Oxygenation Index Calculator For Adults

Oxygenation Index Formula:

\[ OI = \frac{FiO_2 \times MAP}{PaO_2} \times 100 \]

FiO₂ (Fraction of Inspired Oxygen):

unitless (0.21-1.0)

MAP (Mean Airway Pressure):

cmH₂O

PaO₂ (Arterial Oxygen Partial Pressure):

mmHg

Oxygenation Index (OI):

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1. What is the Oxygenation Index?

The Oxygenation Index (OI) is a measure used in critical care medicine to assess the severity of lung injury and the effectiveness of oxygenation. It incorporates both the fraction of inspired oxygen and mean airway pressure in relation to arterial oxygen levels.

2. How Does the Calculator Work?

The calculator uses the Oxygenation Index formula:

\[ OI = \frac{FiO_2 \times MAP}{PaO_2} \times 100 \]

Where:

\( FiO_2 \) — Fraction of inspired oxygen (0.21-1.0)
\( MAP \) — Mean airway pressure (cmH₂O)
\( PaO_2 \) — Arterial oxygen partial pressure (mmHg)

Explanation: The equation quantifies the relationship between oxygen delivery, airway pressure, and arterial oxygenation, providing a comprehensive assessment of pulmonary function.

3. Importance of Oxygenation Index

Details: The OI is particularly valuable in assessing patients with acute respiratory distress syndrome (ARDS) and guiding mechanical ventilation strategies. Higher OI values indicate more severe oxygenation impairment.

4. Using the Calculator

Tips: Enter FiO₂ as a decimal (0.21-1.0), MAP in cmH₂O, and PaO₂ in mmHg. All values must be positive and within physiological ranges for accurate calculation.

5. Frequently Asked Questions (FAQ)

Q1: What is a normal Oxygenation Index value?
A: Normal OI is typically less than 5. Values above 15 indicate moderate respiratory failure, and values above 30 indicate severe respiratory failure.

Q2: How does OI differ from PaO₂/FiO₂ ratio?
A: OI incorporates mean airway pressure, making it more comprehensive than the PaO₂/FiO₂ ratio, especially for patients receiving mechanical ventilation.

Q3: When is Oxygenation Index most useful?
A: OI is particularly valuable in pediatric and neonatal intensive care, as well as in assessing ARDS severity and response to treatment in adults.

Q4: Are there limitations to the Oxygenation Index?
A: OI may be less accurate in patients with significant hemodynamic instability or those receiving high-frequency oscillatory ventilation.

Q5: How often should OI be calculated?
A: In critically ill patients, OI should be monitored regularly to assess response to therapy and guide ventilator management decisions.