AED
Automated External Defibrillation (AED)
An AED is required for a casualty in cardiac arrest. This is where the heart’s electrical impulses have been interrupted and normally results in a heart rhythm called Ventricular Fibrillation (VF) which is fatal if untreated.
An AED provides a controlled electric shock through the heart muscle to enable it to resume its normal rhythm. It is vitally important to administer this as quickly as possible – for every one-minute delay, the chance of survival can drop by up to 10%.
When using an AED, you or a bystander should continue chest compressions whilst preparing the AED and attaching the sticky pads and only stop chest compressions when advised by the AED.
All AED’s will provide verbal and visual prompts to help you understand what to do and how to use the machine.
Signs & Symptoms
A casualty in cardiac arrest will be unconscious and will not be breathing normally. Be aware of gasping, irregular, agonal gasps when determining if the casualty is breathing. If in doubt assume they are not breathing. The ambulance emergency call handler can help you with this.
Treatment
- Check it is safe for you to approach the casualty then check for a response by shouting and gently shaking their shoulders.
- If they do not respond, you need to immediately call 999/112. If you are alone, use the speakerphone function on your mobile so you can continue assessing the casualty.
- Send someone to fetch an AED if one is available. You can find your nearest public AED at defibfinder.uk. The emergency services will also advise you of the nearest AED.
- Open the airway using a heart tilt, chin lift.
- Look, listen and feel for normal breathing for 10 seconds. Agonal gasps are not signs of normal breathing.
- Start CPR if the casualty is not breathing normally.
- Use the AED as soon as available. Turn on and follow the instructions. A bystander can takeover the CPR whilst you attach the AED.
- If you are unsure whether an AED is needed, attach it to the casualty anyway – the machine won’t shock unless it is necessary.
- Dry the chest area if it is wet and/or quickly shave excessive chest hair that would stop the pads sticking to the skin.
- The pads have pictures to indicate where to stick them. See image below.
- You may need to remove a bra, but if unhappy doing this you can adjust it as in the image below. The underwiring of a bra will not interfere with the AED.
- The AED will analyse the heart rhythm and advise if a shock is required. Stand clear if a shock is advised.
- Press the shock button when prompted (a fully automatic machine will do this for you).
- Regardless of a shock advised or no shock advised prompt the AED will ask you continue with CPR at a rate of 30:2.
- Keep following the instructions given by the AED until professional help arrives.
AED use on children
Adult AED’s can be safely used on children, however many AED’s have Paediatric pads and settings. These should be used on children under 25kg (approximately 8 years of age). The diagram below shows where to place Paediatric AED pads.
If you only have an adult AED and pads it is still better and safe to use them than not to use the AED.
Minor changes are needed when giving CPR to a child or infant, see Child CPR section for details.
If you can only remember the adult sequence of CPR it is still better to follow this than to do nothing at all.
Resuscitation
Related Learning
Chain of Survival