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
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
Who may use the AED?
Only those who have been
trained to use the AED and are under medical oversight may use it.
The training course for CPR and
AED is approximately eight 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. If they are previously trained in CPR, the
course is only four hours.
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
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
noone 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 medical direction,
training, continuing education, quality management, documentation
and equipment maintenance.
Additional community support
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
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, and/or
they must have medical oversight.
Using an AED is no different
from performing other medical act or first aid: if AED operators
perform as they are trained to perform, they are protected. Noone in
Canada has ever been sued for using an AED.
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 have medical
oversight, are properly trained and that protocols for continued
training, operation and equipment maintenance are in place.
Who will provide initial
Communities may customize their
training program. One or more community members can be trained by a
qualified instructor. Once trained, these community members may be
asked to provide training to others within the community.
Initial training requires
personal instruction and supervision, but training videos are
available so that learners may review procedures as often as they
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
Does having an AED in the
community reduce the need to eat a healthy diet or take care of your
body in other ways?
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
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.
What cost/benefit information
is available for AEDs?
Financial costs include
one-time purchase of the AED (about $5,000 for a basic machine, and
up to $12,000 for an advanced monitor/defibrillator) 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
Who is responsible for
The community worker
responsible for medical supplies and equipment should include the
AED and its supplies in a regular schedule of checks and
Buying a community AED
About our community
What do we need to know about
our community before deciding whether to buy an AED?
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
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.
Community's health priorities
What are our community's health
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 is going to pay?
Who is going to pay for the
The community that acquires the
AED will pay for it. In some areas, service clubs and businesses are
helping to provide funds to purchase AEDs and training.
Who will need training?
Who will need training?
Depending on the population and
location of the community, it might be most efficient to send one or
two health workers or first responders for initial training as AED
instructors, so that they may return to the community to train other
community members. Community members who have been trained as
qualified AED instructors can provide personal instruction and
supervision to community AED providers and can also organize a
system of on-going review, using training videotapes and regularly
scheduled practice sessions. However, they must have medical
A physician, nurse or
paramedic could be asked to provide regular continuing education
sessions to review procedure and assess performance.
Who will provide community
education before a decision is made about the appropriateness of
The answers provided in this
section address many questions that community members have about
AEDs. Your provincial Heart and Stroke Foundation can provide
further information and other contacts.
Decision making process
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.
No AED in the community
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.
What else is needed?
What else is needed in our
community to effectively use the AED?
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
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.
Other uses of AED
Can an AED be used for
anything other than cardiac arrest?
The basic AED is used only in
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.
Effectiveness without 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.