What is the recommended energy level for the first shock when using a defibrillator?

The recommended energy level for the first shock when using a defibrillator is typically set at 150 joules. This recommendation is based on evidence that suggests delivering an initial shock at this energy level provides a balance between efficacy and safety for the patient.

Using 150 joules as the initial energy allows for a sufficient dose of electrical energy to effectively depolarize the myocardial cells, increasing the possibility of restoring a normal rhythm in cases of ventricular fibrillation or pulseless ventricular tachycardia. Higher energy levels are often reserved for subsequent shocks, as the initial shock aims to achieve successful defibrillation with a balance that minimizes potential damage to the heart. Starting with 150 joules helps prevent the risks associated with excessive energy delivery while still aiming for effective patient outcomes.

This practice is grounded in clinical guidelines and research that support using moderate energy levels for optimal results. Therefore, starting with 150J is a well-established protocol in resuscitation guidelines.