If an aircraft oxygen supply fails mid-flight, which sequence of actions is recommended?

• A. Recognize failure, switch to backup oxygen, ensure continued delivery to patient, communicate with crew, and plan for potential emergency landing.
• B. Ignore the alarm and monitor the patient while continuing the flight as planned.
• C. Switch to backup oxygen only after the patient shows signs of hypoxia, and do not notify the crew.
• D. Immediately land at the nearest airport without informing flight control.

Answer: (A)

When oxygen delivery is compromised in flight, the priority is to maintain oxygenation for both the patient and crew while coordinating with the rest of the flight team and preparing for a possible diversion. Start by recognizing the failure—the alarm signals a real hazard that can quickly lead to hypoxia. Then immediately switch to the backup oxygen supply to restore a reliable flow, because the primary system is not delivering adequately. Next, ensure the patient is actually receiving oxygen at the appropriate flow and that the delivery device is functioning and properly fitted, so cerebral and tissue oxygenation are preserved. Communicate with the rest of the crew to keep everyone informed, coordinate any changes in cabin or flight dynamics, and decide on the need for a diversion or emergency landing as conditions warrant. Planning for a potential emergency landing remains a prudent step if oxygen delivery cannot be stabilized or the patient’s condition worsens; this ensures we can reach a safe destination with appropriate medical support.