Emergency advice

Cardiac arrest:

  1. Call 999.
  2. Start CPR immediately. Do not perform rescue breaths
  3. Attach and follow the defibrillator voice prompts while continuing CPR. 

What is a cardiac arrest?

A cardiac arrest happens when someone’s heart stops.

If someone has become unresponsive and they are not breathing normally, they could be in cardiac arrest and you need to act quickly. Call 999 or 112 for emergency help and start CPR, using a defibrillator if available.

Signs and symptoms

If someone has a cardiac arrest, they may:

  • be unresponsive.
  • not be breathing normally (taking slow, gasping, sometimes noisy breaths).
  • show no movement or signs of life. 

For more information on this topic visit the Resuscitation Council UK website.

What to do

  1. First aid - call 999 or 112 for emergency help

    If you find someone collapsed, you should first perform a primary survey (check for a response, open their airway and look for normal breathing and signs of life for no more than 10 seconds). If they are unresponsive and not breathing normally, shout for help. 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.

    • If you are on your own, use the hands-free speaker on a phone so you can start CPR while speaking to ambulance control
    • Do not leave the casualty to look for a defibrillator yourself.  If there's someone else there, they can go and collect one.  Otherwise, the ambulance will bring one.
  2. Cardiac arrest first aid - start CPR

    Start CPR. Kneel by the casualty and put the heel of your hand in the middle of their chest.

    Put 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 4-6 cm, then allow the chest to come back up.

    • Push at a rate of 100-120 per minute (The beat of the song "Staying Alive" can help you keep the right rate).  The ambulance emergency medical advisor will tell you the rate to push at too.
  3. Cardiac arrest first aid - repeat compressions 30 times

    After 30 chest compressions, you should ideally give two rescue breaths. This is done by placing one hand on the forehead and two fingers (of your other hand) underneath the tip of the chin. Using the hand on the forehead, pinch the casualty's nose with your finger and thumb, allowing the casualty's mouth to fall open. Take a breath and place your lips around the casualty's mouth, forming a seal. Blow into the casualty's mouth until the chest rises. 

    Repeat 30 chest compressions at a rate of 100-120 compressions per minute, to 2 breaths.  If you can't give two rescue breaths, just give continuous chest compressions.

    Continue to perform CPR until:  

    • emergency help arrives and takes over
    • the person starts showing signs of life and starts to breathe normally
    • you are too exhausted to continue - if there is a helper, you should change over every one-to-two minutes.  Try to minimise interruptions to chest compressions.
    • a defibrillator is ready to be used.
  4. Cardiac arrest first aid - switch on the defibrillator and follow voice prompts

    When the helper returns with a defibrillator, ask them to switch it on and take the pads out while you continue with CPR. They should remove or cut through clothing to get to the casualty's bare chest. They also need to wipe away any sweat.

    • The defibrillator will give voice prompts on what to do.
  5. Cardiac arrest first aid - apply the pads

    They should attach the pads to the casualty’s chest by removing the backing paper. Applying the pads in the positions shown.

    • The first pad should be on the upper right side below the collar bone.
    • The second pad should be on the casualty’s left side below and in line with the arm pit.
  6. Cardiac arrest first aid - follow the visual and verbal prompts from the defibrillator

    The defibrillator will analyse the heart's rhythm. Stop CPR, and make sure no one is touching the casualty. It will then give a series of visual and verbal prompts that should be followed.

    • 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.
  7. Cardiac arrest first aid - if casualty becomes responsive, put them in the recovery position

    If the casualty shows signs of becoming responsive such as coughing, opening their eyes, speaking, or starts to breathe normally, put them in the recovery position.

    Leave the defibrillator attached. Monitor their level of response and prepare to give CPR again if necessary.

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