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The chain of survival, link by link
Recognition and a call, early CPR, early defibrillation, advanced care and recovery. What each link is actually worth, which one the public owns, and where the chain breaks in practice.
CPR in sixty seconds
- Unresponsive and not breathing normally? Gasping is not breathing. Treat it as a cardiac arrest.
- Call 112 (113 in Norway). Speaker on, phone on the floor. Stay on the line — the dispatcher will coach you.
- Push hard and fast in the centre of the chest: 5–6 cm in an adult, 100–120 per minute, letting the chest come all the way back up.
- Send somebody else for a defibrillator. Do not go yourself unless it is seconds away. Keep compressing.
- Turn the device on and do what it says. It decides whether to shock. After a shock, go straight back to compressions.
This is a reference written for bystanders, not a diagnosis, a training course or medical advice. It cannot tell you what is wrong with a particular person, and it does not replace the dispatcher on the other end of an emergency call — they can see what is near you and they will talk you through it. If you are worried about your own heart, or about a symptom, that is a conversation with a clinician rather than a page on a website.
A chain, because the weakest link sets the outcome
The image is old and still the best one available: survival from out-of-hospital cardiac arrest depends on a sequence of actions performed by different people, and the whole sequence is only as strong as its weakest step. World-class hospital care cannot rescue a patient who got no compressions for twelve minutes, and perfect bystander CPR cannot substitute for a defibrillator when the rhythm is fibrillating. The first three links belong to whoever happens to be there. Nobody else can do them.
Link one: recognise it and call
Somebody has to look at a person who is grey, limp and gasping and conclude, within seconds, that this is a cardiac arrest. This is where most of the lost time in real cases accumulates — the pause of disbelief, the search for a pulse, the phone call to a relative before 112. It is also the link most improved by information rather than equipment, which is the whole reason this surface exists.
Link two: CPR now, not perfect CPR later
Chest compressions started by a bystander roughly double to triple the chance of survival, and the effect is largest in the first minutes. Bystander CPR rates vary enormously between countries in this region, from well under a third of arrests in some places to the great majority in the Nordic systems with mature dispatcher-CPR and volunteer-responder programmes — a difference in behaviour, not in medicine.
Link three: a shock in the first minutes
For a shockable rhythm, defibrillation is the treatment and everything else is a holding action. The often-quoted figure is that the chance of survival falls by roughly ten percentage points for every minute between collapse and shock, and that good CPR flattens that curve considerably. That single number explains everything about public-access defibrillation: an ambulance responding in eight to fifteen minutes cannot deliver it, so a device in a cabinet a hundred metres away has to.
Links four and five: the hospital and afterwards
Advanced life support, coronary intervention, temperature management and intensive care make up the fourth link, and the fifth — recovery — was added in recognition that surviving is not the end of the story. Survivors and their families face cognitive, emotional and cardiac consequences for months, and follow-up and rehabilitation are now treated as part of the chain rather than an afterthought. Bystanders who performed CPR are part of that picture too, and debriefing them is standard good practice in several systems in this region.
| Link | Who does it | Time window | What it buys |
|---|---|---|---|
| Early recognition and call | Whoever is there | Seconds | Starts everything else |
| Early CPR | Bystander, dispatcher-coached | Immediately | Roughly doubles to triples survival |
| Early defibrillation | Bystander or responder with an AED | First minutes | The definitive treatment for a shockable rhythm |
| Advanced life support | Ambulance crew, hospital | On arrival | Airway, drugs, cause-directed treatment |
| Recovery | Hospital, rehabilitation, family | Weeks to months | Function, not just a pulse |
Sources: European Resuscitation Council Guidelines · International Liaison Committee on Resuscitation (ILCOR) · checked 2026-09-08
Frequently asked questions
Which link matters most?
The one that is missing. In practice the first three fail most often, and they are the ones no professional can supply — recognition, compressions and a defibrillator all have to come from whoever is standing there.
Does bystander CPR really change survival that much?
Yes. Bystander compressions are consistently associated with roughly two to three times the survival of no bystander CPR, and the effect is largest in the first minutes after collapse.
Why is recovery counted as a link?
Because surviving with severe cognitive or emotional consequences is a different outcome from surviving well. Follow-up, rehabilitation and support for the family and for the rescuers are now treated as part of the chain.
How the system around it works
What the survival numbers actually say
Roughly one in ten survives an out-of-hospital cardiac arrest, and the spread between towns is wider than the spread between treatments. How to read the statistics without being misled by them.
National registers, and getting your device into one
A defibrillator the dispatcher cannot see barely exists. What a national register is, which one is the real one in each country, why registration is free, and the paid look-alikes to avoid.
Volunteer responder systems
Denmark, Sweden and Norway alert trained volunteers by phone to arrests near them — one to fetch the defibrillator, one to start compressions. How the systems work, who can join, and what happens when your phone goes off.
Where public defibrillators actually are
The green sign with the heart and the lightning bolt, the places that reliably have one, the cabinets that are locked and the ones that are not, and what to do when you have thirty seconds to decide whether to go looking.
What a defibrillator costs to buy and to keep
The purchase is the small part. Pads and batteries expire on a schedule, cabinets and signage cost real money in a cold climate, and the recurring line is what an organisation forgets to budget for.
Everything on this subject
Before the emergency, there is a long quiet stretch
Blood pressure, resting heart rate, movement and sleep are the part of this you can act on for years beforehand. TempoLife keeps them in one place, free to start.