Oxygenation Index (OI) Calculator
Calculate Oxygenation Index for pediatric and neonatal ICU patients. Assess severity of hypoxic respiratory failure and determine ECMO eligibility criteria.
About
The Oxygenation Index (OI) is a standard physiological calculation used in Intensive Care Units to measure the efficiency of oxygen exchange in the lungs. Unlike the P/F ratio, the OI incorporates Mean Airway Pressure (MAP), making it a superior metric for patients on positive pressure ventilation, particularly neonates and children with acute respiratory distress syndrome (ARDS).
High OI values indicate severe resistance to oxygenation therapy. Clinicians monitor this trend meticulously. An escalating OI despite maximized ventilator settings serves as the primary trigger for escalating to high-frequency oscillatory ventilation (HFOV) or Extracorporeal Membrane Oxygenation (ECMO). Immediate calculation accuracy is vital for these life-support decisions.
Formulas
The formula normalizes the pressure required to achieve oxygenation against the actual arterial oxygen level.
Where:
MAP = Mean Airway Pressure (cmH2O)
FiO2 = Fraction of Inspired Oxygen (0.21 to 1.0)
PaO2 = Partial Pressure of Oxygen (mmHg)
Reference Data
| Oxygenation Index (OI) | Severity Category | Clinical Action / Consideration | Mortality Risk (Est.) |
|---|---|---|---|
| 0 − 15 | Mild / Normal | Standard Ventilation | < 10% |
| 15 − 25 | Moderate Hypoxia | Consider HFOV / Nitric Oxide | 15% − 30% |
| 25 − 40 | Severe Hypoxia | High Mortality Risk. HFOV indicated. | > 40% |
| > 40 | Critical Failure | ECMO Candidacy Criteria | > 80% (w/o ECMO) |