Which of the following is key point about the correct performance of compressions given during adult CPR?

• A. Release all pressure off the chest between compressions
• B. Ventilate after every 10 compressions
• C. Keep hands on the chest during recoil
• D. Compress to a depth of 6 inches

Answer: (A)

Full chest recoil between compressions is essential. Releasing all pressure off the chest after each compression lets the chest fully rebound, which draws blood back into the heart and prepares it to be pumped again. This full recoil maximizes venous return and improves the effectiveness of each compression. Keeping hands on the chest during recoil prevents this full expansion and reduces blood flow back to the heart. Compressing to a depth of six inches is deeper than recommended for an adult and increases injury risk; the guideline target is about two inches (5 cm). Ventilations are delivered in rhythm with compressions, not after a fixed number like every 10; typically breaths are given in cycle with compressions (for example, 30 compressions followed by 2 breaths).