A PaO2 of 75 mm Hg indicates which condition?

A PaO2 of 75 mm Hg indicates which condition?

• A. Hypoxemia
• B. Normoxemia
• C. Hyperoxemia
• D. Hyperoxia

Answer: (A)

PaO2 measures the amount of oxygen dissolved in arterial blood. Normal is about 80–100 mm Hg; when PaO2 drops below 80, it means there is not enough oxygen in the blood entering the tissues—hypoxemia. A value of 75 mm Hg is slightly below normal, indicating mild hypoxemia that can arise from issues like ventilation challenges, diffusion problems, or ventilation–perfusion mismatch. Hyperoxemia or hyperoxia would involve PaO2 values above the normal range, which isn’t the case here.

PaO2 measures the amount of oxygen dissolved in arterial blood. Normal is about 80–100 mm Hg; when PaO2 drops below 80, it means there is not enough oxygen in the blood entering the tissues—hypoxemia. A value of 75 mm Hg is slightly below normal, indicating mild hypoxemia that can arise from issues like ventilation challenges, diffusion problems, or ventilation–perfusion mismatch. Hyperoxemia or hyperoxia would involve PaO2 values above the normal range, which isn’t the case here.