What is the recommended CPR compression-to-ventilation ratio for an adult when two rescuers are present?

• A. 15 compressions to 2 breaths; switch every minute.
• B. 20 compressions to 1 breath; switch every 90 seconds.
• C. 30 compressions to 2 breaths; switch rescuers about every 2 minutes.
• D. 30 compressions to 2 breaths; never switch.

Answer: (C)

When two rescuers are giving adult CPR, the goal is to keep blood flowing effectively while providing just enough breaths without breaking the rhythm. The recommended cycle is thirty chest compressions followed by two breaths, repeated. Switching roles about every two minutes helps maintain the quality of compressions, since fatigue can cause depth and rate to drop. This balance keeps circulation strong and ensures ventilation continues at a steady pace. Other patterns would disrupt this rhythm, and not switching at all lets fatigue quickly reduce effectiveness. So, the best approach is thirty compressions to two breaths, with rescuers swapping roughly every two minutes.