American Board of Internal Medicine (ABIM) Certification Practice Exam

What is the oxygen saturation cutoff at sea level that indicates the need for in-flight supplemental oxygen in COPD patients?

1. 92% or less

2. 90% or less

3. 95% or less

4. 94% or less

The correct answer is: 92% or less

The cutoff for oxygen saturation at sea level that indicates the need for in-flight supplemental oxygen in patients with chronic obstructive pulmonary disease (COPD) is 92% or less. This specific threshold is significant because individuals with COPD often have compromised lung function, which can lead to a reduced capacity for oxygen exchange. At lower saturation levels, particularly below 92%, these patients are at an increased risk for hypoxemia, especially during an airplane's ascent. The environment inside an aircraft can exacerbate breathing issues due to decreased atmospheric pressure, which can further reduce the availability of oxygen. Consequently, maintaining an oxygen saturation level above 92% is crucial for ensuring adequate oxygenation during flight. This threshold helps identify patients who may experience further desaturation due to the altitude changes and necessitates supplemental oxygen to avoid complications such as respiratory distress or worsened hypoxemia. While some other cutoff values may be suggested for specific circumstances, the standard typically acknowledged in clinical practice for determining in-flight oxygen needs in patients with COPD is indeed 92%.