Emergency Care / CPR - Automated External Defibrillation

For more information about AEDs, Ask The Expert. To learn more about emergency cardiac care or CPR, call 1-888-HSF-INFO (1-888-473-4636).

What is an AED and how does it work?
Community AED Programs
Initial training
Cost/benefit information
Effectiveness of AED

What is an AED and how does it work?

What is an AED?

 An Automated External Defibrillator (AED) is a machine that analyses and looks for shockable heart rhythms, advises the rescuer of the need for defibrillation and delivers that shock, if needed.

What disease is it for?
The AED doesn't treat any disease. Its purpose is to reset a heart that has stopped beating effectively, usually caused by an abnormal heart rhythm called ventricular fibrillation (VF). The AED is applied to the victim of sudden cardiac arrest, a condition where the heart unexpectedly and abruptly quits beating. This could also be caused by a lightning strike, electrocution, hypothermia, kidney failure or physical injury (trauma).

How does the AED work?
Adhesive pads attached to wires that connect to the AED are placed on the patient's chest, and the machine delivers an electrical shock through the body to the heart.

The AED is one vital link in a chain of events called the "Chain of Survival". First of all, someone must recognize that there is an emergency and call for help. While waiting for help to arrive CPR must be started. As soon as an AED is available, it can be used. The next step is advanced medical care.

Who may use the AED?
The training course for CPR includes training in and AED is approximately 4-5 hours and can be provided to community members who have an interest in learning. Learners do not require previous special skills, first aid experience or more than a basic level of education.

Most commonly, community health workers of all levels can be trained to use the AED, but trainees could also include volunteers in the community who are interested, willing to learn and willing to participate in emergency response. For the AED to be most effective, all members of the community should learn when and how to call for medical help using 911 or the local emergency number, and how to perform CPR while waiting for the AED to arrive.

Does it always work?

 No. Sometimes the heart cannot be reset, even with more than one shock. An AED doesn't fix the disease or injury that caused the heart to stop. It sometimes can reset the heart of a person whose heart has stopped and who would otherwise die.

But, it won't save everyone. It must be used within a few minutes after the heart has stopped - the sooner, the better. Some hearts are too damaged, stopped or cannot be reset, but, without a defibrillator, all people whose hearts have stopped beating effectively will die.

Could someone be hurt by an AED?
A patient who has no pulse cannot be hurt and might be saved.

A trained operator who uses the AED correctly cannot be hurt. It is very important to make sure no one is touching the victim. A serious injury to an AED operator has never been reported.

How does shocking a person affect that person overall? Are there lasting effects?
The electric shock from an AED passes out of the body, with no lasting effect beyond the effect of stimulating and resetting the heart.

Can we just buy an AED?
To be effective, AEDs and trained responders must be part of a planned community program in cooperation with the emergency medical services system. The AED is one component of an overall program including training, continuing education, quality management, documentation and equipment maintenance.

What additional community supports are needed?

 The AED can reset a heart, but it has limitations. If a person collapses because his heart has stopped beating effectively, we have only 6 - 8 minutes at best, to reset the heart with the AED. If someone sees the person collapse and performs CPR (rescue breathing and chest compressions) while waiting for the AED to arrive, we have a little extra time - perhaps up to 15 minutes in all - to reset the heart with the AED.

Before deciding to purchase an AED, the community should be committed to learning the signs and symptoms of heart attack, the importance of promptly seeking treatment for heart attack and when and how to perform CPR. Everyone in the community must know the emergency number to call for help. There should always be an AED operator ready to respond instantly to an emergency call.

Our community does not have a doctor. Where can we get support for community members who use an AED?

If medical expertise is not available in the community, communication links can be established among communities that use AEDs, and to larger Emergency Medical Systems that use AEDs frequently and can provide advice.

Are nurses and workers covered for liability if they use an AED?
For health care workers whose scope of practise is defined by regulation, scope of practise guidelines may need to be updated to include defibrillation.

Using an AED is no different from performing any emergency care or first aid: if AED operators perform as they are trained to perform, they are protected. No one in Canada has ever been sued for using an AED.

Legal implications

What are the legal implications of having an AED in the community?
Along with the purchase of the AED, the community must assure that operators are properly trained and that protocols for continued training, operation and equipment maintenance are in place.

Initial training

Who will provide initial training?
Communities may customize their training program. One or more community members can be trained by a qualified CPR instructor.

Initial training requires personal instruction and supervision, but training videos are available so that learners may review procedures as often as they wish.

Is ongoing training necessary?
Yes. It is not enough to learn how to use the AED. Using the AED is a skill like any other: it must be practised regularly or it will be forgotten. Once trained, AED operators should regularly view a training video, and should frequently practise the procedures in order to keep up their skills. Practise should occur at least every 90 days, particularly for people who do not regularly use an AED.

Where is it going to be used?
Most commonly, the AED is taken to the patient whose heart has stopped beating effectively. The AED can be kept in a central place in the community or it can be kept by the AED operator on-call. In some communities, the patient could be brought to the machine.

Healthy diet and AEDs

 No. AED doesn't prevent heart disease and it doesn't treat heart disease. When it works, the best it can do is reset a stopped heart and give the patient one more chance to live. Healthy habits such as being smoke free, getting exercise and healthy eating are important in preventing heart disease.

What other communities are using AEDs? What has been their experience?
AEDs have been available for about 10 years. Every major city in Canada as well as some smaller centres have AEDs. Some cities have AEDs only on ambulances, while others have them on fire trucks or in police cars as well. AEDs can be placed in other public locations, such as public buildings, recreation centres or stadiums, and the staff can be trained to operate the AED.

Adding AEDs to the community does increase survival from cardiac arrest, but the rate of survival depends on many factors.

Communities that have the best results do more than just purchase AEDs:

• they make sure that people know the signs and symptoms of heart attack;
• they make it easy for people to get help fast in an emergency;
• they teach CPR to as many people as possible.
  
  

 Financial costs include one-time purchase of the AED (for approximately $5000 or less) and a small ongoing cost for supplies. Training expenses will vary, depending upon the location of the community and the training arrangements. Expenses might include transportation, accommodation, material and course costs, and time away from work.

Depending on the size and health of the community, the AED may be needed once a month or once in five years. When defibrillation is needed, it is the patient's only chance. Without it, a pulseless patient will certainly die.

For an AED to be effective, a continuing commitment to skills and education, and the expenditure of time and energy by health educators is required.

The side benefit of community awareness and education may, by itself, justify ongoing time and energy spent in training about heart attack symptoms, CPR and AED use.

Who is responsible for equipment maintenance?
The community worker responsible for medical supplies and equipment should include the AED and its supplies in a regular schedule of checks and maintenance.

About our community

 The AED is used to reset a heart that suddenly stops beating effectively (cardiac arrest), but it must normally be used within 10 minutes. People who suffer cardiac arrest have the best chance of surviving if someone sees them collapse, calls for help and performs CPR until the AED arrives within minutes.

Even under the best of circumstances, not every heart can be reset.

In communities where the population is small or very spread out (so that it takes more than 10-15 minutes to reach the person needing the AED), an AED may not be effective because it won't reach people in time.

In larger communities, communities with a high rate of heart-related illness (such as diabetes) or a large number of at-risk adults, or communities where there's a nursing station that looks after heart patients awaiting transport, an AED is more likely to be effective. Its effectiveness will be increased if community members know the signs and symptoms of heart attack, know CPR and are encouraged to call for help early.

What are our community's health priorities?
In deciding how to spend its health budget, the community will want to identify the most common health problems and the most serious health problems in the community, as well as considering which problems can be prevented and which can be treated. It is appropriate for various communities to come to different conclusions about their need for an AED. In some communities, an AED will be effective. In others, it may not.

Who will provide community education before a decision is made about the appropriateness of AEDs?
The answers provided in this section address many questions that community members have about AEDs. For further information, Ask The Expert.

What decision making process will be used?
The community will need to decide whether or not to set up a program and purchase an AED. The process the community will choose to make this decision may be the same one that is used to make other health budget allocation decisions, or another process may be chosen.

What will happen if we don't have an AED in our community?
If defibrillation is not available quickly after cardiac arrest, the chance of survival is minimal. Having an AED available quickly will save the lives of some people who suffer a cardiac arrest.

 
The AED is a necessary link in the Chain of Survival from cardiac arrest, but it is only one link. There are other things that the community can do to increase survival. Community members must be taught the signs and symptoms of heart attack, so that they will seek help early. Community members must learn CPR so that if they witness a cardiac arrest, they can provide the patient with a few extra minutes for help to get there. Community members must know the emergency number to call to access the AED. A trained operator must be standing by at all times, ready to take the AED to the patient when called. If a person in cardiac arrest is resuscitated by the AED, the person must be transported to a hospital for advanced care.

Can an AED be effective in this community?
An AED will save a percentage of the witnessed cardiac arrests which are reached within a few minutes. If cardiac arrests in your community are most likely to be witnessed and occur in close proximity to where the AED is located, the AED will be effective. If cardiac arrests usually occur more than 15 minutes away from an AED, it will not be effective. The rate of success is determined by how soon the AED reaches the cardiac arrest patient, and whether or not the patient has received CPR.

Can an AED be used for anything other than cardiac arrest?
The basic AED is used only in cardiac arrest.

A more advanced model of AED includes a heart monitor which a physician or specially trained health care professional can use to observe the rhythm of the heart. Using a heart monitor, medical personnel would be able to give early treatment with "blood clot dissolving" drugs or treat heart rhythm problems which would otherwise need to wait for treatment until arrival at a hospital. The usefulness of the monitor, however, depends upon the level of medical support in the community.

Can a basic AED be effective without a program of community awareness, CPR, emergency phone access, and full-time operator availability?
Maybe. If the community has a medical facility that cares for heart patients, some of whom may be awaiting transport to more advanced care, there may be a need for a basic AED that stays in that location to be operated by the medical or nursing staff in case of cardiac arrest.

For more information about AEDs, Ask The Expert. To learn more about emergency cardiac care or CPR, call 1-888-HSF-INFO (1-888-473-4636).