Comparison of the influence of low dose etomidate and propofol as priming dose on the incidence of etomidate induced myoclonus: a randomised, double-blind clinical trial

Abstract

Background: Though hemodynamically stable, etomidate is known for its myoclonus side effect following induction. The main aim of this study is an effective attempt to decrease the incidence of myoclonus with a priming agent.

Methods: A prospective, double-blind study was carried out on 50 adults posted for elective surgery. After premedication, priming was done with etomidate 0.03 mg.kg^-1 (Group E) and propofol 0.2 mg.kg^-1 (Group P), i.e., 1/10th of induction dose. After 60 seconds of priming, patients were induced with etomidate by titrating dose over 60 seconds until loss of verbal command and eyelash reflex. The grading of myoclonus, induction dosage, and hemodynamics for 10 minutes post induction were recorded.

Results: In the study, only 4 cases had myoclonus. Grade 1 myoclonus was encountered in three cases of etomidate group, while only one case in the propofol group had grade 2 myoclonus which was not statistically significant (p-value: 0.12). There was a significant reduction in the etomidate induction dosage in both groups.

Conclusion: Priming with etomidate and propofol is equally effective in reducing myoclonus with the added benefit of hemodynamic stability and reduction of an induction dose of etomidate (> 50%).

Keywords: Etomidate; Myoclonus; Priming; Propofol.

Figure 1

Flow chart of participants in the study.

Figure 2

Incidence of myoclonus occurrence in the two groups. E, Group etomidate; P, Group propofol (p = 0.12).

Figure 3

Heart rate changes in the two groups. Premed, 5 minutes following premedication; 1, 1 minute following induction; 2, 2 minutes following induction; 3, 3 minutes following induction; 5, 5 minutes following induction; 6, 6 minutes following induction; 7, 7 minutes following induction; 8, 8 minutes following induction; 9, 9 minutes following induction; 10, 10 minutes following induction.

Figure 4

Mean arterial pressure trends in the two groups. MAP, mean arterial pressure; premed, 5 minutes following premedication; 1, 1 minute following induction; 2, 2 minutes following induction; 3, 3 minutes following induction; 5, 5 minutes following induction; 6, 6 minutes following induction; 7, 7 minutes following induction; 8, 8 minutes following induction; 9, 9 minutes following induction; 10, 10 minutes following induction.