Oxygen Extraction Ratio

The oxygen extraction ratio (O2ER) indicates the fraction of oxygen removed from the blood as it passes through the capillary bed. It reflects the balance between oxygen delivery and consumption.

Disclaimer

This calculator is for educational purposes only. Always verify with clinical judgment.

Calculator

Enter arterial and venous values to calculate CaO2, CvO2, and the extraction ratio.

Hemoglobin (g/dL)

SaO2 (%)

PaO2 (mmHg)

SvO2 (%, mixed venous)

PvO2 (mmHg, mixed venous)

Formula

O2ER = (CaO2 - CvO2) / CaO2 × 100

where CaO2 = (1.34 × Hb × SaO2/100) + (0.003 × PaO2)

References

West JB. Respiratory Physiology: The Essentials, 10th Edition.
Walsh BK. Neonatal and Pediatric Respiratory Care, 5th Edition.