How to use a defibrillator (AED)

What to do

1. 1

   After performing a primary survey, and you find someone is unresponsive and not breathing normally, ask a helper to call 999 or 112 and ask for an ambulance while you start CPR. Ask a helper to find and bring a defibrillator, if available.

   • Do not leave a casualty to look for a defibrillator yourself. If there is someone else there, send them to get one. The emergency call handler will tell them where the nearest defibrillator is.

   • If you're on your own, use the hands-free speaker on a phone so you can start CPR while speaking to the emergency call handler.

2. 2

   When the helper returns with a defibrillator, ask for it to be switched on (some will have an on/off button whilst others will turn on when their case is opened). Once turned on, follow the verbal instructions from the defibrillator.

   Your helper should remove or cut through clothing to get to the casualty's bare chest. Dry the chest if it is wet and place the pads as shown while you continue CPR.

3. 3

   Your helper should attach the pads to the casualty’s chest by removing the backing paper. Apply the pads in the positions shown without stopping chest compressions.

   • For adults, place one AED pad on the upper right side of the chest, just beneath the collarbone, and the other on the lower left side, below the armpit.

   • In the case of infants or smaller children, position one pad in the middle of the chest and the second on their back, between the shoulder blades.

   • Some pads have a sensor that goes under the chest compressor's hands in the middle of the chest. If you have those pads, you will have to briefly stop chest compressions to place the sensor.

4. 4

   Once the pads are on, the defibrillator will tell you to stop CPR and analyse the heart’s rhythm. Make sure no one is touching the casualty. It will then give a series of visual and verbal prompts that you should follow.

   • If the defibrillator tells you that a shock is needed, tell people to stand back. The defibrillator will tell you when to press the shock button. After the shock has been given, the defibrillator will tell you to continue CPR for two minutes before it re-analyses.

   • If the defibrillator tells you that no shock is needed, continue CPR for two minutes before the defibrillator re-analyses.

   • Some defibrillators are fully automated and don't have a shock button. Instead of telling you to press the shock button, they will warn you that they are going to shock the patient, when they have delivered a shock, and - exactly like a semi-automated defibrillator - when to continue chest compressions.

5. 5

   If the casualty shows signs of becoming responsive, such as coughing, opening their eyes, or speaking, and starts to breathe normally, put them in the recovery position. Leave the defibrillator attached. Monitor their level of response and breathing and be prepared to start CPR again, if needed.