AED Education

The following is for informational purposes only. For training and advanced education, please visit the American Heart Association webpage, or you may contact us for more information. If you are experiencing an emergency, please call 9-1-1 immediately.


An automated external defibrillator (AED) is a device used to help revive ​​people who are experiencing cardiac arrest (when the heart is not beating), which is best used in combination with CPR. It is a portable electronic device that can analyze a person's heart and then can automatically deliver an electric shock to help correct or restart the heart rhythm.

AED's are designed to be easy to use by anyone of any age, although a short training class should be taken to help identify patient symptoms and indications. Modern AED's have speakers and will talk the rescuer through the steps to use the AED, even if the rescuer may not have done AED training recently. Children can learn to operate an AED as well.

What Happens During Cardiac Arrest

When someone's heart stops beating, the blood stops circulating through the body. As a result, oxygen is not delivered to their vital organs and the cells begin to die. The brain will start to develop damage until the blood flow is restarted, and this damage is more likely to be permanent the longer it takes.

CPR (cardio-pulmonary resuscitation) is an extremely useful rescue technique that works by compressing the person's chest in order to squeeze the heart and cause some blood to flow. This helps to provide some of the much-needed oxygen to the brain and other organs. However, in many situations, CPR by itself is unlikely to restart the person's heart (though not impossible). A primary benefit from CPR is that it helps to delay the permanent brain damage, giving more time for a rescuer to arrive with an AED, or a medic to arrive.

Benefits of an AED

An AED is a portable electronic device that comes with sticky pads that are placed on the patient's chest, connected by wires to the main unit. The AED is able to detect electrical signals from the patient's heart, analyze them, and then provide instructions for the rescuers. It is also capable of automatically delivering an electrical shock to restart the heart, if appropriate.

In this way, an AED is often able to restore the heartbeat, while CPR by itself can only provide a temporary delay. This is incredibly beneficial for the chances of recovery.

Statistics: If someone experiences a cardiac arrest (while not in a hospital), their chances of survival are:

  • ~​10% survive overall
  • ~30% survive if they are given CPR by a bystander
  • ~90% survive if an AED is nearby and is used within 60 seconds

Every additional minute that goes by without an AED results in 10% less survival. This shows that having an AED readily accessible is the most important factor in someone's survival of a cardiac arrest. In the scenario of a child with a cardiac arrest at school, having an AED readily accessible could save several minutes before the 911 medics arrive, and that means the child's chances of survival are much higher.

AED Myths and FAQs

Is "sudden cardiac arrest" the same thing as a "heart attack?"


A heart attack is a blockage of the blood vessels that supply the heart muscle, and it generally appears as pain in the chest (or other areas). The person will generally be awake and alert, able to describe the symptoms they are experiencing.

​A sudden cardiac arrest is an electrical issue in the heart that causes an abnormal rhythm (or no rhythm). Sudden cardiac arrest often appear without any warning or any symptoms. This event may be the first health issue that a child has ever had, with no other warning signs.

My children don't have heart issues, so why worry?

While it is true that children tend to have fewer health problems, a sudden cardiac arrest can occur in otherwise healthy children without any warning, and often can be the first time that any heart issue is detected.

Additionally, older family members (ie grandparents) often visit schools to watch their children perform or play, so having an AED on the premises will also benefit those individuals.

Why can't I just call 911 and have EMS treat the victim?*

Calling 911 is always the first step in a medical crisis.  EMS respond times can vary due to a number of factors ranging from the city, to confusion between dispatch and 911 caller, and the true time it takes from the time of the 911 call to the time that EMS arrives at the victim’s side with an AED.  Statistics are that “call to shock” times are too often outside of the 5 minute window that a victim has to survive without CPR and an AED.  

The most important piece of information to remember is that a person in cardiac arrest is in a race against the seconds ticking by on the clock. 

Why not learn CPR instead?

You should do both CPR and AED training.

In fact, knowing and performing CPR is generally necessary in order to successfully revive someone with an AED, because the heart will not restart if there is absolutely no oxygen left, no matter how hard it is shocked. For that reason, the AED may tell the rescuer to perform CPR, in order to get some oxygen circulating first.

However, CPR by itself (without an AED) is only able to delay the permanent damage to organs. CPR alone is rarely able to restart a person's heart (some exceptions). That said, everyone should be trained on CPR because it is still very beneficial for the patient because it delays the damage for precious seconds, giving emergency services more time to arrive.

Can AED's harm the children?

When used properly, AED's are extremely safe. The potential benefit for the patient is astronomically high, and the instructions provided by the AED prevent accidental shocks. Additionally, the computer system inside the AED is able to detect scenarios when shocking is not appropriate.

When AED's are installed in public locations, such as schools, they are installed in wall cabinets equipped with alarms, sirens, and lights, so that a large response is immediately initiated whenever anyone opens the cabinet.

If AEDs are so easy to use, why do people need formal training in how to use them?*
An AED operator must know how to recognize the signs of a sudden cardiac arrest, when to activate the EMS system, and how to do CPR. It’s also important for operators to receive formal training on the AED model they will use so that they become familiar with the device and are able to successfully operate it in an emergency. Training also teaches the operator how to avoid potentially hazardous situations.

What if I am untrained? Can I still use the AED?

Yes, but proper training helps to identify when an AED should or should not be used. In the event that someone has a sudden cardiac arrest, a trained responder in the area will take over. However, if there are no trained responders nearby, then bystanders should begin CPR and get an AED. In many cases, removing an AED from the cabinet or hook will set off alarms and sirens, which may notify a trained responder. For information on training courses, see the American Red Cross Training & Certification page, or you may contact us for more information.

AED's have very clear directions, pictures, and verbal instructions that will walk you through each step. These instructions are simple, such as "Now place red pad on patient's left side," with images to guide. Or such as "Analyzing patient. Step back and do not touch patient."

​Should I perform CPR first or apply electrode pads from the AED?*
Start CPR immediately and have someone else get the AED. When the AED arrives, immediately open the device package and follow the voice commands. At this point, getting the AED attached correctly is the top priority. Apply the electrode pads to the victim's bare chest and follow the voice prompts and messages of the AED. It will tell you when to resume CPR.

Can I be sued using an AED?*
To date there has never been a case where someone was held liable for using an AED, but as you know, anyone can be sued. Likewise, most states have passed “Good Samaritan” laws protecting rescuers from lawsuits.

If CPR and AEDs are so effective, why are they not mandatory in schools?

As of September 2018, AEDs are now mandatory on any California school campus that has an athletics program (essentially all school campuses). This puts California among the 25 states with laws requiring AEDs. However, CPR/AED training is not required in California schools, despite this being a proven way to reduce cardiac deaths in the community. There are 35 states that currently require CPR/AED education as a high school graduation requirement, and we hope to see change in this requirement for California soon. For now, we hope to spread more awareness in the community of these issues, so that it gets the attention it deserves.

If these issues interest you, please contact us for more information or to get involved. Here is a website focused on AED requirements by state.

*Some questions were taken from the American Heart Association Heartsaver Q&A and AED4Life.

For more information, here is a link to a fact sheet: American Heart Association: What is an Automated External Defibrillator?

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