Health

PERC Rule Calculator

Rule out PE in low-risk patients without further testing.

Age ≥ 50?

HR ≥ 100?

SpO₂ < 95%?

Unilateral leg swelling?

Hemoptysis?

Recent surgery/trauma (last 4 wk)?

Prior PE or DVT?

Hormone use (OCP/HRT)?

PERC Rule

The PERC rule is used ONLY in low-risk patients (gestalt < 15% pretest probability). If ALL 8 criteria are absent, PE can be excluded without D-dimer (miss rate < 1.8%). Any single positive criterion fails the PERC rule and requires further workup. PERC should not be applied to moderate or high pretest probability patients.