Comparison of the Effects of Remimazolam and Propofol, With Epinephrine-containing Lidocaine, on Rocuronium-induced Muscle Relaxation

Objective: This study aimed to compare the effects of remimazolam and propofol on neuromuscular blockade induced by the nondepolarizing neuromuscular blocking agent (NMBA) rocuronium and to evaluate the additional influence of epinephrine-containing lidocaine administered as a local anesthetic during general anesthesia. Methods: A total of 38 patients undergoing Le Fort I osteotomy were randomly assigned to the remimazolam group (R group) or propofol group (P group). All patients also received remifentanil and rocuronium. The rocuronium infusion rate was adjusted to maintain a train-of-four (TOF) ratio of 30% ± 10% and recorded. After administering the local anesthetic solution (2% lidocaine containing 1:80,000 epinephrine), the TOF ratio was recorded every minute for 20 minutes. Results: The mean (SD) continuous infusion rate of rocuronium required to maintain a similar TOF ratio was significantly smaller in R group (5.3 (0.5) µg/kg/min) than in P group (6.5 (0.8) µg/kg/min; P < .001). The mean (SD) TOF ratio before administering the epinephrine-containing lidocaine was 26.4% (11.8%) in P group and 30.1% (11.8%) in R group (P = 1.0) and after administration was 7.5% (7.8%) in P group and 8.3% (10.1%) in R group (P = 1.0), all of which lacked statistical significance. Conclusion: Our results suggested that remimazolam and epinephrine-containing lidocaine administered for local anesthesia enhanced the NMBA effect of rocuronium.