Low-Dose Intravenous Midazolam Reduces Etomidate-Induced Myoclonus: A Prospective, Randomized Study in Patients Undergoing Elective Cardioversion

Abstract

IV midazolam 0.015 mg/kg administered 90 s before induction of anesthesia with etomidate is effective in reducing myoclonic movements and does not prolong recovery in unpremedicated patients after short procedures.

Lidocaine pretreatment reduces the frequency and severity of myoclonus induced by etomidate

“…Although the mechanism of the myoclonus is not clear, benzodiazepines, opioids, and rocuronium have been used as pretreatments to reduce etomidate-induced myoclonus [6][7][8][9][10]. However, no published data are yet available about the effects of lidocaine on myoclonus after injection of etomidate.…”

“…Also, in recent research Choi et al [16] showed that pretreatment with rocuronium significantly reduced the frequency of myoclonus due to etomidate by blocking transmission at the neuromuscular junction. But clinically distressing side effects are frequently observed, for example sedation, apnea, chest muscle rigidity, cardiovascular depression for opioids, delayed recovery for benzodiazepines, and airway obstruction, regurgitation, and aspiration for muscle relaxants [10,13,16]. An ideal pretreatment drug for preventing myoclonic movements should be shortacting, not have significant effects on respiration and hemodynamics, and not prolong recovery from anesthesia [10].…”

“…But clinically distressing side effects are frequently observed, for example sedation, apnea, chest muscle rigidity, cardiovascular depression for opioids, delayed recovery for benzodiazepines, and airway obstruction, regurgitation, and aspiration for muscle relaxants [10,13,16]. An ideal pretreatment drug for preventing myoclonic movements should be shortacting, not have significant effects on respiration and hemodynamics, and not prolong recovery from anesthesia [10]. In this respect, pretreatment of myoclonus with lidocaine is capable of reducing the occurrence of myoclonic movements and deserves further study.…”

Effectiveness of Midazolam in the Prevention of Etomidate Induced Myoclonus

“…They concluded that pretreatment with midazolam is effective in reducing the incidence of myoclonic movements while preserving the advantage of etomidate; that is, cardiovascular stability and short duration of action [3]. Huter et al investigated the effects of low dose intravenous midazolam pretreatment 0.015 mg/kg on the incidence and severity of myoclonus during induction of anaesthesia with etomidate for elective cardioversion in un-premedicated patients and it was found that 10% of patients in midazolam group had myoclonic movements as compared to 50% receiving placebo [10].…”

Pretreatment with butorphanol reduces myoclonus after etomidate

“…Pain on injection has been abolished by the new fat emulsion of etomidate, but the new solvent has not reduced the incidence of myoclonus [2]. Myoclonus is a common problem during induction of anesthesia with etomidate; up to 80% of non-premedicated patients develop myoclonic movements, [3] which may be a problem in the non-fasting patient because of the risk of hypoventilation as well as theoretically regurgitation and aspiration [4,5]. In patients with an open globe injury, myoclonus after etomidate raises the risk of prolapse of vitreous material as a result of high intraocular pressure [6].…”