High-energy versus low-energy defibrillation: experience in patients (excluding those in the intensive care unit) at Mayo Clinic-affiliated hospitals.

/he purpose of this study was to determine whether electric shocks of low (200 to 240 J), intermediate (300 to 320 J), or high (400 to 440 J) delivered energy were most successful in defibrillating hospitalized patients (excluding those in intensive care units) in whom resuscitation was attempted by a code emergency team. From January 1980 through December 1982, 101 cases of ventricular fibrillation in 100 patients were treated by Mayo Clinic code emergency teams. Many of the patients in this trial had secondary or agonal ventricular Defibrillation. Most patients (64%) were defibrillated by one to eight shocks. For the first shock, intermediate and high energy seemed to be more effective than low energy. Patient weight, time of delivery of shock 1 after onset of the code emergency, blood pH, acute and chronic medical diagnoses, and pharmacotherapy before the onset of ventricular fibrillation were not clearly related to the response to shock 1. Nine of 16 patients who did not initially respond to shocks of low or intermediate energy were defibrillated when higher energy was subsequently used. Only 14 patients ultimately survived and were dismissed from the hospital. These results suggest that in this patient population, high levels of delivered energy are preferable to low energy for the first shocks administered; we recommend that 400 J of delivered energy be used initially. The 360-J maximal energy dose available in most currently manufactured defibrillators should be sufficiently close to this recommendation to justify use of that dose with the initial shock.(ABSTRACT TRUNCATED AT 250 WORDS)