Energy requirement for early defibrillation

The appropriate energy requirement for defibrillation of out-of-hospital ventricular fibrillation has been a matter of discussion. We analysed the effects of 360 J, 200 J or a combination of 200 and 360 J DC shocks given by ordinary manual defibrillators or semiautomatic defibrillators. 120 of 127 ventricular fibrillation episodes were converted by three or less 360 J DC shocks delivered by a manual defibrillator. All 28 ventricular fibrillation episodes were converted by an average of 1.9 DC shocks when 360 J were delivered by a semiautomatic defibrillator. 139 of 152 ventricular fibrillation episodes were converted by three or fewer 200 J DC shocks and 52 of 53 by 2 x 200 J followed, if needed, by 1 x 360 J DC shock delivered by the same semiautomatic defibrillator. Three or fewer 360 J DC shocks seems completely adequate for conversion of most episodes of out-of-hospital ventricular fibrillation. There is no difference in the result of defibrillation by manual and semiautomatic defibrillators.