After establishing that an adult patient is unresponsive, what should you do first?

In the scenario of an unresponsive adult patient, the first action to take is to open the airway. This is crucial because if the person's airway is obstructed, it can prevent any air from entering the lungs, leading to inadequate oxygenation regardless of whether they are breathing or have a pulse. By ensuring that the airway is clear, you create the best possible conditions for effective ventilation, which is vital for the patient’s survival.

Once the airway is open, it is appropriate to then assess for breathing. This step is critical as it informs the responder whether the patient is breathing spontaneously or requires assistance.

Checking for a pulse is also significant, but it should follow establishing the airway and assessing breathing. The reason for this sequence is grounded in the principles of immediate life support; without an airway or breath, a pulse is irrelevant since there’s no circulation of oxygen-rich blood occurring.

While attaching an automated external defibrillator (AED) is an important step in cases of cardiac arrest, it comes after the initial management of the airway and assessment of breathing. Implementing CPR and using an AED are vital components in certain situations, but airway management takes precedence to ensure that oxygen delivery is optimized before any further intervention.