P/F ratio and Berlin ARDS severity
PaO₂/FiO₂ ratio with Berlin ARDS severity category.
Inputs
0 of 2%
When to use
- Arterial blood gas on known FiO₂.
Pearls and pitfalls
- Berlin also requires onset within 1 week, bilateral opacities, and edema not fully explained by heart failure.
- The 2023 global definition adds SpO₂/FiO₂ and high-flow oxygen.
Why use
The core oxygenation measure in ARDS.
P/F = PaO₂ ÷ FiO₂; ARDS (PEEP ≥ 5): 200–300 mild, 100–200 moderate, ≤ 100 severe