What is an AED? This medical device can save lives after cardiac arrest.

What is an AED? Here's why it can save lives. (Photo: Getty Images)
What is an AED? Here's why it can save lives. (Photo: Getty Images)

About 90% of the 350,000 cardiac arrests that happen outside a hospital each year are fatal. However, a simple medical device, an automated external defibrillator (AED), can save lives.

According to Dr. Janice Tijssen, director of pediatric critical care medicine at London Health Sciences Centre and Emergency Cardiovascular Care committee volunteer at the American Heart Association, AEDs are “an important part of responding to a cardiac arrest,” along with providing CPR (cardiopulmonary resuscitation), and that, ideally, they should always be used together.

“A person’s chance of surviving drops by 7% to 10% every minute a normal heartbeat isn’t restored. So, immediate CPR and AED use could double or triple the person’s chance of survival. CPR combined with using an AED provides the best chance of saving a life,” she says.

What is an automated external defibrillator (AED)?

An AED is a lightweight, portable device that delivers an electric shock through the chest to the heart when it detects an abnormal rhythm. Its purpose is to change the rhythm back to normal, according to Tijssen.

“AEDs help people who have a sudden cardiac arrest, which occurs when the heart suddenly stops beating regularly,” she explains. “This happens when the heart’s natural electrical system doesn’t work correctly. If not treated within minutes, cardiac arrest quickly leads to death.”

AEDs are extremely useful as they are “safe, accurate and easy to use,” so it makes sense to have the device in locations where people gather.

When should you use an AED?

According to Q Rothing, a former EMT (emergency medical technician) and the owner of Montana-based first-aid training company Jolt CPR, an AED should be used when a person “doesn’t respond to being spoken to or to physical touch,” and when they are not breathing normally — something indicated when the person gasps during what's known as agonal breathing.

“If that’s the case, CPR should be initiated and an AED should be initiated as soon as it is available,” he tells Yahoo Life.

An AED, if readily available when a person goes into cardiac arrest, is the best first line of defense, followed by CPR, Rothing explains. If the device is not ready for use, then it’s best to start with CPR until it is.

“It’s critical to know what to do in the moments that matter,” says Dr. Nici Singletary, co-chair of the American Red Cross Scientific Advisory Council and professor of emergency medicine at the University of Virginia. “If you see someone collapse and you don’t know CPR, call or have someone else call 911, start hands-only CPR [in which you push hard and fast on the center of the chest] and use an AED if one is available.”

How do you use an AED?

AEDs are especially useful because one can use them without training — though some training doesn't hurt in order to feel even more confident in an emergency situation.

These are the steps to follow when using the AED, according to Tijssen:

  • Turn on the AED and follow the voice prompts.

  • Remove all clothing covering the chest. If necessary, wipe the chest dry.

  • Peel away the backing from the pads and attach the pads to the person’s bare chest, following the illustration on the pads.

  • Plug the pads’ connector into the AED, if necessary.

  • The AED will check to see if the person needs a shock and will automatically give one or tell you when to give one. While the AED is analyzing, make sure no one is touching the person.

  • Resume CPR if no shock is needed. If a shock is needed, make sure no one is touching the person and press the shock button, then immediately resume CPR.

  • Continue CPR until emergency medical personnel arrive.

While some people may be worried that they are using an AED wrong and therefore causing more harm, Rothing ensures it isn’t possible.

“AEDs are designed in a way so that if they are used incorrectly, they do not do any harm to the patient,” he says. “While some AED cabinets will say ‘Trained Professionals Only,’ you cannot hurt somebody, nor will you be held liable in any way for using an AED without training.”

Where are AEDs typically located?

Installed AEDs are marked with clear signage and feature a red heart with a white lightning bolt symbol.

“Apart from the hospitals, ambulances and law enforcement vehicles, firefighters and first responders carry an AED,” says Dr. Sachin Agarwal, associate professor of neurology and director of the NeuroCardiac Comprehensive Care Clinic at Columbia University Irving Medical Center. “In public spaces, AEDs are found in restaurants, sports fields and arenas; airports, airplanes, malls and other public buildings with high foot traffic; hotels, schools, public pools, health and fitness centers, commuter rails and libraries. They should be in every public or private place where large numbers of people gather.”

AEDs are typically found near the entrances to buildings, or near the bathrooms, and may also be found near elevators, in cafeterias and in main reception areas or hallways. Employees will know where an AED is located.

Should you have an AED at home?

While it’s not very common for people to have an AED at home, Rothing says he has found more people are seeking them out.

“A lot of people are looking at carrying them in their cars, so that they have them more often than not,” he explains. “You can have them at home, at work, camping. The prices of AEDs are slowly coming down and becoming more affordable to the general public, so we are seeing more of that.”