During chest compressions, compress which fraction of the chest width to allow re-expansion between compressions?

During chest compressions, compress which fraction of the chest width to allow re-expansion between compressions?

• A. 1/2 - 1/3
• B. 1/4
• C. 2/3
• D. 3/4

Answer: (A)

During chest compressions you want enough depth to push blood out of the heart, but you also need the chest to recoil fully between compressions to restore venous return. Compressing to about one-third to one-half of the chest width achieves this balance: it’s deep enough to generate forward flow yet shallow enough to allow complete chest re-expansion. If you go shallower, perfusion drops; if you go deeper than about half the chest width, chest recoil is hindered and venous return suffers. So targeting roughly one-third to one-half of the chest width best supports effective circulation and proper recoil between compressions.

During chest compressions you want enough depth to push blood out of the heart, but you also need the chest to recoil fully between compressions to restore venous return. Compressing to about one-third to one-half of the chest width achieves this balance: it’s deep enough to generate forward flow yet shallow enough to allow complete chest re-expansion. If you go shallower, perfusion drops; if you go deeper than about half the chest width, chest recoil is hindered and venous return suffers. So targeting roughly one-third to one-half of the chest width best supports effective circulation and proper recoil between compressions.