Compression ratio for Adult CPR with 1 or 2 rescuers?

• A. 30:2
• B. 15:2
• C. 10:2
• D. 40:2

Answer: (A)

The main idea is the standard rhythm used in adult CPR when there are one or two rescuers. For adults, the cycle is 30 chest compressions followed by 2 rescue breaths. This pattern helps maximize blood flow during compressions while providing enough ventilation to supply oxygen to the blood between squeezes. Having a second rescuer can help reduce pauses—one person can resume compressions while the other gives breaths—but the overall sequence remains 30 compressions to 2 breaths. It’s the default approach unless an advanced airway is in place, in which case the method shifts to continuous chest compressions with breaths every about 6 seconds. The other ratios don’t fit adult CPR practice: 15:2 is used for two-rescuer CPR in children, while 10:2 or 40:2 aren’t standard for adults.