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🩸 Arterial Oxygen Content (CaO₂)

Calculate arterial oxygen content (CaO₂) carried per 100 mL of blood.

Arterial Oxygen Content (CaO₂)

Haemoglobin (g/dL)
SaO₂ (%)
PaO₂ (mmHg)

When to use

Quantify oxygen content for delivery and shunt calculations.

How it works

CaO₂ = 1.34 × Hb × SaO₂ + 0.0031 × PaO₂. Normal ≈ 18–20 mL O₂/dL.

Key points

  • Most oxygen is bound to haemoglobin; dissolved O₂ is small.
  • Anaemia lowers content despite a normal SaO₂.
  • Feeds into DO₂ and oxygen extraction calculations.

References

Decision support for licensed clinicians only; not a substitute for clinical judgement, diagnosis or local protocols.

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