Rocuronium prevents succinylcholine-induced fasciculations

The aim of this study was to assess the effect of rocuronium pretreatment at 3 and 1.5 min before succinylcholine administration on fasciculations, neuromuscular blockade and intubating conditions.

Sixty ASA I or II adults scheduled for elective surgery were anaesthetised with midazolam, fentanyl, propofol, N2O and isoflurane. They were randomised in a double blind manner into three groups: group ROC-3 min (n = 22) received 0.05 mg.kg-1 rocuronium, 3 min before 2 mg.kg-1 succinylcholine; group ROC-1.5 min (n = 20) received 0.05 mg.kg-1 rocuronium 1.5 min before 2 mg.kg-1 succinylcholine; and group NO ROC (n = 18) had no rocuronium before injection of 2 mg.kg-1 succinylcholine. Fasciculations and intubating conditions were evaluated by the same physician who was unaware of the randomisation. Neuromuscular block was measured at the adductor pollicis with an accelerometer.

The incidence of fasciculations was lower in the ROC-3 min (9%) and ROC-1.5 min (30%) groups than in the NO ROC group (83%; P < 0.001). The intensity of fasciculations was also less in both pretreatment groups. No statistical difference was noted between pretreatment at 3 and 1.5 min. Intubating conditions, onset time and duration of succinylcholine blockade were comparable in all three groups.

The incidence and severity of succinylcholine fasciculations can be reduced by giving 0.05 mg.kg-1 rocuronium either 1.5 min or 3 min before succinylcholine. The effects of 2 mg.kg-1 succinylcholine with rocuronium pretreatment, and 1 mg.kg-1 succinylcholine, without pretreatment, are similar with respect to intubating conditions, onset of paralysis and duration of blockade.