Dexmedetomidine versus Lignocaine in the Prevention of Etomidate-induced Myoclonus-A Randomised Double-blinded Study

Introduction: Etomidate is a preferred induction agent owing to its stable haemodynamic profile, minimal respiratory side-effects, minimal histamine release, cerebral protection and its property of rapid onset and short duration. However, myoclonus has been reported as one of its side-effects which poses great concern. Amongst the various drugs used to attenuate it, the role of intravenous (i.v.) Dexmeditomidine and Lignocaine have been reported in literature to be of great success. Aim: To compare the efficacy of Dexmedetomidine and Lignocaine in preventing Etomidate-induced Myoclonus. Materials and Methods: The randomised, double blinded study included 104 adult consented patients, of either sex, American Society of Anaesthesiology (ASA) I and II, aged 18-65 years, undergoing routine surgery under general anaesthesia. They were randomly allocated into two groups of 52 patients each viz., Group I receiving 0.5 mu g/kg of injection (inj.) Dexmedetomidine i.v. and Group II 1 mg/kg of inj. Lignocaine diluted in 10 mL normal saline i.v. The incidence and severity of myoclonus were assessed and recorded within 90 seconds after etomidate injection using a four point severity scale. The collected data were entered in Statistical Package for Social Sciences (SPSS) version 21.0. Results: Total 104 subjects with the demographic parameters such as age, sex, ASA and weight comparable between the two groups were analysed. Group I recorded lesser number of patients (17, 32.7%) to myoclonus as compared with Group II (21, 40.4%), (p-value=0.41). Maximum patients in Group I developed grade I myoclonus while in Group II, it was grade 2. No patients in Group I developed grade 3 myoclonus as against 5 patients in Group II (p-value=0.03). Conclusion: Dexmedetomidine and Lignocaine were equally effective in the prevention of Etomidate-induced myoclonus but dexmeditomedine was better because of lesser incidence of severe grade myoclonus.