What PaO2 value is generally considered adequate oxygenation for a healthy adult?

What PaO2 value is generally considered adequate oxygenation for a healthy adult?

• A. PaO2 80–100 mmHg; SaO2 typically ≥ 95%.
• B. PaO2 60–80 mmHg; SaO2 90–92%.
• C. PaO2 120–140 mmHg; SaO2 ≥ 99%.
• D. PaO2 40–60 mmHg; SaO2 75–85%.

Answer: (A)

Normal oxygenation means the arterial oxygen tension is in the typical healthy range and hemoglobin is nearly fully saturated. For a healthy adult breathing room air, PaO2 is about 80–100 mmHg and SaO2 is roughly 95–100%. This makes the scenario with PaO2 in the 80–100 range and SaO2 at or above 95% the best match for adequate oxygenation. Values lower than that, such as 60–80 mmHg with SaO2 around 90–92%, indicate mild hypoxemia and aren’t considered fully adequate. Values higher, like 120–140 mmHg with SaO2 ≈ 99%, reflect hyperoxia and aren’t needed in a healthy person. Values far lower, such as 40–60 mmHg with SaO2 75–85%, show significant hypoxemia.

Normal oxygenation means the arterial oxygen tension is in the typical healthy range and hemoglobin is nearly fully saturated. For a healthy adult breathing room air, PaO2 is about 80–100 mmHg and SaO2 is roughly 95–100%. This makes the scenario with PaO2 in the 80–100 range and SaO2 at or above 95% the best match for adequate oxygenation.

Values lower than that, such as 60–80 mmHg with SaO2 around 90–92%, indicate mild hypoxemia and aren’t considered fully adequate. Values higher, like 120–140 mmHg with SaO2 ≈ 99%, reflect hyperoxia and aren’t needed in a healthy person. Values far lower, such as 40–60 mmHg with SaO2 75–85%, show significant hypoxemia.