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PaO₂/FiO₂ Ratio (PAFI / Horovitz Index) Calculator

Critical care cornerstone metric (Berlin ARDS Definition JAMA). Stratifies ARDS on PEEP ≥ 5 in Mild (200-300), Moderate (100-200), and Severe (≤100).

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Adjust values on the left to calculate live results.

Formula: PAFI Ratio = PaO₂ (mmHg) / (FiO₂ % / 100). Normal: 400-500 mmHg. Berlin ARDS Criteria: Mild (200-300), Moderate (100-200), Severe (≤100).

In-Depth Guide & Mathematical Methodology

💨 Berlin ARDS Criteria & Mortality

Normal (> 300 mmHg): Normal oxygenation.

Mild ARDS (200 - 300 mmHg): ~27% ICU mortality. Protective ventilation (6 mL/kg PBW).

Moderate ARDS (100 - 200 mmHg): ~32% ICU mortality. High PEEP titration strategy.

Severe ARDS (≤ 100 mmHg): ~45% ICU mortality. Prone positioning ≥ 16h/day, neuromuscular blockade, ECMO consideration.

Frequently Asked Questions (FAQ)

What is the PaO₂/FiO₂ Ratio (PAFI / Horovitz Index) Calculator and how does it work?

Critical care cornerstone metric (Berlin ARDS Definition JAMA). Stratifies ARDS on PEEP ≥ 5 in Mild (200-300), Moderate (100-200), and Severe (≤100).

How do I use this PaO₂/FiO₂ Ratio (PAFI / Horovitz Index) Calculator?

Enter arterial PaO₂ in mmHg from ABG. Enter FiO₂ as percentage (21% to 100%). View calculated PAFI ratio and Berlin ARDS severity classification.

What mathematical formula is used in this calculation?

PAFI Ratio = PaO₂ (mmHg) / (FiO₂ % / 100). Normal: 400-500 mmHg. Berlin ARDS Criteria: Mild (200-300), Moderate (100-200), Severe (≤100).

Is the PaO₂/FiO₂ Ratio (PAFI / Horovitz Index) Calculator on FindCalculator free to use?

Yes, all 330+ interactive tools on FindCalculator.online are 100% free, run directly in your browser without registration, and do not store your private calculation data.

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