A middle-aged man collapses. You and a second rescuer go to the victim and find that he is unresponsive, is not breathing, and does not have a pulse. Which action is most likely to positively impact this victim's survival?

• A. Performing high-quality CPR
• B. Checking for a pulse
• C. Listening for breath sounds
• D. Calling EMS only

Answer: (A)

When an adult is unresponsive with no breathing and no pulse, starting high-quality chest compressions right away is the action most likely to improve survival. Continuous, effective CPR maintains blood flow to the heart and brain until a defibrillator can be used or advanced care arrives. In a two-rescuer scenario, one person can push hard and fast through the chest compressions while the other quickly calls EMS and prepares an AED so a shock can be delivered as soon as possible if indicated.

Delaying CPR to check for a pulse is not reliable—palpating a pulse in an unresponsive adult is often inconclusive and can waste precious time. Listening for breath sounds is also unreliable; many patients in cardiac arrest may have agonal breathing or no effective breathing at all, which can mislead responders. Calling EMS only removes the immediate circulation opportunity; by starting CPR now, you sustain perfusion and improve outcomes while help is on the way. High-quality CPR means compressions at a proper rate and depth with minimal interruptions and full chest recoil, which makes the most difference in survival chances.