When a patient has hypoxemia and supplemental oxygen is started, what is the next essential assessment?

• A. Cardiac enzymes.
• B. Airway patency and breathing status.
• C. Nutritional intake.
• D. Skin integrity.

Answer: (B)

Ensuring airway patency and adequate breathing is the immediate priority after starting oxygen. Oxygen therapy can only improve oxygenation if air can reach the lungs and ventilation is effective. So the next essential assessment is to check that the airway is open and the patient is ventilating properly: assess airway patency, observe breathing rate and effort, listen to breath sounds, look for signs of obstruction or distress, monitor chest rise, color, and SpO2. If any issues are found, intervene right away—position the head, clear secretions, suction, insert an airway adjunct if needed, and be prepared to assist or escalate to bag‑valve‑mask ventilation or advanced airway support. Only once airway and ventilation are confirmed should you evaluate the response to oxygen and continue monitoring.

Briefly, the other options don't address the immediate need: cardiac enzymes help diagnose cardiac injury but aren’t the next step in optimizing oxygenation; nutritional intake and skin integrity are long-term concerns and not part of the urgent assessment after starting oxygen.