A comparison of fentanyl and dexamethasone pretreatment for prevention of etomidate induced myoclonus, a randomized double blind placebo controlled study

Background and Aims: Etomidate is used for induction of anaesthesia in haemodynamically unstable patients but its use is associated with undesirable side effects like myoclonus, incidence of which is 50- 80%. This prospective, randomized, placebo controlled study is to compare the effect of dexamethasone and fentanyl for prevention of etomidate induced myoclonus. Materials and Methods: Ninety adult patients were randomly assigned into three groups to receive Dexamethasone (group D), Fentanyl (group F) and placebo (group P) five min before injection etomidate 0.3mg/kg IV. The patients were assessed for myoclonus using a four point intensity scoring system over a period of 5 min. ANOVA and chi square test were used for statistical analysis and P as statistically significant. Results: The incidence of myoclonus was significantly reduced in groups D and F compared with group P (p value 0.001).The incidence of pain associated with Etomidate induced myoclonus also was significantly reduced in groups D and F compared to group P (p value 0.001). Conclusion: Dexamethasone significantly reduces the incidence of myoclonus as compared to placebo. It also significantly reduces the pain associated with Etomidate injection. However its efficacy to reduce pain and myoclonus as compared to Fentanyl is much less. Keywords: Etomidate, Myoclonus, Dexamethasone.