How does full sternum recoil benefit the cardiovascular system during CPR?

Full sternum recoil during CPR is vital as it promotes effective venous return. When chest compressions are administered, the heart is compressed, which helps pump blood out into circulation. However, once the pressure is released and the sternum fully recoils, it creates a negative pressure within the thoracic cavity. This negative pressure allows blood to flow back into the heart, specifically into the right atrium, enhancing venous return.

Effective venous return is crucial for maintaining adequate blood flow and oxygen delivery to vital organs during cardiac arrest. If the chest does not fully recoil, it could impede the return of blood to the heart, reducing the volume of blood available for the next cycle of compressions and ultimately diminishing the effectiveness of CPR.

In contrast, while increasing blood pressure and stabilizing electrical impulses are important aspects of overall cardiovascular function, they are secondary outcomes that depend on the efficiency of the compressions and the subsequent filling of the heart dictated by good sternum recoil. Reducing oxygen consumption is also not directly enhanced by sternum recoil; rather, the overall effectiveness of CPR can help improve oxygen delivery during re-establishment of circulation.