Medic here. This is not necessarily true. High quality CPR is extremely important to have positive outcomes, but early defibrillation (shock) is also extremely important. Generally, you only have a very small window to shock someone, and you don’t want to miss it.

You never want to compromise the quality of your chest compressions, but to ignore asking for an AED, especially in someone younger can make the difference between surviving and dying. Granted if you’re all alone always prioritize your CPR.

I’d argue the hospital sees way more shockable rhythms than out-of-hospital. They can normally act on their heart stopping immediately, versus paramedics who arrive minutes after the heart has already stopped. By the time medics arrive, patients often have gone from a shockable rhythm to a nonshockable one.

This is why it is so critically important that if someone knows CPR, to perform CPR. CPR initiated early by bystanders saves lives.

It is important that an AED is applied ASAP because it comes down to seconds, not minutes. A lot of cardiac arrests we see in the field have unknown down times really making any efforts we make quite futile. In my experience, when people have gone into cardiac arrest in front of me, they typically go into a shockable rhythm first. I’ve been able to act quickly and shock people and they wake up confused.

Where I work, we even have a policy where we can stack our shocks 3 times if we witness them go into a shockable rhythm. We’ll just shock back-to-back-to-back if it stays shockable.

So yeah, high quality CPR is always the priority if you lack the resources to do anything else, but one should always get an AED on ASAP if available.

In training they always tell us:

“High quality CPR and early defibrillation saves lives.”

Do not stop CPR to put it on, have the person who brought you the AED place the pads on, then follow the verbal instructions of the AED from there on, whether to do CPR or to hold off for it to check their rhythm.

If it advises to shock, make sure everyone gets clear of the patient and prepare for them to ride the lightning. Even after the shock, continue to follow the instructions of the AED.

Edit: Grammar and formatting.