Effects of dexmedetomidine on succinylcholine-induced myalgia in the early postoperative period

To determine the effects of dexmedetomidine on the incidence of fasciculation and myalgia, and to evaluate changes in creatine kinase levels due to succinylcholine administration.

Sixty patients undergoing direct laryngoscopy were enrolled in this study carried out in the Department of Anesthesiology and Reanimation, Hacettepe University, Ankara, Turkey between January and March 2010. Patients were allocated blindly to 3 anesthesiologists. In the dexmedetomidine group (group D) (n=30), dexmedetomidine 1ug/kg was administered intravenously over 10 minutes before the intubation. In the control group (group C) (n=30), the same volume of normal saline was administered. Laryngoscopy was performed one minute after administration of succinylcholine. Dexmedetomidine infusion was continued until the end of surgery. Fasciculation and myalgia at the postoperative thirtieth minute, and creatine kinase levels before the induction of anesthesia and at the postoperative 24th hour, and adequacy of relaxation for intubation were recorded.

The severity and incidence of fasciculation were better in group D than group C (p=0.025). Intubating conditions were better in the dexmedetomidine group (p=0.011). At the thirtieth minute, the incidence and severity of myalgia were significantly higher in group C (p=0.014). Postoperative creatine kinase levels increased significantly compared with their base-line levels in both groups (p=0.022 in group D and p=0.017 in group C). Creatine kinase level elevation was higher in group C (p=0.03).

Dexmedetomidine infusion before and after succinylcholine administration may be useful in diminishing the incidence of succinylcholine-induced myalgia in the early postoperative period. Routine use of dexmedetomidine cannot be recommended, but further research is needed with a larger number of patients.