A COMPARISON OF PROPOFOL AND ETOMIDATE FOR CARDIOVERSION

Bolus doses of propofol in patients for cardioversion often produce hy potension and apnea. Etomidate provides cardiovascular stability in th ese patients, but myoclonus may interfere with electrocardiographic in terpretation. This study was designed to demonstrate whether propofol, when given as a low-dose infusion, can attain etomidate's hemodynamic stability without its attendant side, effects. Forty consenting patie nts were randomly assigned to receive either propofol infusion (50 mg/ min) for induction of anesthesia followed by a maintenance infusion (1 00 mug-kg-1.min-1) or etomidate (8 mg/min and 20 mug.kg-1.min-1). Calc ulation of loading infusion rates for propofol and etomidate resulted in averages of 0.64 mg-kg-1.min-1 (range, 0.39-1.04) and 0.09 mg-kg-1. min-1 (range, 0.05-0.14), respectively. Induction times (2.2 min) and the times from terminating drug administration to awake states (4.5 mi n) were similar for each group. Etomidate produced myoclonus in 45% of the patients; otherwise side effects were minimal, with no significan t differences between groups. The means of systolic blood pressures in the etomidate group rose a maximum of 15.3 +/- 7.9% (95% confidence), while a modest decrease of 7.2 +/- 7.3% occurred with propofol. Admin istration of propofol by infusion for cardioversion retains all its be neficial qualities while attenuating its hypotensive effects, making i t a suitable choice for these patients with cardiac arrhythmias.