What should responders do if an adult becomes unresponsive and is not breathing?

When an adult becomes unresponsive and is not breathing, the most critical action to take is to begin CPR and call for emergency medical help immediately. This response is essential because the lack of breathing indicates that the person's heart may not be effectively pumping blood, leading to potential brain damage or death if not addressed rapidly.

Initiating CPR involves chest compressions that help maintain blood circulation to vital organs, particularly the brain and heart, until professional medical help arrives. The combination of calling for emergency medical assistance while starting CPR ensures that advanced medical care is on its way as you provide necessary lifesaving interventions.

In this situation, waiting for assistance, checking the pulse for 10 seconds, or administering rescue breaths alone are inadequate responses. Each of these actions delays critical lifesaving treatment and increases the risk of serious complications for the unresponsive individual. Therefore, starting CPR without delay and summoning emergency services is the proper course of action.