Background: The purpose of this study was to assess the effect of rocuronium pretreatment on the succinylcholine-induced fasciculations, myalgia and biochemical changes, and to compare it with vecuronium pretreatment.
Methods: We have studied 60 female patients undergoing minor elective surgery, in a prospective double blinded method. Three groups of 20 patients each was pretreated with either saline (control group), rocuronium 0.05 mg/kg (rocuronium group) or vecuronium 0.007 mg/kg (vecuronium group). Three min after the pretreatment, 1.5 mg/kg succinylcholine was injected. Single twitch responses to electrical stimulation were measured. Serum potassium and creatine kinase were respectively measured 5 min after succinylcholine and 24 h after operation. Fasciculations and myalgia on postoperative day 1 and day 2 were evaluated.
Results: The incidence of fasciculations was lowest in the rocuronium group, followed by the vecuronium group, and was highest in the control group. The incidence of myalgia on postoperative day 1 was lower in the rocuronium and vecuronium groups than the control group. The increase of serum creatine kinase was similar among the three groups, but there was no increase in serum potassium concentration in any group. No differences of the single twitch responses to electrical stimulation were found between the rocuronium and vecuronium groups.
Conclusions: Rocuronium pretreatment was more effective in reducing fasciculations than was vecuronium pretreatment, but both were equally effective in preventing myalgia on postoperative day 1. This difference may reflect the differential activities of rocuronium and vecuronium at the neuromuscular junction. The increase of creatine kinase was not attenuated by any regimen.