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PERC rule: PE rule-out criteria

Respiratory & VTE

In a low-pretest-probability patient (clinician gestalt <15%), if all eight are negative, PE is excluded without a D-dimer.

What you enter

  • Age ≥50 (+1)
  • Heart rate ≥100 (+1)
  • SpO₂ <95% on room air (+1)
  • Unilateral leg swelling (+1)
  • Haemoptysis (+1)
  • Surgery or trauma in the last 4 weeks (+1)
  • Previous DVT / PE (+1)
  • Exogenous oestrogen (+1)
FORMULAAll 8 negative + low clinical probability = no further testing
SourceKline JA et al. Prospective multicenter evaluation of the pulmonary embolism rule-out criteria. J Thromb Haemost 2008;6:772-80ReviewedFormula and thresholds checked against the source on 2026-08-22. If the source updates, this line will say so.