Optimal Priming Dose of Rocuronium for Prevention of Succinylcholine Induced Fasciculations

ABSTRACT

BACKGROUND: Subparalyzing dose of nondepolarizing muscle relaxants is often given prior to succinylcholine to reduce its adverse effects. At the same time, priming dose may worsen the intubating condition due to its antagonizing effect at neuromuscular junction. Although optimal priming dose of rocuronium is known to 0.03-0.04 mg/kg but higher priming dose may reduce interval from priming drug to succinylcholine. This study was designed to determine the maximal priming dose of rocuronium. METHODS: Sixty ASA I or II adult patients were randomized into three groups: group R1 received 0.06 mg/kg of rocuronium, group R2, 0.09 mg/kg and group Scc, normal saline. About 3 minutes after priming dose, thiopental 4 mg/kg, fentanyl 1microg/kg and succinylcholine 2 mg/kg were administered for anesthesia induction. The presence and severity of fasciculations and intubating conditions were evaluated with the incidence of side effects. RESULTS: In preventing fasciculations, group R1 and R2 were significantly better than group Scc, without significant difference between group R1 and R2. Intubation conditions were significantly worse in group R2 than in group Scc. CONCLUSIONS: The maximal priming dose of rocuronium to prevent fasciculations and optimizing intubating condition was 0.06 mg/kg.