CaO2 calculation: Hb = 15 g/dL, SaO2 = 97%, PaO2 = 80 mmHg. What is CaO2?

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CaO2 calculation: Hb = 15 g/dL, SaO2 = 97%, PaO2 = 80 mmHg. What is CaO2?

CaO2 shows how much O2 is carried in blood, from two sources: oxygen bound to hemoglobin and dissolved oxygen in plasma. Use CaO2 = (Hb × 1.34 × SaO2) + (PaO2 × 0.003). Plug in the values: Hb = 15 g/dL, SaO2 = 97% = 0.97, PaO2 = 80 mmHg. Bound O2 = 15 × 1.34 × 0.97 ≈ 19.5 mL/dL. Dissolved O2 = 80 × 0.003 = 0.24 mL/dL. Total CaO2 ≈ 19.5 + 0.24 ≈ 19.7 mL/dL. The dissolved portion is small; the CaO2 is dominated by the oxygen bound to hemoglobin, giving about 19.7 mL/dL.

CaO2 shows how much O2 is carried in blood, from two sources: oxygen bound to hemoglobin and dissolved oxygen in plasma. Use CaO2 = (Hb × 1.34 × SaO2) + (PaO2 × 0.003).

Plug in the values: Hb = 15 g/dL, SaO2 = 97% = 0.97, PaO2 = 80 mmHg.

Bound O2 = 15 × 1.34 × 0.97 ≈ 19.5 mL/dL.

Dissolved O2 = 80 × 0.003 = 0.24 mL/dL.

Total CaO2 ≈ 19.5 + 0.24 ≈ 19.7 mL/dL.

The dissolved portion is small; the CaO2 is dominated by the oxygen bound to hemoglobin, giving about 19.7 mL/dL.

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