Learn life-saving first aid with St John Ambulance Cymru

CPR for Adults: Learn How to Perform Cardiopulmonary Resuscitation


There is separate guidance on how to perform CPR on an infant (up to 1 year old) or child (1-18 years old). For CPR for adults please follow the steps below:

If you find an adult collapsed or unresponsive, you should:
  • Assess any dangers to yourself and the casualty. Move items if necessary to make the area safe.
  • If safe to approach the casualty, assess the casualty’s response levels by gently shaking the shoulders and shouting ‘’are you all right?’’
  • If there is no response e.g. the casualty does not move, talk, or open their eyes - shout for help.


If the casualty is on their front you will need to get them onto their back. Once on their back, open the airway:
  • Place one hand on the casualty’s forehead and tilt the head back gently.
  • Place your index and middle finger of your other hand onto the casualty’s chin and lift. This will lift the casualty’s tongue from the back of their airway.
  • With the head tilt and chin lift maintained, assess the casualty for breathing.
  • Place your ear over the casualty’s mouth and nose and listen for breathing and feeling for breath on your cheek. At the same time look at he casualty’s chest and stomach to see if it is rising and falling. Take no more than 10 seconds to assess breathing.


If the casualty is not breathing normally or you are unsure, start CPR.

If you suspect the casualty is Covid-19 positive, before starting chest compressions use a towel or piece of clothing and lay it over the mouth and nose of the casualty.

While performing chest compressions ask a bystander to call 999/112. If you are alone call 999/112 and put your phone on loud speaker so that you can talk to the operator while performing chest compressions. The ambulance call handler will tell you where the nearest automated external defibrillator (AED) is. If someone is with you, ask them to fetch it and bring it back.

Do not leave the person to fetch an AED if you are on your own as the ambulance crew will have one when they arrive.


To perform chest compressions:
  • Kneel by the casualty and put the heel of one hand in the centre of their chest. Place your other hand on top of the first. Interlock your fingers making sure they don't touch the ribs.
  • Keep your arms straight and lean over the casualty. Press down hard, to a depth of about 5-6cm before releasing the pressure, allowing the chest to fully recoil.
  • Complete 30 chest compressions at a rate of 100-120 beats per minute. The beat of the song 'Staying Alive' can help you keep between this range.
  • Following 30 chest compressions give two rescue breaths if you are willing and able.


To give rescue breaths:
  • Open the airway as described above, pinch the casualty’s nostrils closed with your finger and thumb.
  • Gently pull down on the casualty’s chin to open their mouth.
  • Seal your mouth over the casualty’s mouth and blow steadily for no more than 1 second or until you see the chest rise.
  • Repeat this twice to give two rescue breaths.

If you are unwilling or unable to give rescue breaths, perform chest compression only CPR, as this is better than nothing. Push down hard and then release twice per second, and don’t stop.


Give 30 chest compressions followed by 2 rescue breaths and continue this until:
  • Further qualified assistance arrives and takes over
  • The casualty starts to show signs of life (breathing, talking)
  • You become tired and need to swap with another bystander
  • A defibrillator is ready to be used.


You can download our digital first aid guide which contains this information as well as other lifesaving first aid information.

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