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.