The American Red Cross Cardiopulmonary Resuscitation (CPR) Practice Test

Chest compressions for an adult during CPR should be at least 2 inches deep to be effective. This depth is essential because it allows the compressions to create enough pressure to circulate blood and facilitate the return of blood flow to vital organs, particularly the brain and heart. Compressions that are too shallow do not adequately compress the heart, reducing the chances of successful resuscitation.

The guideline of at least 2 inches ensures that the compressions are strong enough to generate adequate blood flow while also adhering to the recommended rate of 100 to 120 compressions per minute. This depth strikes a balance between effectiveness and safety, ensuring that the rescuer can maintain the quality of compressions without risking injury to the victim.