Automated External Defibrillators

An AED is about the size of a laptop computer and is used to deliver a specific electric shock to the heart to restore the heart’s rhythm.  Defibrillators have been used for years in hospitals and by EMS to deliver life-saving shocks.  

In the late 1980’s technology was developed that would allow the machine (rather than the rescuer) to decide whether or not a shock was needed.  These new machines were initially used by police officers and basic EMS responders (who were not previously trained in defibrillation).  Their success rates were equal to, or better than, more highly trained medical personnel.  With this information (and more refinements), AEDs began to appear in public venues in the late 1990’s and in many cases were successfully used by people without previous medical training.  

The critical element of AED success is time.  Data collected from previous (and ongoing) public AED placements suggest that victims lose about 10 percent of their chance to be successfully resuscitated or revived with each passing minute.  In other words, using an AED within three minutes of collapse is more likely to revive a victim than to use it after eight minutes.  Some public-access sites report survival from sudden cardiac arrest to be greater than 70 percent!

It’s important to note that heart fibrillation is the most common cause of sudden cardiac arrest but not the only cause.  Therefore, on some emergencies an AED will choose not to shock the victim.  You cannot override it—in other words, for those few victims who don’t need a shock, you can’t accidentally deliver one.

Learn how easy it is to operate an AED