Abstract: Objective To investigate the effect of different concentrations of sevoflurane inhalation combined with pro⁃ pofol anesthesia on rocuronium pharmacodynamics. Methods Sixty-seven patients, who underwent elective abdominal op⁃ eration in Tianjin Medical University General Hospital from Nov. 2014 to Feb. 2015, were randomly allocated to three groups: propofol combined 0.5 minimum alveolar concentration (MAC) end-tidal concentration of sevoflurane (group Ⅰ , 24 cases), propofol combined 0.75 MAC end-tidal concentration of sevoflurane (group Ⅱ , 20 cases) and propofol combined 1 MAC end-tidal concentration of sevoflurane (group Ⅲ, 23 cases). All those patients were given midazolam 0.05 mg/kg, sufen⁃tanil 0.3 μg/kg, etomidate 0.3 mg/kg for anesthesia induction. Rocuronium was given through the T1 mode of Closed-loop muscle relaxant infusion system and infused by 2ED95（0.6 mg/kg). The following variables were recorded: average consump⁃ tion dosage of rocuronium, recovery index, averaged consumption dosage of propofol and remifentanil. Results The aver⁃ aged consumption dosage of rocuronium was decreased in the three groups in turn[（9.71±2.38 vs 7.50±0.98 vs 6.90±1.14） μg· kg-1· min-1， F=18.562， P < 0.05]. There was no significant difference in recovery index between the three groups [（8.92± 2.62 vs 8.95±2.58 vs 10.30±3.65） min， F=1.577, P > 0.05]. The average consumption dosage of propofol and remifentanil were lower in group Ⅲ than those of group Ⅰ and group Ⅱ (P < 0.05). Conclusion High concentration of sevoflurane can enhance neuromuscular blockage effect of rocuronium, and decrease the consumption dosage of propofol and remifentanil

Key words: Sevoflurane, Propofol, Rocuronium, Pharmacodynamics, Closed-loop muscle relaxant infusion system