A comparison of epinephrine and methoxamine for resuscitation from electromechanical dissociation in human beings

Abstract

Electromechanical dissociation (EMD) is an organized electrical depolarization of the heart without synchronous myocardial fiber shortening and, therefore, without cardiac output. Patients in EMD have a poor prognosis for resuscitation and long-term survival. The beneficial effect in resuscitation of epinephrine, the adrenergic agent currently recommended, has been shown to depend on stimulation of alpha-adrenergic vasoconstriction. The beta-adrenergic inotropic and chronotropic effects of epinephrine are theoretically detrimental by increasing myocardial oxygen consumption and subendocardial ischemia. The purpose of our study was to determine whether the pure alpha agonist methoxamine was superior to epinephrine in human beings in EMD as determined by survival at one hour. These two agents were compared in a prospective, randomized, and double-blinded study involving 80 patients with EMD of various causes seen in the emergency department and internal medicine inpatient service. The advanced cardiac life support (ACLS) algorithm (current at the time of our study) for resuscitation from EMD was used, with the blinded study drug (epinephrine 1 mg or methoxamine 10 mg) administered where the algorithm calls for epinephrine. Calcium and isoproterenol also were used in the majority of cases according to ACLS standards but never prior to the use of methoxamine or epinephrine. Survival data are summarized as: survival less than one hour, 22 patients receiving methoxamine, 22 receiving epinephrine; one to six hours, 15 patients receiving methoxamine, 13 patients receiving epinephrine; six to 12 hours, one patient receiving epinephrine; more than 24 hours but not surviving to discharge, three patients receiving methoxamine, two patients receiving epinephrine; and survival to discharge, one patient receiving epinephrine.(ABSTRACT TRUNCATED AT 250 WORDS)