Which value represents the normal arterial oxygen tension (PaO2) range?

Which value represents the normal arterial oxygen tension (PaO2) range?

• A. 60-80 mmHg
• B. 80-100 mmHg
• C. 100-120 mmHg
• D. 40-60 mmHg

Answer: (B)

PaO2 represents the amount of oxygen dissolved in arterial blood, a key measure when assessing how well oxygen is moving from the lungs into the bloodstream. In healthy adults at sea level, the normal range for PaO2 is about 80 to 100 mmHg. This range reflects adequate dissolved oxygen available for tissues after diffusion from the lungs. If PaO2 falls below 80 mmHg, it indicates hypoxemia and impaired gas exchange. Values in the 60–80 mmHg zone suggest mild to moderate hypoxemia, while 40–60 mmHg signals more severe hypoxemia. A PaO2 in the 100–120 mmHg range is typically due to supplemental oxygen or hyperoxia and is not considered a baseline normal value.

PaO2 represents the amount of oxygen dissolved in arterial blood, a key measure when assessing how well oxygen is moving from the lungs into the bloodstream. In healthy adults at sea level, the normal range for PaO2 is about 80 to 100 mmHg. This range reflects adequate dissolved oxygen available for tissues after diffusion from the lungs.

If PaO2 falls below 80 mmHg, it indicates hypoxemia and impaired gas exchange. Values in the 60–80 mmHg zone suggest mild to moderate hypoxemia, while 40–60 mmHg signals more severe hypoxemia. A PaO2 in the 100–120 mmHg range is typically due to supplemental oxygen or hyperoxia and is not considered a baseline normal value.