Most Cardiac Arrest Patients Far From AEDs

Automated external defibrillators present at few cardiac arrest sites

(RxWiki News) In recent years there has been a push to install automated external defibrillators (AEDs) to treat cardiac arrest at public locations. These life saving devices are much more accessible, but are still short on access.

A new study found that more than 75 percent of cardiac arrest patients still are stricken too far from one of the devices for the installed AEDs to be beneficial.

"Begin CPR following cardiac arrest - do not wait."

Raina Merchant, MD, MS, senior author and an assistant professor of emergency medicine at Penn Medicine, noted that AEDs are essential to save cardiac arrest victims. She said that despite having thousands of them out in the community, they are usually not readily available during cardiac arrests.

AEDs are not subject to the same U.S. Food and Drug Administration regulations as their implantable counterpart so it is not clear where all of the public AEDs are located or if they were installed in areas where crowds are most likely to frequent.

Dr. Merchant said that, without an AED, the minutes bystanders spend waiting for paramedics to arrive could mean the difference between life and death.

During the study investigators mapped the locations of 3,483 out-of-hospital cardiac arrests, and also the locations of 2,314 AEDs in Philadelphia County. They found that 30 percent of AEDs were located in schools or universities, while 22 percent were in office buildings and 4 percent were in residential buildings.

But they found that only 7 percent of cardiac arrests happened within 200 feet, or a two minute round trip walk, of an AED. About 10 percent occurred 400 feet, or a four minute walk, away, while 21 percent were within 600 feet, or a six minute walk.

The findings were significant because the chance of surviving cardiac arrest drops 10 percent for each minute that passes without defibrillation or cardiopulmonary resuscitation (CPR). Patients shocked more than six minutes after they suffer cardiac arrest have very low chances of survival.

Investigators suggest additional AEDs are needed in more strategic locations in the community.

They also stress that the public needs help locating and using the devices in case of an emergency. One such initiative was Penn Medicine's MyHeartMap Challenge, a recent contest that asked residents to help pinpoint AEDs in the community.

They found more than 1,500. That data will be used to create an app to help bystanders locate AEDs in an emergency, and also will be provided to 9-1-1 operators so they can direct those in search of the devices.

The study was recently presented at the annual meeting of the Society for Academic Emergency Medicine.

Review Date: 
May 14, 2012