What is the first-line treatment for suspected in-flight hypoxia?

• A. Administer 100% oxygen and descend to a safer altitude if feasible
• B. Administer 50% oxygen and descend to altitude
• C. Hyperbaric chamber therapy immediately
• D. Observe and monitor without intervention

Answer: (A)

When hypoxia is suspected during flight, the immediate priority is to maximize oxygen delivery and reduce the environmental stress from altitude. Giving 100% oxygen rapidly increases the amount of oxygen available for gas exchange, boosting alveolar and arterial oxygen tensions so the brain and other tissues aren’t starved of oxygen. At the same time, descending to a lower altitude lowers the ambient pressure and improves oxygen availability, making it easier for the lungs to oxygenate blood. This combination directly addresses the root issue and works quickly, which is why it’s the first-line treatment.

Providing only a lower fraction of oxygen would be slower and less effective at reversing hypoxia. Hyperbaric chamber therapy isn’t practical or readily available in-flight settings, and simply observing without intervention allows tissue hypoxia to continue and can worsen outcomes.