Cardiac Arrest, CPR, and the AED

1. Recognizing Arrest

The clock starts the second the heart stops. Brain injury begins about 4 to 6 minutes later. By roughly 8 to 10 minutes, it's irreversible. That's why recognition can't drag.

You tap and shout. No response, and you check breathing and pulse at the same time. Watch the chest while you palpate. You get 10 seconds, no more.

No definite pulse in that window means cardiac arrest. You start compressions.

Agonal gasps are not breathing. They're slow, irregular, and ineffective. A patient making those sounds is not ventilating. That gasping is a sign of arrest, not a reason to hold off.

In an infant or child, a pulse under 60 beats per minute with poor perfusion gets treated as arrest too. You don't wait for the pulse to disappear. Slow and poorly perfusing is already the trigger.

Fix the surface before you touch the chest. Compressions only work on something firm and flat under the patient. A patient in a bed, on a couch, or in a chair goes to the floor right now. That's an emergency move, and the position itself is what justifies it — you can't deliver lifesaving care on a mattress.

Adults and kids arrest for different reasons. So it changes what you reach for first. Adult arrest is usually electrical — ventricular fibrillation or pulseless ventricular tachycardia. So the AED is your priority. Pediatric arrest usually follows respiratory failure. The child is already hypoxic by the time the heart stops, so oxygenation carries more weight for a kid than it does for an adult.

There's one exception, and it proves the rule: a previously healthy child who collapses suddenly. That's behaving like an adult arrest. You go straight for the AED.