To compare the efficacy of three techniques in reducing etomidate-induced myoclonus - A randomised controlled trial.

Background and aims: Etomidate is the preferred induction agent in haemodynamically unstable patients. Preventing etomidate-induced myoclonus (EIM) is important. The objective of this study was to compare the efficacy of three techniques of etomidate administration in preventing EIM.

Methods: This randomised, controlled study included 296 patients. General anaesthesia (GA) was induced with etomidate as per the randomly allocated groups: control (C), priming (P), slow (S), and priming with slow injection (T). The incidence, time of onset, and grade of myoclonus were noted. The grade of pain on injection and the effect on various haemodynamic parameters were noted. The Kruskal-Wallis, Fisher's exact, and Chi-square tests were used for statistical analysis. P < 0.05 was considered to be statistically significant.

Results: The study shows that the incidence of myoclonus was highest amongst Group C (73.0%), followed by Group P (52.7%), Group S (48.6%), and Group T (37.8%) (P = 0.001). Priming with a slow technique was most effective in preventing EIM and lowering the intensity of myoclonus. The incidence of grade 3 myoclonus was 5 (6.76%) in Group T when compared to 39 (52.7%) in Group C (mean difference [MD] =36.96, 95% CI: 7.45, 55.94; P = 0.0001).

Conclusion: We observed that the priming and slow injection techniques were similar in reducing the incidence of EIM. However, the combination of priming and slow technique was the most effective.