A comparison of the onset and clinical duration of high doses of cisatracurium and rocuronium

Study Objective: To determine the onset and clinical duration of cisatracur ium and rocuronium in equipotent doses in balanced opioid/isoflurane anesth esia Design: Randomized, controlled study. Setting: University hospital. Patients: 40 healthy patients scheduled for elective surgery. Interventions: Patients underwent anesthesia induction with thiopental or p ropofol with a cisatracurium intubating dose of either 0.15 or 0.2 mg/kg or a rocuronium dose of either 0.9 or 1.2 mg/kg. These doses correspond to th ree and four times the ED95 dose. Measurements and Main Results: The onset time and time to 25% recovery of b aseline first twitch in a train-of-four were determined using an accelerome tric sensor. Rocuronium had a faster onset time that cisatracurium at equip otent doses (3 X ED95: 134 vs. 220 sec respectively, and at 4 X ED95: 95 vs . 162 sec). Recovery tended to be faster, but not statistically different f or cisatracurium compared to rocuronium. Conclusions: With equipotent intubating doses of rocuronium and cisatracuri um, rocuronium produces a more rapid onset of muscle relaxation. The data s uggest a tendency toward more rapid clinical recovery of cisatracurium comp ared to equipotent doses of rocuronium, although these differences were not statistically significant. (C) 1999 by Elsevier Science Inc.