What is the correct energy setting for the first defibrillation in a biphasic defibrillator for a patient in ventricular fibrillation?

The first defibrillation attempt in a patient experiencing ventricular fibrillation with a biphasic defibrillator is typically set at 150 joules. This choice aligns with current guidelines that recommend starting with lower energy levels in biphasic devices, as they are effective at terminating ventricular fibrillation while reducing the risk of myocardial damage and improving patient outcomes. Biphasic defibrillators deliver energy in two directions, which contributes to their efficacy at these settings.

By beginning with 150 joules, healthcare providers can strike an effective balance between delivering sufficient energy to restore normal heart rhythm and minimizing potential complications associated with higher energy levels. Subsequent shocks, if necessary, may be increased, but the initial dose is crucial for providing an optimal chance of success.