Pharmacodynamic Study on Cisatracurium and Rocuronium

OBJECTIVE To investigate the effect of a precurarizing dose of cisatracurium and rocuronium with a priming time of 3 min on decreasing the onset time of cisatracurium for tracheal intubation,and determine the duration and recovery profile of maintenance doses of cisatracurium following rocuronium.METHODS A total of 160 patients with ASA Ⅰ-Ⅱ scheduled for elective surgery were randomized into 4 groups.The patients in group Ⅰ received intubation dose of cisatracurium 0.15 mg·kg-1.The partients in group Ⅱ received rocuronium 0.09 mg·kg-1.The patients in group Ⅲ received the patients cisatracurium 0.015 mg·kg-1 as a priming dose,and after a 3 min priming time,intubation doses of cisatracurium 0.135 mg·kg-1 were given to the patients again.The patients in group Ⅳ received intubation dose of rocuronium 0.9 mg·kg-1.Anesthesia for 4 groups were maintained with cisatracurium 0.03 mg·kg-1.Neuromuscular blockade was monitored using acceleromyography.The time for the first twitch height percentage(T1/T0%) reached zero(the onset of cisatracurium) and the evoked EMG to spontaneously return to 25%,75% and the recovery index were obtained.RESULTS GroupⅡand Group Ⅲ significantly accelerated the onset of cisatracurium(P0.05),but the onset was delayed in group Ⅳ.Females in Group Ⅳ had faster onset of paralysis than males(P0.05),and old patients in Group Ⅳ had a longer duration of paralysis than young ones(P0.05).The clinical duration of the first and last maintenance doses(cisatracurium) was prolonged after rocuronium was administered(Group Ⅳ)(P0.05).Howerer,there were no statistical differences in the recovery index(P0.05).CONCLUSION Rocuronium and cisatracurium can significantly accelerate the onset of cisatracurium,and the clinical duration and maintenance doses of cisatracurium was prolonged following rocuronium.