The Effect of Succinylcholine dosage on the Rate and Postoperative Severity of Postoperative Muscular Fasciculation and Pain

A common side effect associated with succinylcoline is postoperative myalgia. The pathogenesis of this myalgia is still unclear; therefore there is no ideal method of decreasing the rate and severity of fasciculation and postoperative myalgia. The aim of this prospective and randomized study was to evaluate the influence of low-dose succinylcholine for tracheal intubation on the rate and severity of fasciculation and postoperative myalgia. In this study, 60 patients of ASA physical grading I or II were randomly entered into two groups of 30 patients each. One fasciculation was evaluated on the basis of Mingus and myalgia on the basis of Harvey Induction of anesthesia was performed with fentanyl/thiopentone, and then succinylcholine 1 mg/kg (control group) and 0.6 mg/kg (case group) were administered to patients for tracheal intubation. There was not fasciculation in 50% (15 patients) of study group and on the rest no severe fasciculation occurred. Furthermore, the severity of fasciculation in the study group was significantly lower than that of control group (p<0.0001). In 16 (53.3%) patients of study group and 4 (13.3%) of control group myalgia were not occurred. Severity of myalgia was also significantly lower in study group than the control group (p<0.0001). Acceptable intubating conditions in all patients of two groups. Decreasing the dose of succinylcholine (from 1 mg/kg to 0.6 mg/kg) both provides acceptable intubation conditions, and reduces the rate and intensity of succinylcholine induced fasciculation and postoperative myalgia.