Final answer:
If a patient is unconscious but breathing with a good pulse, the next step is to assess their airway, breathing, and circulation.
Step-by-step explanation:
If a patient is discovered unconscious and is breathing with a good pulse, the next step would be to assess their ABCs - Airway, Breathing, and Circulation. The airway should be checked to ensure it is clear and there are no obstructions that could hinder breathing. Breathing should be monitored closely to ensure it remains adequate. Circulation should be assessed by checking the patient's pulse and blood pressure.