CPR compression depth and rate

Your heart is a pump. Every beat sends blood to your brain and body, carrying the oxygen they need.

In cardiac arrest the heart stops pumping. Blood stops, and the brain gets no oxygen. Damage can start in four minutes.

Now you are the pump. The heart sits between breastbone and spine. Each push squeezes blood out; each rise lets it refill.

Adult compressions go two to two point four inches deep. That’s the green band.

Watch a tired rescuer. After a minute and a half to two minutes, depth starts to slip. Too shallow, and less blood moves.

Push hard. Every compression lands in the band. With a partner, switch compressors about every two minutes. That is about when tired hands start to slip.

Push fast: one hundred to one twenty compressions a minute. Keep pauses short. When you stop, the pressure you built drops almost at once.

Thirty compressions, then two breaths. That is the adult cycle, alone or with a partner, until an advanced airway is in.

One rescuer, adult patient. What is the compression-to-breath ratio?

1. 15 : 2
2. 30 : 2
3. 5 : 1

Answer: 30 : 2. 30 : 2 for any adult without an advanced airway, one rescuer or two. Once an advanced airway is in, compressions go nonstop with one breath every 6 seconds.

Let the chest come all the way back up every time. Leaning on it keeps the heart from refilling fully.

Next lesson: General impression from the doorway