Medical University Hospital between May 2017 and April 2018. Multiple linear regression model was developed to compare the amount of rocuronium consumption per weight per hour (mg/kg/h) between the group in which intraoperative objective neuromuscular monitoring was used (NM+ group) and the group in which intraoperative neuromuscular monitoring was not used (NM- group). Additionally, we performed an interaction test with reference to the results of the subgroup analysis.Results: A total of 429 patients were evaluated, with 371 patients (86%) included in NM+ group and 58 patients (14%) in NM- group. In the NM+ group, 94% of the patients received additional rocuronium after reappearance of TOF response while 6% of the patients received additional rocuronium before reappearance of TOF in order to maintain post-tetanic count. Log-transformed rocuronium consumption between NM+ group and NM- group was not significantly different (back-transformed β-coefficients [95%CI]: 1.054 [0.946–1.174]; P=0.34). Male sex and body mass index (BMI) were independent factors associated with 15% (0.854 [0.789–0.925]; P2 increase in BMI) (0.970 [0.962­–0.979]; Pβ: 0.843 [0.759–0.936]; P=0.001).Conclusions: This single center retrospective study demonstrated that although the use of intraoperative objective neuromuscular monitoring was not an individual factor influencing intraoperative rocuronium consumption, the use of intraoperative neuromuscular monitoring reduced rocuronium consumption by approximately 15% during laparoscopic abdominal surgery in elderly patients.