oxygenation_index: Oxygenation Index (OI)

In cliot: Clinical Indices and Outcomes Tools

Oxygenation Index (OI)

Description

Calculates the Oxygenation Index (OI), a dimensionless number used primarily in neonatal and pediatric intensive care to assess the severity of hypoxic respiratory failure. It integrates Mean Airway Pressure (MAP) to quantify the intensity of ventilatory support required to maintain oxygenation. High values correlate with increased mortality and are used as criteria for advanced interventions like HFOV or ECMO.

Usage

oxygenation_index(mean_airway_pressure, fio2_percent, pao2)

Arguments

mean_airway_pressure	Numeric. Mean Airway Pressure (MAP) in cm H2O.
fio2_percent	Numeric. Fraction of Inspired Oxygen as a percentage (e.g., 100 for 100% oxygen).
pao2	Numeric. Partial pressure of arterial oxygen in mmHg.

Details

The formula is:

OI = \frac{FiO_2 (\%) \times MAP}{PaO_2}

Common clinical thresholds:

• OI > 25: High risk, consider HFOV/iNO.

• OI > 40: Very high risk, consider ECMO.

Value

A list containing:

Oxygenation_Index	The calculated OI value.
Interpretation	Clinical guidance based on standard severity thresholds.

References

Ortiz RM, Cilley RE, Bartlett RH. Extracorporeal membrane oxygenation in pediatric respiratory failure. Pediatr Clin North Am. 1987;34(1):39-46. Trachsel D, McCrindle BW, Nakagawa S, Bohn D. Oxygenation index predicts mortality in children with acute hypoxemic respiratory failure. Am J Respir Crit Care Med. 2005;172(2):206-211. doi:10.1164/rccm.200405-625OC

Examples

# Example 1: Severe Failure (ECMO candidate)
# MAP 30, FiO2 100%, PaO2 60
# OI = (100 * 30) / 60 = 50
oxygenation_index(30, 100, 60)

# Example 2: Mild/Moderate
# MAP 15, FiO2 50%, PaO2 80
# OI = (50 * 15) / 80 = 9.38
oxygenation_index(15, 50, 80)

cliot documentation built on Dec. 1, 2025, 1:06 a.m.