When performing CPR for an adult with one or two rescuers, what is the correct ratio of compressions to breaths?

The correct ratio of compressions to breaths when performing CPR on an adult is 30 compressions followed by 2 breaths. This ratio is based on the guidelines established by leading health organizations, which emphasize the importance of maintaining adequate blood circulation through chest compressions while also providing oxygen to the victim.

The reason for this specific ratio—30 compressions to 2 breaths—is to ensure that sufficient blood flow is being generated to vital organs, especially the brain and heart, while also providing necessary ventilation. This method balances the need for chest compressions with the need for oxygenation, aiming to maximize the chances of survival until professional medical help arrives.

In contrast, other ratios are not recommended for adult CPR. For instance, 20 compressions to 1 breath or 15 compressions to 2 breaths are not aligned with current guidelines and would likely reduce the effectiveness of the CPR being administered. The ratio of 30 compressions to 1 breath is also incorrect, as it does not provide the necessary number of breaths relative to the compressions, which could further compromise the oxygen levels during a critical situation. Thus, sticking to the widely accepted 30:2 ratio is essential for effective CPR.