If You Witness a Child Collapse, You Should Do What First?

The answer

The correct response depends on one key detail: did you actually see the child drop?

• Witnessed sudden collapse (you saw the child suddenly fall, is unresponsive and not breathing normally): Call 911 / activate EMS and get an AED first, then start CPR. A sudden witnessed collapse in a child most often means a shockable cardiac rhythm (like ventricular fibrillation), and the single most important treatment for that is rapid defibrillation. Calling first gets the AED and paramedics moving without delay.
• Unwitnessed collapse (you found the child already down, or the arrest is from a respiratory/drowning/choking cause): give 2 minutes (about 5 cycles) of CPR first, then call. Most pediatric arrests are caused by a breathing problem, so restoring oxygen and circulation immediately is the priority when you're alone.

If a second rescuer is present, one person calls and gets the AED while the other starts CPR simultaneously — you never have to choose.

Why the sequence matters

Adult and child arrest patterns differ. Adults usually collapse from a primary cardiac cause, so 'call first / phone first' is the default for them. Children more commonly arrest from hypoxia (asphyxia) — choking, drowning, respiratory illness — where a few minutes of CPR delivers the oxygen the brain and heart are starving for before you step away to phone. The witnessed sudden collapse is the exception that makes a child behave like the adult cardiac case, which is exactly why it flips to call-first.

Whatever the order, once you begin CPR the technique is the same:

• Compression rate: 100–120 per minute.
• Compression depth: about one-third the depth of the chest, roughly 2 inches (5 cm) in a child.
• Compression-to-breath ratio: 30:2 for a single rescuer, 15:2 for two rescuers.
• Allow full chest recoil between compressions and minimize interruptions.

Using an AED on a child

Use an AED as soon as it arrives. For children under 8 or under about 25 kg, use pediatric pads or a pediatric dose attenuator if available; if only adult pads are on hand, use them rather than withhold defibrillation — place one pad on the chest and one on the back if the pads would otherwise overlap. Follow the device's voice prompts, clear everyone before a shock, and resume compressions immediately after.

The bigger picture

The reasoning that ties this together: identify the likely cause. Sudden + witnessed = probable cardiac = get the shock (call first). Found-down or breathing-related = probable hypoxia = restore oxygen first (CPR first). High-quality compressions, early EMS activation, and early defibrillation are the links in the pediatric chain of survival that most improve outcomes.