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PERC Rule (Pulmonary Embolism Rule-out Criteria): Explanation and Clinical Context The PERC Rule is a clinical decision tool used to identify patients with a very low probability of pulmonary embolism (PE), in whom further diagnostic testing can be safely avoided. It includes 8 criteria: age > 50 years, heart rate > 100 bpm, oxygen saturation < 95%, prior history of PE or DVT, recent surgery or trauma, hemoptysis, estrogen use, and unilateral leg swelling. If a patient meets none of these criteria (PERC negative), the risk of PE is extremely low, and testing such as D-dimer or imaging may be unnecessary in low-risk patients.
If any criteria are positive (PERC positive), further evaluation is warranted based on clinical context.
Evidence & references1 primary source mapped
- Source 1
Kline JA, et al. "Clinical criteria to prevent unnecessary diagnostic testing in emergency department patients with suspected pulmonary embolism." J Thromb Haemost. 2004;2(8):1247-1255. doi:10.1111/j.1538-7836.2004.00860.x
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