CPR:

• Understands the chain of survival, and that a casualty is unlikely to recover with CPR alone
• Understands the aim of CPR is to maintain oxygen perfusion to the brain and other vital organs
• Understands that an unresponsive casualty with absent or abnormal breathing requires CPR
• Understands that agonal breathing is not normal breathing
• Can perform CPR effectively to the current protocol
• Understands that a trained first aider should do rescue breaths as well as compressions, if possible
• Understands that vomiting during CPR is common and the action to take
• Understands that a Distress Alert and Mayday should be sent, or help summoned by phone, before CPR is started.
• Understands how an AED is used, and that they are completely safe
• Understands that an AED should be used as soon as possible
• Understands when CPR should be stopped 

The chain of survival detailed by the UK Resuscitation Council lays out four stages to survival. The first 3 are within the remit of a first aider.

1) EARLY RECOGNITION & CALL FOR HELP

2) EARLY CPR

Immediate CPR can double or quadruple survival

3) EARLY DEFIBRILLATION

Use of an AED / Defibrillator within 3 - 5 minutes of collapse can increase survival rates as high as 50 - 70%.  

4) POST RESUS CARE

Falls outside of the skills of a first aider - requires professional airway management, medication and care 

CPR stands for cardiopulmonary resuscitation. It combines chest compressions and rescue breaths to give a person the best chance of survival following a cardiac arrest.

Someone who is not conscious and not breathing normally or doesn't have a pulse

Anyone with training

To someone who is unconscious, not responsive and not breathing or gasping for air

If you find someone collapsed, make sure it's safe to approach, check if they respond by gently shaking their shoulders and asking them loudly are they ok. If they don't respond, shout for help and open their airway by gently tilting the casualty's head back and lifting their chin. Look, listen and feel for up to 10 seconds for normal breathing (ignore occasional, irregular gasps - these are common in the early stages of cardiac arrest). 

If they are not breathing normally, ask a helper to call 999 or 112 for an ambulance (ashore) or Mayday Distress Alert & Voice Call (afloat) while you start CPR. Ask a helper to find and bring a defibrillator / AED, if available.

If you are alone:

AFLOAT: 

• Make a Mayday Distress Alert & Voice Call before commencing CPR, ensure to emphasise that you are alone within the Mayday voice call, if you have a handheld VHF keep it with you, if a fixed set, turn the volume up enough that you can hear it. 

ASHORE:

• use the hands-free speaker on a phone so you can start CPR while speaking to ambulance control 
• Ask your helper to put the phone on speaker and hold it out towards you
• Do not leave the casualty to look for a defibrillator yourself.  If there is someone else with you, send them to get one.  The emergency medical advisor can tell them where the nearest defibrillator/AED is.
• If you're on your own, use the hands-free speaker on a phone so you can start CPR while speaking to ambulance control (Ashore).

Start chest compressions. Ideally this should be on a firm surface so if, for example, they are on a bed, and if it is safe for you to do so, move them to the floor.

• Kneel close to the casualty and put the heel of your hand on the middle of their chest. Put your other hand on top of your first hand and if you can, interlock your fingers.  
• Lean forwards so your shoulders are over your hands, keep your arms straight and press down hard, to a depth of about 5-6cm before releasing the pressure and allowing the chest to come back up.
• Push at a rate of 100 to 120 per minute.
• Listen to instructions from the ambulance controller, who will tell you what to do and help you to push at the right speed.

After 30 compressions, provide 2 rescue breaths. If you are unable or unwilling to provide rescue breaths, give continuous chest compressions.

• Tilt the casualty's head backwards, lift their chin and pinch the soft part of their nose closed.
• Take a breath and put your mouth around the person's mouth, to make a seal.
• Blow into their mouth steadily and firmly for up to one second, until the chest rises.
• Remove your mouth and watch the chest fall.
• This is a rescue breath, do this twice.

It is important not to interrupt chest compressions for too long so each time you attempt rescue breaths, stick to two attempts to get the breaths in.  If one or both don't work, return to chest compressions.

Keep alternating 30 compressions with 2 breaths (30:2) 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 swap every one to two minutes, but try to minimise interruptions to chest compressions)
• A defibrillator is ready to be used

NOTE: If the casualty begins to gurgle or vomit whilst you're giving CPR briefly roll them onto their side and allow the fluid / vomit to drain out then resume CPR