Abstract 237: Comparative Efficacy of Biphasic Waveform Defibrillation Energies for In-Hospital Cardiac Arrest: Insights from the Get With The Guidelines--Resuscitation Registry

Abstract

Background: Biphasic waveforms have become the predominant choice for defibrillation of cardiac arrest due to pulseless ventricular tachycardia or ventricular fibrillation (VT/VF). However, little is known about the relative efficacy of different first shock energy levels for defibrillation of VT/VF. Methods: Within the Get With The Guidelines - Resuscitation multicenter observational registry, we identified adults who received biphasic waveform defibrillation for in-hospital cardiac arrest due to VT/VF between 2005 and 2012. Using hierarchical regression to adjust for patient arrest characteristics and comorbidities while accounting for clustered observations by hospital, we examined the risk-adjusted association between the energy level (100J, 120J, 150J, 200J, 300J, or 360J) of the first defibrillation attempt and patient outcomes. Our primary outcome was termination of VT/VF following the first shock, with secondary outcomes of return of spontaneous circulation (ROSC), 24 hour survival, and survival to discharge. Results: Among 12,417 adults suffering VT/VF arrest treated with biphasic defibrillation, the most common first shock energy was 200 J (55.5%) Compared with 200 J, defibrillation with 120 J was more likely to result in termination of VT/VF and 24 hour survival and 150J was associated with greater 24 hour survival and survival to discharge. In contrast, energies higher than 200 J showed no difference in termination of VT/VF, but were associated with lower survival (see Table). Conclusion: Among adults with in-hospital cardiac arrest due to VT/VF, defibrillation with 200 J is the most common energy used for initial defibrillation with a biphasic waveform. However, initial defibrillation with lower energy levels is associated with greater odds of VT/VF termination, 24 hour survival, and survival to discharge. Further study is needed to inform the optimal energy for initial defibrillation of cardiac arrest due to VT/VF.