PERC Rule
Pulmonary Embolism Rule-out Criteria for low-risk patients.
IMPORTANT: PERC applies ONLY to patients with LOW clinical suspicion for PE.
PERC Criteria
PERC Result
Negative
PE ruled out (if low pretest probability)
No Testing Needed
- • PE is effectively ruled out
- • D-dimer NOT indicated
- • Consider alternative diagnoses
The 8 PERC Criteria
✓ Age ≥ 50 years
✓ Heart rate ≥ 100 bpm
✓ O2 saturation < 95%
✓ Unilateral leg swelling
✓ Hemoptysis
✓ Recent trauma/surgery (4 wks)
✓ Prior DVT or PE
✓ Hormone use (OCP, HRT)
Reference: Kline JA, et al. J Thromb Haemost 2004.
Frequently Asked Questions
How to Use
About the PERC Calculator
What it calculates
This perc calculator applies a validated clinical scoring method used in healthcare settings. PE rule-out criteria.
When to use it
Use as a clinical decision support aid alongside professional judgment — not as a standalone diagnosis.
Example
Adjust the inputs above to model your specific scenario with the PERC Calculator.
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