Critical Care Equation Strong evidence Clinical review pending v1.0.0

PaO₂/FiO₂ (P/F) Ratio

How severe is impaired oxygenation (ARDS category)?

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cmH₂O
Berlin categories require PEEP/CPAP ≥ 5 cmH₂O.
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About this tool

Oxygenation ratio with Berlin ARDS severity categories.

Intended use

Patients with an arterial blood gas and known FiO₂.

Outcome

Oxygenation severity

Time horizon

Point in time

Limitations

  • Depends on PEEP and FiO₂; categories assume PEEP ≥ 5 cmH₂O.

Clinical problems

Evidence

Evidence level

Strong evidence

Derived and externally validated in multiple cohorts (including prospective studies) and incorporated into major clinical guidelines. Methodology

Guideline status

Core oxygenation criterion of the Berlin ARDS definition (2012) and 2023 global definition.

Evidence summaries for this tool are awaiting independent clinical review. Statistics are shown only where they could be attributed to a specific publication.

References

  1. GuidelineARDS Definition Task Force; Ranieri VM, Rubenfeld GD, et al. Acute respiratory distress syndrome: the Berlin Definition. JAMA 2012;307:2526-2533. Find on PubMed (opens in a new tab)
  2. GuidelineMatthay MA, Arabi Y, Arroliga AC, et al. A New Global Definition of Acute Respiratory Distress Syndrome. Am J Respir Crit Care Med 2024;209:37-47. Find on PubMed (opens in a new tab)

Version history

VersionFormulaEffectiveReviewerChanges
v1.0.0PaO2 ÷ FiO2; Berlin 20122026-10-03—Initial implementation with reference test vectors.

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Clinical decision support only. Interpret results in the context of the individual patient and current guidance; HumanPulse does not replace professional medical judgment.