Comparative Study of Neuromuscular Blocking and Hemodynamic Effects of Rocuronium and Cisatracurium Under Sevoflurane or Total Intravenous Anesthesia

Neuromuscular blockers (NMB) are important adjuvant to general anesthesia, rocuronium bromide and cisatracurium besylate are considered relatively recently introduced nondepolarizing muscle relaxants. Objectives: This study evaluates the enhancement of cisatracurium and rocuronium -induced neuromuscular block during anesthesia with 1.5 MAC sevoflurane or total i.v. anesthesia (TIVA), hemodynamic effects and side effects. Methodology: 80 patients were randomly allocated into one of four equal groups to receive either rocuronium (under sevoflurane or propofol TIVA) or cisatracurium (under sevoflurane or propofol TIVA). The NMB effects of rocuronium and cisatracurium were studied by constructing dose-effect curves. Acceleromyography (TOF-Guard) and train-of-four (TOF) stimulation of the ulnar nerve were used (2Hz every 15sec.). Cisatracurium and rocuronium were administered in increments until depression of Tj/Tq 95% was reached. Hemodynamic effects of both muscle relaxants together with sevoflurane or propofol were assessed using thoracic bioimpedance. Results: Depression of Tj/Tq was enhanced under sevoflurane compared to TIVA . ED50 and ED 95 values of both drugs were significantly lower under sevoflurane more than TIVA . Recovery index 25-75% and time to a TOF ration of 0.70 were prolonged significantly by sevoflurane compared to TIVA . Hemodynamically, rocuronium and cisatracurium did not exert significant changes, but the interaction of the relaxants and the anesthetic agents resulted in statistically significant decline in some hemodynamic parameters at certain periods which are not clinically significant and required no medications. Conclusion: We conclude that the effects of rocuronium and cisatracurium are significantly enhanced during sevoflurane compared with propofol anesthesia and the recovery is slower.