Understanding Automated External Defibrillators (AEDs)
Defibrillation is the definitive treatment for sudden cardiac arrest
commonly caused by ventricular fibrillation.
This in turn arises from a heart attack,
drowning, electric shock or other problems.
It is important that defibrillation be done
soon and automated
external defibrillators (AED) are made to be
readily available and easy to use.
They are designed to be less expensive than
traditional defibrillators and have voice guided
prompting to encourage their use by non-medical
work by analyzing the patients’ electrocardiogram
which is sensed through the adhesive defibrillator
pads and prompting the operator through the
necessary steps from applying the pads to performing
CPR if needed.
AEDs look for ventricular fibrillation and
rapid ventricular tachycardia associated with a pulse-less unresponsive patient.
Biphasic defibrillation waveforms are most
commonly administered by most AEDs.
Some models make a distinction between
being automatic and semi-automatic. Semi-automatic
in this instance refers to the user having to
manually push the shock button.
Truly automatic units will administer the
shock without needing an operator.
Some units will feature a monitor that
will display the electrocardiogram.
Units will vary in the amount of coaching
and prompting they provide for the user through the
CPR process. Those
AEDs which feature more prompting may be more
suitable for so-called “Public Access
Defibrillation” where users untrained in life
support would be using them.
Adult Cardiopulmonary Resuscitation (CPR) with
Be sure to check with the American Heart
Association for the latest CPR guidelines
Adult CPR is for victims aged 8 and older.
CPR basically involves giving chest
compressions and breaths to the victim.
When an AED is available, the rescuer will
usually be guided through this process by the AED. The AED
will instruct on CPR application and will also
analyze and advise on shocking the patient when
the recommendation for adults is to give 2 breaths
followed by 30 compressions.
The compression rate is 100 per minute with
a chest compression depth of 1.5 to 2 inches.
The entire CPR process with an AED comprises several steps in a specific
sequence which most AEDs will prompt you through:
Securing the area.
Checking for patient responsiveness.
Calling for help if the patient is non-responsive or
(Tilt back head to open the airway and
watch for signs of breathing).
Give 2 breaths if the victim is not breathing.
Give 30 chest compressions.
Repeat these last 2 steps until an AED is
connected or the victim starts to move.
Apply adhesive defibrillation pads.
Wait for the AED to analyze the electrocardiogram.
Shock the patient if the AED indicates to do so.
erform 2 minutes of CPR.
After 2 minutes, stop CPR and allow the AED to
analyze the electrocardiogram again.
Repeat step number 10 and 11 or if no shock advised,
start CPR if appropriate.
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