During CPR for an average adult, how deep should chest compressions be performed to ensure effectiveness?

During CPR for an average adult, how deep should chest compressions be performed to ensure effectiveness?

• A. 1 inch (2.5 cm)
• B. 2 inches (5 cm)
• C. 3 inches (7.5 cm)
• D. 4 inches (10 cm)

Answer: (B)

The key idea is delivering enough chest compression depth to push blood out of the heart while keeping the chest able to fully recoil. For an average adult, target about 2 inches (5 cm), which is roughly one‑third of the chest’s depth. This depth provides sufficient pressure to promote blood flow without causing excessive injury. Compressing only about 1 inch tends to yield poor blood flow, while going much deeper (around 3 inches or more) increases the risk of rib or internal injuries and can hinder effective chest recoil and perfusion.

The key idea is delivering enough chest compression depth to push blood out of the heart while keeping the chest able to fully recoil. For an average adult, target about 2 inches (5 cm), which is roughly one‑third of the chest’s depth. This depth provides sufficient pressure to promote blood flow without causing excessive injury. Compressing only about 1 inch tends to yield poor blood flow, while going much deeper (around 3 inches or more) increases the risk of rib or internal injuries and can hinder effective chest recoil and perfusion.