Call emergency services on speakerphone, then begin CPR immediately if the child is unresponsive and not breathing normally. If you are alone, do not leave to find help or an AED first. Start chest compressions at 100 to 120 per minute, push at least one-third the depth of the chest, and continue until responders arrive or the child shows clear signs of life.
The Physiology of Collapse
Sudden collapse in a child usually means the brain has lost adequate blood flow, either because the heart stopped pumping effectively or because its electrical rhythm became chaotic. Within 10 to 20 seconds of circulatory arrest, consciousness fades. Without chest compressions, irreversible brain injury can begin within 4 to 6 minutes at normal body temperature.
Children rarely collapse from the same causes as adults. In adults, the dominant mechanism is ventricular fibrillation, a chaotic quivering of the heart muscle. In children, collapse more often follows respiratory failure or shock that starves the heart of oxygen first. The heart slows, then stops. This matters because oxygen delivery and ventilation carry more weight in pediatric resuscitation than in adult resuscitation.
When you push on a child's chest, you are not restarting the heart directly. You are generating a pressure gradient that moves oxygenated blood to the brain and coronary arteries. Compressions create the circulation that keeps brain tissue viable until a defibrillator or medications can correct the underlying rhythm. Every second without compressions is a second the brain loses oxygen.
How Fast Brain Injury Progresses
Survival falls steeply with each minute without CPR. For every minute that passes without chest compressions in out-of-hospital cardiac arrest, survival drops by roughly 7 to 10 percent in general adult data, and the decline is at least as steep in children. Bystander CPR roughly doubles or triples survival odds compared with no bystander action.
The numbers that matter most are practical. Chest compressions should begin within 1 minute of collapse if possible. Compression rate should stay between 100 and 120 per minute. Depth should be at least one-third of the chest's front-to-back diameter, roughly 1.5 inches (4 cm) in infants and about 2 inches (5 cm) in children. Allow the chest to recoil fully between compressions.
Defibrillation matters when the rhythm is shockable, but in children the shockable rhythm is less common than in adults. Still, if an automated external defibrillator is within reach and someone else is present, it should be applied without interrupting compressions for more than a few seconds. When you are alone, the priority is compressions and a phone call, not a search for a device.
What the Timeline Looks Like
| Time after collapse | What is happening | Immediate action |
|---|---|---|
| 0 to 10 seconds | Consciousness fades; breathing may be gasping or absent | Check responsiveness and breathing; call emergency services |
| 10 to 30 seconds | Circulation to brain drops sharply | Start chest compressions |
| 1 to 4 minutes | Brain cells begin losing viability without oxygen | Continue compressions; keep phone on speaker |
| 4 to 6 minutes | Risk of irreversible brain injury rises | Maintain 100 to 120 compressions per minute |
| 6 to 10 minutes | Survival odds fall substantially without CPR | Continue until responders or AED arrives |
| 10 minutes and beyond | Survival without CPR becomes unlikely | Do not stop compressions unless the child revives |
This timeline is general. A child submerged in cold water, for example, may tolerate longer downtime because hypothermia slows metabolism. A child with a witnessed collapse and immediate CPR has the best odds. The table shows why the first minute is the single most valuable minute you have.
Edge Cases That Change the Playbook
Not every collapse is cardiac arrest. A child who faints from a temporary drop in blood pressure usually regains consciousness within seconds to a minute and begins breathing normally. A child having a seizure may be unresponsive and jerking, but the heart is still beating. A child choking may be conscious but unable to breathe or speak.
The distinction matters because CPR on a child with a beating heart can cause harm. Check for normal breathing before starting compressions. Gasping is not normal breathing and should be treated as cardiac arrest. If the child is breathing normally but unresponsive, place them on their side and monitor until help arrives.
One counterintuitive professional caveat: compressions delivered to a child who is not in cardiac arrest carry real risk, but delaying compressions on a child who is in arrest carries far greater risk. When in doubt and the child is unresponsive with no normal breathing, start compressions. Emergency dispatchers are trained to coach you through this distinction in real time, which is another reason to call first and put the phone on speaker.
Another edge case is the child who collapses and then vomits. Roll the child onto their side briefly to clear the airway, then resume compressions. Do not spend more than a few seconds on this.
Common Misconceptions
A frequent mistake is leaving the child to search for help or an AED. When you are alone, leaving the child costs minutes of no circulation. Calling from a speakerphone beside the child keeps you with them and gets professional guidance simultaneously.
Another misconception is that rescue breaths are always required. For an untrained or hesitant bystander, compression-only CPR is far better than nothing. Hands-only CPR has been shown to be effective for out-of-hospital cardiac arrest and is easier to perform under stress. If you are trained and willing, add rescue breaths at a ratio of 30 compressions to 2 breaths. If not, keep pushing.
People also assume a child who is gasping is breathing. Gasping is a reflexive sign of severe oxygen deprivation, not effective breathing. Treat gasping as cardiac arrest and start compressions.
A final misconception is that CPR always restarts the heart. In reality, CPR buys time. The heart often needs a defibrillator or medications to restore a normal rhythm. Your job is to keep blood flowing until those tools arrive.
Practical Actions, Step by Step
Check responsiveness: tap the child and shout. If no response, check breathing for no more than 10 seconds. Call emergency services immediately on speakerphone. Give the location, the child's age, and that the child is unresponsive. If the child is not breathing normally, start chest compressions. Place the heel of one hand (or two hands for a larger child) on the lower half of the breastbone. Push hard and fast: 100 to 120 compressions per minute, at least one-third the depth of the chest. Let the chest fully recoil. Continue without stopping until the child breathes normally, moves purposefully, or responders take over. If a second person arrives, have them find an AED and follow its voice prompts.
For infants under 1 year, use two fingers on the breastbone if you are alone, or two thumbs encircling the chest if a second rescuer is present. For children 1 year and older, one or two hands work depending on the child's size. The compression rate and depth targets stay the same.
If the collapse was a choking event and the child becomes unresponsive, begin CPR and check the mouth for a visible object before giving breaths. Do not perform blind finger sweeps.
Limits of Bystander Action
Bystander CPR is not a guarantee. Survival depends on the cause of collapse, how quickly compressions start, and whether a shockable rhythm is present. Even perfect bystander CPR cannot reverse every arrest. Research consistently shows that early compressions improve outcomes, but outcomes still vary widely by circumstance.
You also cannot reliably diagnose the cause of collapse in the moment. That is not your job. Your job is to call for help, start compressions when the child is unresponsive and not breathing normally, and keep going. Dispatchers and responders handle the diagnosis.
Physical limits are real. Compressions are exhausting. If another person is available, switch every 2 minutes to maintain depth and rate. If you are alone, keep going as long as you can and do not stop to rest.
For medical emergencies like a child's sudden collapse, this article is general educational information, not a diagnosis, treatment plan, or substitute for professional guidance. It does not promise any outcome. Call your local emergency number immediately and follow the instructions of dispatchers and qualified clinicians.