Life support: CPR, the AED and the recovery position

30 min

Two questions decide everything

When a player collapses, a first aider has to answer two questions quickly. Does the person respond? Are they breathing normally? If the answer to both is no, the heart has almost certainly stopped (cardiac arrest), and every minute without chest compressions and a shock from a defibrillator lowers the chance of survival; the ERC estimates that each minute's delay in defibrillation cuts it by about 10%. If the person does not respond but is breathing normally, the danger is different: the tongue, vomit or blood may block the airway, and the recovery position keeps it clear. This lesson follows the ERC Guidelines 2025 for both.

Definition

Cardiac arrest: the sudden stopping of the heart's pumping, so that the person becomes unresponsive and stops breathing normally.

Agonal breathing: slow, noisy, gasping breaths that can occur in the first minutes after cardiac arrest. It is not normal breathing.

CPR (cardiopulmonary resuscitation): chest compressions, with or without rescue breaths, that keep blood flowing to the brain and heart.

AED (automated external defibrillator): a portable device that analyses the heart's rhythm and, if needed, gives an electric shock, guiding the user by voice.

Recovery position: a stable side-lying position that keeps the airway open in a person who is unresponsive but breathing normally.

CPR, step by step (ERC 2025)

Check for a response. Tap the shoulders and ask loudly, "Are you OK?"
Check for normal breathing. Open the airway (head tilt, chin lift) and look, listen and feel for no more than 10 seconds. Brief jerking movements, like a seizure, and gasping can happen at the start of a cardiac arrest: once any movement stops, check breathing at once.
Call 912 if the person is unresponsive and not breathing normally. Put the phone on speaker and send someone to fetch an AED. The call-taker will help you recognise cardiac arrest and will guide you through CPR.
Start chest compressions. Kneel beside the person, who should be on a firm surface. Put the heel of one hand on the centre of the chest and the other hand on top; keep your arms straight. Push down 5 to 6 cm at a rate of 100 to 120 per minute, let the chest rise fully after each push, and keep pauses as short as possible.
Rescue breaths, if trained and willing. Give 30 compressions, then 2 breaths, each lasting about 1 second and just enough to make the chest rise. If you are not trained, or not able or willing to give breaths, give continuous compressions only, as the call-taker directs: this is far better than doing nothing.
Use the AED as soon as it arrives. Switch it on and follow its voice prompts: stick the pads to the bare chest, make sure nobody touches the person while it analyses or shocks, and restart compressions straight away when it tells you.
Keep going until professional help takes over or tells you to stop, or the person clearly shows signs of life such as waking, moving and breathing normally. Do not worry about hurting the person: trying to save a life matters more.

CPR at a glance (adult)	ERC 2025
Hand position	Centre of the chest
Depth	5 to 6 cm
Rate	100 to 120 compressions per minute
Ratio, if trained and willing	30 compressions : 2 breaths
Untrained or unwilling to give breaths	Continuous compressions, guided by the call-taker
AED	As soon as one is available; follow the prompts

The recovery position

When to use it. Use the recovery position for a person whose responsiveness is reduced for a reason that is not an injury, for example after fainting or a seizure, who is breathing normally and does not need CPR. Do not use it if the person has agonal breathing (start CPR instead) or has suffered trauma, such as a heavy fall or collision: keep an injured person on their back and keep the head and neck still.

How (ERC 2025):

Kneel beside the person and make sure both legs are straight.
Place the arm nearest you out at a right angle to the body; it may be straight or bent at the elbow.
Bring the far arm across the chest and hold the back of that hand against the cheek nearest you.
With your other hand, grasp the far leg just above the knee and lift the knee so the foot stays on the ground.
Keeping the hand pressed to the cheek, pull on the bent leg to roll the person towards you onto their side.
Adjust the upper leg so that both the hip and the knee are bent at right angles.
Tilt the head back to keep the airway open, adjusting the hand under the cheek so the face points slightly down and fluid can drain from the mouth.
Check breathing regularly. If it becomes abnormal or stops, roll the person onto their back, call 912 and start CPR. Leave the person alone only if you must go for help.

Worked example 1: three casualties, three decisions

During a hot-weather athletics session, a girl faints. She does not respond to your voice, but she is breathing normally, and she did not hit anything as she fell. Recovery position, call 912, and keep checking her breathing.
A rugby player lies still after a heavy tackle. He is unresponsive but breathing normally. Because of the trauma, do not roll him: keep him on his back, hold his head and neck still, call 912 and watch his breathing.
A spectator collapses. She does not respond and gives an occasional noisy gasp. Gasping is agonal breathing, not normal breathing: call 912 and start CPR, and send for an AED.

Worked example

Worked example 2: how many compressions in a minute? A trained first aider compresses at 110 per minute and takes 5 seconds to give the 2 breaths after each 30 compressions.

Time for 30 compressions: $\frac{30}{110} \times 60 = 16.4\,\mathrm{s}$ .
One cycle of 30:2: $16.4 + 5 = 21.4\,\mathrm{s}$ , so a minute holds $\frac{60}{21.4} = 2.8$ cycles.
Compressions per minute: $2.8 \times 30 = 84$ , against 110 with compression-only CPR.
Analysis: every pause costs compressions, which is why the ERC says breaths must be quick and pauses short. The breaths still add oxygen, so a trained, willing rescuer gives 30:2; an untrained rescuer gives continuous compressions.

Video: "First Aid Training: CPR", St John Ambulance. Watch the hand position, the straight arms and the depth of each push. The video gives UK emergency numbers: in Rwanda, call 912.

Warning

Common mistakes. Waiting to be sure: gasping is not breathing, so start CPR. Pressing too gently: 5 to 6 cm is deeper than most beginners expect. Doing CPR on a soft mattress: move the person to the floor if you can. Rolling a person with a possible neck injury into the recovery position. Stopping CPR to check for a pulse: keep going until help takes over or the person shows clear signs of life. Practise only on a manikin, never on a person who is breathing.

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Practice

What two checks tell you that a person may be in cardiac arrest?
State the depth and rate of chest compressions for an adult.
What should an untrained bystander do if they are unwilling to give rescue breaths?
When should the AED be used?
Give two situations in which you must NOT use the recovery position.
Put these recovery-position steps in order: roll towards you; bend the far knee; arm nearest you at a right angle; tilt the head back; far hand against the cheek.
A rescuer compresses at 100 per minute and takes 8 seconds for each pair of breaths. Calculate the number of compressions given in one minute of 30:2 CPR.
Explain why the ERC asks call-takers to give CPR instructions on every call about a possible cardiac arrest.

Show answersHide answers

The person does not respond, and is not breathing normally.
5 to 6 cm, at 100 to 120 compressions per minute.
Give continuous chest compressions without breaths, following the call-taker's instructions.
As soon as one arrives: switch it on and follow its prompts, while CPR continues until the pads are on.
Any two: agonal (gasping) or abnormal breathing, when CPR is needed; after trauma such as a heavy fall or collision, when the person stays on their back with the neck kept still.
Arm nearest you at a right angle; far hand against the cheek; bend the far knee; roll towards you; tilt the head back.
30 compressions take $\frac{30}{100} \times 60 = 18\,\mathrm{s}$ ; a cycle takes $18 + 8 = 26\,\mathrm{s}$ ; $\frac{60}{26} = 2.3$ cycles, so about $2.3 \times 30 = 69$ compressions per minute.
Bystanders often do not recognise cardiac arrest or do not know what to do; call-takers are trained to recognise it from the caller's answers and to coach the caller through compressions, so CPR starts sooner and survival improves.

Remember

Unresponsive and not breathing normally: call 912, start CPR, send for an AED.
Centre of the chest, 5 to 6 cm, 100 to 120 per minute, full recoil, few pauses.
30:2 if trained and willing; otherwise compressions only, as the call-taker directs.
Recovery position: unresponsive, breathing normally, no injury. Keep checking breathing.
Trauma: keep on the back, head and neck still.

Sources and credits

ERC Guidelines 2025, European Resuscitation Council: Adult Basic Life Support and The ERC Guidelines 2025 on Resuscitation for Everyone (CPR steps, depth, rate, 30:2, compression-only CPR, AED, the 10% per minute figure); summarised, not copied.
European Resuscitation Council Guidelines 2025: First Aid, Djärv T and others, Resuscitation 215 (2025) 110752: the recovery position (Fig. 3) and when not to use it; summarised.
Photos: AED on a wall, Kaustrins, Wikimedia Commons, licensed under CC BY-SA 4.0; KM23- Chuuk State Department of Education CPR Training, U.S. Marine Corps, public domain.
Video: "First Aid Training: CPR", St John Ambulance, embedded from YouTube.
Recovery position drawing, CPR table, worked examples and practice: written by Ganzaa.

This lesson adapts CC BY-SA material and is shared under CC BY-SA 4.0.

1Two questions decide everything

2CPR, step by step (ERC 2025)

3The recovery position

Two questions decide everything

CPR, step by step (ERC 2025)

The recovery position