Oxygen Index (OI)

Oxygen Index

Oxygenation Index = (FiO2 * Mean Airway Pressure) / PaO2
The oxygenation index is used to assess the intensity of ventilatory support required to maintain oxygenation. It is used in neonates / pediatrics to assess the need for potential ECMO therapy.

Fraction of inspired oxygen (FiO2) in %:
Mean airway pressure (MAP) in mmHg:
Partial pressure of oxygen (PaO2) in mmHg:
Oxygenation Index (OI)

0-25 index : Good outcome
25-40 index : Chance of death > 40%
30-1000 index : > 4 hours – Increased risk of worsening / death
40-1000 index : Consider ECMO (extracorporeal membrance oxygenation)

Download RespCalc Respiratory Calculator Premium Medical App for iPhone. Download RespCalc Respiratory Calculator form Google Play.



M Van Haperen . “The Oxygenation Index compared with the P/F ratio in ALI/ARDS”. Critical Care.
http://ccforum.com/content/16/S1/P91 (30 May, 2012)

Brudno DS, Boedy RF, Kanto WP Jr. Compliance, alveolar-arterial oxygen difference, and oxygenation index changes in patients managed with extracorporeal membrane oxygenation. Pediatric Pulmonology 1990; 9(1): 19–23 . PubMed PMID: 2388774.


By clicking on the “Calculate” button, you acknowledge that you have read, understand, and agree to be bound by the terms of the RespCalc Online Calculator End User Agreement.

Speak Your Mind