The effects of dose response of sevoflurane and isoflurane on pharmacodynamics of Rocuronium

Objective:To observe the effects of dose response of sevoflurane and isoflurane on pharmacodynamics of Rocuronium.Methods: Fifty six ASA classⅠ~Ⅱ otorhinolaryngology patients were randomly allocated to group P(maintained by propofol);group S1,S2,S3 and I1,I2,I3 end-expiratory concentrations of sevoflurane and isoflurane were maintained by 0.4MAC,0.7MAC and 1MAC respectively.Anesthesia was induced by midazolam,propofol and fentainyl and maintained by propofol and a continuous infusion of 0.1-0.2μg·kg-1·min-1 in group P,In group S1,S2,S3 and I1,I2,I3,the anesthesia was maitained by sevoflurane and isoflurane inhalation of 0.4MAC,0.7MAC and 1MAC respectively and a continuous infusion of remifentainl 0.1-0.2μg·kg-1·min-1 altogether.A bolus dose of Rocuronium of 0.6 mg·kg-1 was administered after end-expiratory concentration of sevoflurane or isoflurane was stable for 40 min.Acceleromyography(TOF-Watch SX) and train-of-four(TOF) stimulation of the ulnar nerve were used(2 Hz every 15 s),the onset time,clinical during time and recovering index was recorded.Results: The onset time was significantly shorter in S2,S3 and I2,I3 group than that in group P(P0.05),and the during time and recover index were significantly longer in group S2,S3 and I2,I3 than that in group P(P0.05).Compared to S2,the onset time was significantly shorter and the during time and recover index were significantly longer in S3 and I3 in group(P0.05).Conclusion: More than 0.7MAC end-expiratory concentration of sevoflurane can strengthen pharmacodynamics rocuronium and with the concentration of sevoflurane inhalation rise,the pharmacodynamics of rocuronium becomes stronger.