Evaluation Background: Automated External Defibrillators (AEDs)

Here's background for our Evaluations of automated external defibrillators (AEDs), outlining the key considerations for making wise purchasing decisions. Learn how the technology is used, which specs are important, and what factors we test for. Also review our latest product ratings and ECRI's data describing hospitals' interest in each vendor.

AEDs are used to analyze a patient's ECG and determine whether a defibrillation shock is warranted. If a shock is appropriate, the AED will either deliver the shock automatically (if the device is fully automated) or prompt the user to press a button to deliver the shock (if semiautomated). If a defibrillation shock is not appropriate, the AED will advise against a shock, and will guide the user to perform cardiopulmonary resuscitation (CPR) until medical assistance arrives.

Although there is overlap between the capabilities of AEDs and manual monitor/defibrillators, devices in the AED category are designed primarily:

1. For use by individuals without advanced cardiac life support (ACLS) training. Users typically have CPR training or basic life support (BLS) training, but are not certified to analyze a cardiac rhythm and recommend a shock. Therefore, the default mode of operation for an AED is to provide automatic guidance on resuscitation steps, including automatic ECG analysis.

2. To deliver a lifesaving defibrillation shock, with no additional therapeutic or monitoring capabilities. AEDs are not able to provide cardioversion, pacing, or physiologic monitoring (e.g., noninvasive blood pressure monitoring).

3. To be very easy to use. They provide audio instructions to device operators for key steps such as electrode application and CPR. They are also preprogrammed to require minimal input from the operator.

Another key defining characteristic of these devices is their low cost. AEDs are intended to be broadly distributed in public spaces, in order to reduce the time until first shock; therefore, the capital purchase price tends to be relatively low (approximately $1,000-$3,000). In comparison, their more advanced monitor/defibrillator counterparts (which are primarily intended for paramedics, emergency physicians, and cardiology/electrophysiology departments) cost approximately $16,000-$30,000. However, consumables (such as defibrillation electrodes and replacement batteries) may add considerably to the cost if the AED is used frequently.

The first clinical studies on AEDs were published in the 1980s. In 1995, the International Liaison Committee on Resuscitation (ILCOR) and its member organizations (including the American Heart Association AHA) emphasized the importance of early defibrillation and began to recommend the use of AEDs. Since then, AEDs have become common, being used by healthcare facilities, medical first responders (e.g., emergency medical technicians EMTs), nonmedical first responders (e.g., police and firefighters), and nonmedical facilities (e.g., schools, workplaces, athletic facilities, shopping malls, places of worship).

Some newer AEDs have incorporated more advanced features, such as the...