In adult CPR, what is the standard ratio of chest compressions to rescue breaths?

• A. 30:2
• B. 15:2
• C. 30:1
• D. 20:2

Answer: (A)

The main concept is the standard ratio of chest compressions to rescue breaths used in adult CPR. In adults, the recommended rhythm is 30 chest compressions followed by 2 rescue breaths, repeated throughout the resuscitation effort. This 30:2 mix helps sustain blood flow to vital organs while still providing oxygen to the blood, and it minimizes pauses in chest compressions, which is crucial for maintaining perfusion.

The other ratios don’t fit the standard practice for adults. A 15:2 pattern is used for pediatric CPR or when two rescuers are focused on a child, not an average adult. A 30:1 pattern would reduce the time spent delivering breaths and disrupt the balance between circulation and ventilation. A 20:2 pattern isn’t the established guideline for adults and would alter the rhythm away from the proven approach. If an advanced airway is in place, compressions become continuous with breaths delivered at a rate of about one every six seconds, but that’s a different scenario from the standard 30:2.