PERC Calculator: Pulmonary Embolism Rule-Out Criteria for PE Risk Assessment

Calculate PERC Score: Pulmonary Embolism Rule-Out Criteria

Quickly determine if a patient is at low risk for pulmonary embolism (PE) using our online PERC Calculator. This tool helps clinicians apply the Pulmonary Embolism Rule-Out Criteria to potentially avoid unnecessary imaging, ensuring efficient and safe patient management and reducing healthcare costs.

Formula:

The PERC (Pulmonary Embolism Rule-Out Criteria) score is not a numerical sum but a set of 8 clinical criteria used to safely rule out PE in patients with a low pretest probability. If ALL 8 criteria are negative (i.e., the patient meets all 8 PERC criteria), the PERC score is 0, and PE can be safely ruled out. If ANY ONE of the 8 criteria is positive, the PERC score is >0, and PE cannot be ruled out by PERC alone. The PERC score is typically applied to patients with a low clinical probability of PE.

The 8 PERC criteria are:

  • Age < 50 years
  • Heart rate < 100 beats/min
  • Oxygen saturation ≥ 95% on room air
  • No unilateral leg swelling
  • No hemoptysis
  • No recent trauma or surgery (within 4 weeks)
  • No prior history of venous thromboembolism (VTE)
  • No estrogen use

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