The Australian Resuscitation Council Guidelines suggest that those who are trained and willing to give rescue breaths do so for all persons in cardiac arrest.

If you’re not trained or are unwilling to give rescue breaths, give chest compressions only. Rescuers should perform chest compressions for all ages at a rate of 100 to 120 compressions per minute (almost 2 compressions/second).

There is some evidence that compression rates less than 100 or greater than 140 compressions per minute are associated with lower rates of survival.