| | Public Health & Safety | CPR What is compression-ventilation ratio for 1 rescuer adult CPR? The compression-ventilation ratio for 1 rescuer adult CPR is 30:2. This means that for every 30 chest compressions, 2 rescue breaths should be given. CPR - Related Articles Where does the CPR run? Can you get arrested for trying to commit suicide? How to Get Certified in Infant and Child CPR CPT code for group counseling under evaluation and management? How to Give an Adult CPR How does CPR work? Can any person perform CPR without taking classes or learning how?