When responding to a suspected cardiac arrest, what is the immediate priority?

In the context of a suspected cardiac arrest, the immediate priority is to start CPR (cardiopulmonary resuscitation) as quickly as possible. This is crucial because the heart has stopped pumping blood, which means that vital organs, especially the brain, are not receiving oxygen. Each minute without adequate blood flow significantly increases the risk of irreversible damage or death.

Initiating CPR helps to maintain some level of blood circulation, which can be life-saving and can preserve brain function until advanced medical help arrives. CPR combines chest compressions and, if trained, rescue breaths to restore circulation and oxygenation to the body's tissues.

While applying an AED quickly after initiating CPR is essential, it is secondary to the immediate action of starting chest compressions. Checking for a pulse for an extended duration, such as one minute, would delay life-saving interventions, as would simply administering high-flow oxygen without immediate chest compressions. Time is of the essence during a cardiac arrest, making immediate CPR the critical first action.