Rescuers should immediately resume CPR with chest compressions if what occurs?

Rescuers should immediately resume CPR with chest compressions when no shock is needed. This occurs during the assessment phase after the defibrillator has analyzed the heart rhythm and determined that the rhythm is not shockable, such as in cases of asystole or pulseless electrical activity (PEA). In these situations, the most critical action is to return to high-quality chest compressions because they help maintain vital blood flow to the brain and other organs until advanced medical care can be provided or until the rhythm changes to a shockable one.

In contrast, when a shock is advised, rescuers must first deliver the shock before resuming CPR. If the AED malfunctions or the victim begins to breathe, it would indicate a different set of immediate actions rather than a direct return to compressions without first assessing those conditions. However, the paramount focus in cases of non-shockable rhythms is to ensure continuous CPR to optimize the chances of survival for the victim.