Transthoracic Incremental Monophasic Versus Biphasic by Emergency Responders (TIMBER)

The trial is designed to determine whether two fully-FDA-approved, commercially available transthoracic defibrillation shock waveforms at comparable energies result in improved patient outcome following out-of-hospital cardiac arrest due to ventricular fibrillation. Eligible subjects include all adults with nontraumatic out-of-hospital cardiac arrest due to ventricular fibrillation. Subjects in cardiac arrest will be randomly allocated to receive one of two types of defibrillation shocks (monophasic or biphasic waveform) during their resuscitation, which will in addition include all other standard treatments. The primary endpoint is admission alive to hospital. Secondary endpoints include rhythm after defibrillation shock, return of spontaneous circulation, and hospital discharge rates.