What is the immediate action for suspected in-flight hypoxia when oxygen saturation falls?

• A. Discard the patient from the aircraft.
• B. Administer medication to induce sleep and continue.
• C. Recognize early, administer supplemental oxygen, and descend to a lower altitude as soon as feasible.
• D. Descend to higher altitude to reduce cabin pressure.

Answer: (C)

When hypoxia is suspected during flight, act quickly by recognizing the problem, giving supplemental oxygen, and descending to a lower altitude as soon as feasible. The reason is that at altitude the ambient pressure is reduced, so the amount of oxygen the body can absorb from the air drops. Providing supplemental oxygen increases the fraction of inspired oxygen, helping raise oxygen saturation, but the most effective and fastest improvement comes from descending to a lower altitude where the ambient pressure is higher and oxygen availability improves further. This combination minimizes tissue hypoxia to the brain and heart. Actions like delaying treatment, giving sleep-inducing medication, or climbing to a higher altitude would worsen the situation and are not appropriate.