CPR and AED: the first four minutes that make the difference

Cardiac arrest offers no second chance to think. Within a few minutes without oxygen-rich blood, irreversible brain damage can occur — and in those very first minutes, you, not the ambulance, are the only one who can do something.

Why the clock starts ticking immediately

As soon as the heart stops beating, the oxygen supply to the brain also stops. Even in the best circumstances, an ambulance needs a few minutes to reach the scene. In the meantime, chest compressions maintain minimal blood circulation — not a replacement for a beating heart, but a crucial bridge.

What to do in practice

1. Briefly check responsiveness. Is the person unresponsive? Call 112 immediately — or have someone else call.
2. Check breathing and follow the 112 dispatcher's instructions.
3. Start chest compressions if breathing is absent or abnormal: firm, fast and in the centre of the chest. According to the latest guidelines (ERC Guidelines 2025), continuous chest compressions, without rescue breaths, are a perfectly good approach for anyone without training.
4. Have someone fetch an AED as soon as possible, and follow the voice instructions — the device guides you throughout.
5. Keep going until professional help takes over.

The AED: your greatest ally

An AED identifies for itself whether a shock is needed and will never deliver one if it is unsafe or unnecessary. So you cannot do anything wrong with it — but you can do something right by simply using it as soon as it is available.

Practice and familiarity make the difference

Precisely because this is a moment with no time to think, familiarity with the steps is crucial. An annual refresher and a clear action card on site reduce the chance of panic taking over.

Source: Resuscitation Council UK, summary of ERC Guidelines 2025 · Resuscitation Council UK — Adult basic life support 2025