How much force should be applied during chest compressions for infants?

The appropriate amount of force applied during chest compressions for infants is to ensure that the compressions are effective while also minimizing the risk of injury. The correct answer emphasizes that compressions should be at least one-third the anteroposterior (AP) diameter of the chest. This measurement is crucial because it ensures that the compressions are deep enough to generate adequate blood flow during cardiac arrest, while still being mindful of the infant's smaller size and fragility.

By compressing at least one-third the chest's depth, the compressions can create sufficient pressure to circulate blood effectively. This depth translates to about 1.5 inches (4 cm) for infants. If compressions are not deep enough, as would occur with light pressure or moderate pressure, there is a risk that they won't be effective in generating blood circulation, which can critically impact the infant's chances of survival during a cardiac event. Therefore, the recommendation of achieving at least one-third the AP diameter highlights the balance between effectiveness and safety in performing infant CPR.