Which of the following best characterizes proper use of an AED?

The best characterization of proper use of an AED is that it analyzes the heart rhythm and advises shock delivery. This is a key function of the AED, as the device is designed to assess an unresponsive patient's heart rhythm and determine if a shock is necessary to restore a normal heartbeat. When used appropriately, the AED provides clear instructions to the rescuer, indicating when to deliver a shock and when to perform CPR.

For instance, understanding that the AED automatically evaluates the heart's electrical activity allows bystanders to quickly follow the device's prompts, which can significantly improve the chances of survival for someone experiencing a cardiac arrest. This functionality supports the timely and effective use of the AED as part of the chain of survival in emergencies.

In contrast, while CPR is crucial, the AED does not require several minutes of CPR before its use; it is meant to be used as soon as possible. The pads for the AED may be sized and placed differently depending on the patient's age and size, meaning that using them regardless of the patient's age could potentially lead to ineffective treatment. While the AED is incredibly important, it is one part of the broader strategy for addressing cardiac arrest, rather than being the single most important tool.