It is called CCR (Cardiocerebral resuscitation, or continuous compression resuscitation, or hands only cpr). It is Cpr without pausing to breath. Of the 30 compressions you are suposed to do during normal CPR before you stop for breaths, like 25 of those compressions are just getting the BP high enough to perfuse the brain, then you stop for breaths and start all over. CCR not only keeps that BP up, but you provide supplemental oxygen and a simple airway device, like an opa. It moves enough air to fill the lungs enough to oxygenate what little blood is being circulated.

It is becoming standard protocol for paramedics to do the first 3 rounds (6 minutes) of CPR as CCR as long as the arrest wasn't airway related (drowning, choking, etc). Not only is it associated with better outcomes clinically, but in the field with limited providers on scene it frees up hands to allow for medication administration and rhythm analysis/treatment.