Magnesium sulfate in the treatment of refractory ventricular fibrillation in the prehospital setting

Objective: To determine if magnesium sulfate (MgSO4) improves outcome in cardiac arrest patients initially in ventricular fibrillation (VF). Methods: Randomized, prospective, double blind, placebo-controlled, multicenter prehospital trial using 2 g of MgSO4. Eligible patients were non-traumatic cardiac arrest patients ( greater than or equal to 18 years of age) presenting in VF. The protocol included those patients refractory to three electroshocks. Epinephrine and either 2 g of MgSO4 or placebo (normal saline) were then administered. The primary outcome variable was return of spontaneous circulation (ROSC) in the field and a perfusing pulse on arrival at the ED. Secondary endpoints included admission to the hospital (ADMT) and hospital discharge (DISC). IRB approval was obtained at all participating centers. Results: Total 116 patients (58 MgSO4, 58 placebo) were enrolled during the period from 4/1992 to 10/96 with 109 available. There were no significant differences between the groups in baseline characteristics and times to cardio pulmonary resuscitation (CPR), advanced life support (ALS), and first defibrillation, except for time to study drug administration. There was no significant differences in ROSC (placebo, 18.5%, and MgSO4, 25.5%, P = 0.38), ADMT (placebo rate = 16.7%, MgSO4 = 16.4%, P = 1.0) or DISC (placebo rate = 3.7%, MgSO4 = 3.6%, P = 1.0). Conclusions: We failed to demonstrate that the administration of 2 g of MgSO4 to prehospital cardiac arrest patients presenting in VF improves short or long term survival. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.