COMPARISON OF ROCURONIUM, SUCCINYLCHOLINE, AND VECURONIUM FOR RAPID-SEQUENCE INDUCTION OF ANESTHESIA IN ADULT PATIENTS

Background: Succinylcholine has been the agent of choice when clinical conditions require emergency airway protection during a rapid-sequenc e induction of anesthesia. Rocuronium, a new nondepolarizing muscle re laxant with a brief onset of action, but devoid of the adverse reactio ns associated with succinylcholine, may be an alternative to succinylc holine. To test this hypothesis, the authors compared rocuronium with succinylcholine and vecuronium for rapid-sequence induction of anesthe sia. Methods. Fifty patients, ASA 1-3, were randomly designated to rec eive one of three intravenous doses of rocuronium (0.6, 0.9, and 1.2 m g/kg), vecuronium (0.1 mg/kg), or succinylcholine (1.0 mg/kg). Patient s were premedicated with midazolam and fentanyl, and received 2-7 mg/k g thiopental for induction of anesthesia. Sixty seconds after receivin g a muscle relaxant, intubation of the trachea was attempted by a clin ician who was blinded to the muscle relaxant administered. Neuromuscul ar monitoring was established before administration of the muscle rela xant. The time from injection of muscle relaxant until complete ablati on of T1 (onset) and recovery of Tl to 25% (duration) were recorded. T racheal intubating conditions were evaluated, and the presence or abse nce of fasciculations was noted. Results: Onset times for patients rec eiving 0.9 mg/kg (75 +/-28 s) and 1.2 mg/kg rocuronium (55 +/- 14 s), and succinylcholine 50 +/- 17 s) were similar. Onset times for the gro ups given 0.6 mg/kg rocuronium (89 +/- 33 s) and vecuronium (144 +/- 3 9 s) were significantly longer. Clinical duration of action was longes t with 1.2 mg/kg rocuronium, similar with 0.6 and 0.9 mg/kg rocuronium , and vecuronium, and least with succinylcholine. Conclusions: There i s a dose-dependent decrease in onset time with rocuronium. The onset t imes for the two larger doses of rocuronium were similar to that for s uccinylcholine, but clinical duration of action with rocuronium was si gnificantly longer. The brief onset time achieved with rocuronium indi cates that administration of 0.9-1.2 mg/kg is an acceptable alternativ e to succinylcholine for rapid-sequence induction of anesthesia.