The life-saving power of AEDs: automatic external defibrillators

A defibrillator is a medical device that can be used to apply an electric shock to a patient to restart their heart or shock it back to its correct rhythm. It is used in emergency situations where a person suffers a cardiac arrest and their heart suddenly stops.

An automatic external defibrillator (AED) is a portable type of defibrillator that can be used by anybody – even those without medical training – to help someone suffering a cardiac arrest. The AED analyses the patient’s heart rhythm and, if necessary, delivers an electric shock to restart the heart or restore its normal rhythm. It will not give an electric shock unless it is necessary, so you cannot harm someone by using an AED on them in an emergency.

AEDs guide the user through each step of the rescue process through simple audio and visual commands. They are often found in large public places and are also carried by paramedics.

An AED is needed in emergency situations where someone requires cardiopulmonary resuscitation (CPR), eg, if they have had a cardiac arrest and their heart has stopped. It should be used as soon as possible.

An AED should only be used on someone who is unresponsive and not breathing normally. However, the AED will automatically determine if an electric shock is needed and will not apply one if it is unnecessary, so you cannot harm someone by using an AED on them.

AEDs can be used by anyone, even those without medical training.

In an emergency situation, follow the DRS ABCD guidelines for CPR and using an AED. It is important to note that an AED does not replace CPR. Start and continue CPR until an AED becomes available or the patient becomes responsive.

DRS ABCD

• D – Danger: Check for danger and ensure the area is safe and free of hazards before continuing.
• R – Response: Check for a response from the patient and whether they are breathing normally.
• S – Send for help: Send for help if the patient is not responding. Call emergency services or shout for assistance and direct someone to do so and ask for an ambulance. Ask bystanders to find any AED located nearby and to bring it back.
• A – Airway: Check that the patient’s airways are clear, by opening their nose, mouth and throat. Remove any foreign matter and blockages, such as vomit, blood or food.
• B – Breathing: Check whether they are breathing normally: look, listen and feel for their breaths. If they are breathing normally, gently roll them onto their side (recovery position). This side position ensures their airways remain open. If they are not breathing normally or at all, start CPR.
• C – CPR: Start CPR, with 30 chest compressions followed by two mouth-to-mouth breaths.
• D – Defibrillator: Continue CPR until an AED becomes available.

Defibrillator: Using an AED

As soon as an AED becomes available, turn it on. It will start giving audio instructions to guide you through the rescue process – listen to and follow these carefully.

• Bare the patient’s chest by removing all clothing (including a bra if present).
• Place the defibrillation pads from the AED on the patient’s bare chest.
• The AED will analyse the patient’s heart rhythm. Do not touch the patient while using the AED, as this could interfere with the AED’s analysis.
• If the AED advises that it will give the patient a shock, stay clear of the patient and do not touch them. Keep your hands raised to indicate to bystanders not to touch the patient.
• After the AED delivers the shock, keep listening for instructions from the AED. The AED may instruct you to continue with CPR until the patient becomes responsive or paramedics arrive, or it may advise you if another shock is required.

AEDs are commonly found in large public places, such as hospitals, shopping centres and gyms. They will be clearly marked. Some workplaces may also have an AED onsite, and AEDs can be purchased for home use. Having an AED readily available means that rapid assistance can be provided to someone suffering cardiac arrest, before paramedics arrive.

An AED, used in conjunction with CPR, can greatly increase the survival chances of someone suffering a cardiac arrest. In fact, if it is used within the first three to five minutes of a cardiac arrest, it can increase the chance of survival by up to 70 per cent.

Importantly, an AED does not replace CPR. CPR should be started immediately on the patient, and continued until an AED becomes available or the patient becomes responsive. If CPR is still necessary after an AED is used, the AED will guide the user through the CPR process.