AED - Can An Automated External Defibrillator Be Effective At Home?

Nearly 300,000 persons each year die of sudden cardiac arrest (SCA). The estimates suggest that 1/4 to 1/3 of persons who suffer SCA could be saved with optimal emergency care.

Early defibrillation is one of the key components. It is suggested that chances for survival decrease by 10% for every minute that a victim of SCA waits for defibrillation.

Automated external defibrillators (AEDs) are sophisticated computerised devices that deliver defibrillatory shocks to victims of cardiac arrest. To guide rescuers they use voice and visual prompts.

There are two types of AED:

• Semi-automatic
• Fully-automatic.

All AEDs analyse the victim’s rhythm and determine the need for a shock. A semiautomatic AED advises the need for a shock (delivered by the operator when prompted).

Originally designed to be used by those certified in advanced cardiac life support (ACLS) or basic life support (BLS) for patients in transport.

Due to technological improvements, AEDs may now be safely acquired, installed and used in public locations to save victims of sudden cardiac arrest. It's possible for non-medical persons to save the lives of someone in cardiac arrest through the use of AEDs.

An AED is used to urgently diagnose and treat ventricular fibrillation, is attached to a victim’s chest to assess the heart’s rhythm. If appropriate, the device will recommend that a shock be delivered.

A metered electrical charge may restore the heart’s functionality. Without immediate cardiopulmonary resuscitation (CPR), defibrillation is less likely to succeed.

In congested urban areas there is a very good chance emergency medical services (EMS) cannot respond fast enough to save someone in cardiac arrest. The national average response time is 10-12 minutes, so even the best EMS responders could have difficulty arriving in time.

Placement of AEDs to provide for public access defibrillation can shortening the time from collapse to shock for ventricular fibrillation.

Automated external defibrillators are becoming more prominent in public areas such as gated communities, office complexes, sports arenas and any other place where large numbers of people gather.

In simulated emergencies studies have shown that untrained persons can successfully operate an AED, but in actual emergencies it remains unclear how adequately such persons would perform.

AEDs have saved lives in the hands of trained experts, but researchers questioned whether the average people could successfully operate an AED.

For a proper AED operation the American Heart Association (AHA) recognizes four steps:

1. Turn on the AED
2. Place the pads on the victim’s bare chest
3. Stand clear for patient analysis
4. Push the shock button if indicated

This is the standard protocol if the victim with signs of cardiac arrest is unresponsive, not breathing, or has no pulse or sign of circulation.

Standing clear of the patient when analyzing and shocking is critical.

• The AED’s ability to read the patient’s electrical activity during the analysis phase could be altered touching the victim.
• Touching the victim while administering a shock could shock the rescuer.
• Placing incorrectly the defibrillation pads could result in an inadequate or ineffective shock.

An exploratory study^[1] was performed to investigate whether the general population can use AEDs successfully.

Five categories of individuals (ranging from the general population to highly trained surgeons) were identified as subjects, to represent varying degrees of health care training.

1. : General population (None of them had ever seen or operated an AED prior to this study).
2. : First-year dental students (May or may not have had experience with an AED).
3. : Third-year dental students (All been certified in CPR).
4. : Dentists, registered nurses, and registered dental hygienists (Certified in the use of an AED).
5. : Anesthesiologists and surgeons (ACLS certification with AED training).

A CPR mannequin was used as the fibrillating patient. The testing room was set up with the mannequin lying on top of a table, T-shirt on, and the AED lying adjacent to the mannequin.

Results

Category one showed an 80% failure rate, category two a 60% failure rate, category three a 30% failure rate, category four a 20% failure rate, category five a 10% failure rate.

Of the fifty operators tested, 42% failed to successfully defibrillate the victim. Of those failing, 52.4% did not remove the patient’s T-shirt. 28.6% did not place the defibrillating pads correctly, the remaining 14.3% failures were a result of the operator touching the patient while defibrillating.

The data suggests that a person in the general population may not be able to successfully operate an AED, especially in a stressful situation.

As AEDs become more commonplace, the public must be educated on their purpose and use.

The home is the most common location out of hospital of sudden cardiac arrest. It's a challenge for the emergency medical services in such situations to provide timely care. Consequently for patients at risk, home use of an AED might offer an opportunity to improve survival.

In a study which included more than 7,000 patients at risk due to previous heart attacks, it was found that access to a home AED did not significantly improve overall survival.

Despite the study’s findings, in remote areas where quick emergency response was unlikely, home defibrillators might be a worthwhile investment combined with an appropriate preparation.

AED can be bought with or without a prescription.

The Philips HeartStart Defibrillator is the only AED on the market which not require a physician's prescription in order to purchase and can be suited for home use.

Prescription AEDs aren't intended for home use, but rather for installation in public places or for use by emergency crews

If you are going to buy an AED for your home or office then get the training required to use it properly. In case of sudden cardiac arrest it takes more than an AED to save a victim's life.

An AED loses much of it's usefulness without the training, because CPR is a big part of the lifesaving procedure with the AED. Inappropriate use may be harmful or ineffective.

If you own a business with customers and/or employees over 50 years old, get one and get trained. From a liability standpoint this is a wise investment.

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If you don't learn how to use and maintain it properly, an AED will be of little use in an emergency.

• Enroll yourself and your family in a community education class.
• To make sure you're using it correctly, demonstrate to your doctor how you and your family would use it.
• AED works only on certain types of cardiac arrest. Know what steps to take if the AED indicates a shock isn't needed.
• Store your AED in an easily accessible place.
• Learn CPR.

[1] : Automated External Defibrillator Use Among The General Population

    Wayne D. Roccia; Paul E. Modic; Michael A. Cuddy, D.M.D

Rainer Ebert