Median effective dose of rocuronium for the prevention of succinylcholine-induced fasciculation: an age-stratified study.

backgroundSuccinylcholine, a commonly used depolarizing neuromuscular blocking relaxant, may produce fasciculation and postoperative myalgia as adverse effects. Although rocuronium pretreatment may attenuate this adverse effect, the median effective dose remains undetermined, as does the influence of age on it. This study was carried out to explore the median effective dose of pretreated rocuronium in inhibiting succinylcholine-induced fasciculation and to investigate the influence of age on the median effective dose of rocuronium.

methodsSeventy-two adult participants undergoing elective general anesthesia were stratified according to age: Group R1 (18-44 years), Group R2 (45-59 years), and Group R3 (60-80 years). The initial dose of prophylactic rocuronium was set at 0.04 mg/kg. Midazolam 0.05 mg/kg, sufentanil 0.4 µg/kg, propofol 1.5-2.5 mg/kg, and succinylcholine 2 mg/kg were then sequentially administered 1.5 min later, then fasciculation was assessed. The rocuronium doses were adjusted according to the assessment of fasciculation using Dixon sequential method, with a ratio of 1.1 between adjacent doses. The occurrence and grades of fasciculation, adverse reactions of rocuronium, and endotracheal intubating condition were recorded. The median effective dose and 95% confidence interval of rocuronium were calculated.

resultsThe median effective dose and 95% confidence interval of prophylactic rocuronium for the prevention of succinylcholine-induced fasciculation were 0.027 mg/kg (95% confidence interval: 0.026-0.028 mg/kg), 0.026 mg/kg (95% confidence interval: 0.024-0.029 mg/kg), and 0.026 mg/kg (95% confidence interval: 0.025-0.027 mg/kg) in Group R1, Group R2, and Group R3, respectively. No significant differences exist in the median effective dose among the three groups (P > 0.05). Only one patient experienced temporary diplopia in Group R2. No significant differences were found in fasciculation grades or endotracheal intubation conditions among the groups.

conclusionProphylactic intravenous rocuronium effectively prevents succinylcholine-induced fasciculation, with the median effective dose remaining consistent across age groups (18-44, 45-59, and 60-80 years).

trial registrationThe study was registered at ClinicalTrials.gov (Registration number: NCT05909696) on June 10, 2023. URL: https://clinicaltrials.gov/ .