Prevention of etomidate-related myoclonus in anesthetic induction by pretreatment with magnesium

BACKGROUND Etomidate frequently leads to myoclonic jerks during anesthetic induction. This study aimed to detect if pretreatment with magnesium decreases myoclonus incidence. METHODS A hundred ASA (the American Society of Anesthesiologists) I-II patients were included and randomized into 2 groups. Three minutes before etomidate induction of anesthesia (by 0.3 mg/kg intravenous etomidate), Group M received 2.48 mmol (60 mg) intravenous magnesium sulphate and Group P received equal volume of intravenous saline. Myoclonus was evaluated as "present/absent". RESULTS The rate of myoclonus was significantly lower in Group M than in Group P (p < 0.01). Hemodynamic parameters revealed no significant difference between the two groups. CONCLUSIONS Low dose magnesium pretreatment before etomidate induction of anesthesia significantly reduces unwanted myoclonic jerks and also protects the hemodynamic stability.