Oxygenation Index (OI/OSI)

Name: Oxygenation Index (OI/OSI)
Creator: Daniel Diaz-Gil, MD
Keywords: oxygenation index, OI, OSI, FiO2, MAP, PaO2, SpO2, ECMO, ARDS, ventilator, pulmonology, pediatric

Calculates Oxygenation Index and Oxygen Saturation Index for assessing severity of hypoxemic respiratory failure

Clinically Verified· 6 tests

For educational and informational purposes only. Verify all results before clinical application.

FiO2 (%) *

Mean Airway Pressure (cmH2O) *

cmH₂O

PaO2 (mmHg) *

mmHg

SpO2 (%)

Pulse oximetry SpO2 (%). OSI uses SpO2 instead of PaO2. Only valid when SpO2 ≤ 97% (above this, the SpO2-PaO2 relationship is non-linear).

References

Thomas NJ, Shaffer ML, Willson DF, et al. Defining acute lung disease in children with the oxygenation saturation index. Pediatr Crit Care Med. 2010;11(1):12-17.[DOI]

Reviewed by Daniel Diaz-Gil, MD · Last updated March 2026

Medical disclaimer

This tool is for educational and informational purposes only. It is not a substitute for professional clinical judgment. Always independently verify results before making clinical decisions.

Professional Resources — Tools used by pediatricians for respiratory assessment

Kendig's Disorders of the Respiratory Tract in ChildrenComprehensive pediatric pulmonology reference~$180via Amazon Pediatric Pulse OximeterFingertip pulse oximeter suitable for pediatric patients~$30via Amazon