What is the first step when using an Automated External Defibrillator (AED)?

The first step when using an Automated External Defibrillator (AED) is to turn on the AED and follow the audio/visual prompts. Turning on the AED immediately initiates its operational functions and provides crucial instructions for the responder to follow. These prompts guide the user through the next appropriate actions, ensuring that the device is used correctly and efficiently. This step is vital because it prepares the device to analyze the heart rhythm and helps the responder to understand the necessary steps to take, which could potentially save a life.

The other actions, such as checking the patient's pulse or attaching the electrodes, are important but should follow the activation of the AED. Calling for emergency assistance is also critical, but this can often be done simultaneously or shortly before turning on the AED, depending on the situational context. However, the priority is to turn on the AED first to ensure it is ready to analyze the patient's condition and provide direction.