What is the recommended action for a lone rescuer performing CPR on an adult?

The recommended action for a lone rescuer performing CPR on an adult is to perform compressions followed by ventilations at a 30:2 ratio. This approach prioritizes high-quality chest compressions, which are fundamental to maintaining circulation and delivering oxygen to vital organs during cardiac arrest.

The 30:2 compression-to-ventilation ratio means that the rescuer should deliver 30 chest compressions followed by 2 rescue breaths. This method ensures consistent blood flow and supports oxygenation, optimizing the chances of survival until advanced medical help arrives.

In contrast, strategies that would involve delivering breaths for over 2 seconds or switching to rescue breathing after 10 cycles do not align with the guidelines, as they can interrupt the rhythm of compressions and delay critical circulatory support. Additionally, keeping the airway closed while giving breaths is not appropriate in this context, as it prevents effective delivery of air into the lungs. Thus, the 30:2 ratio effectively balances the need for compressions and ventilations in adult CPR by maximizing circulation while supporting breathing.