What Wells PE score indicates high, moderate, and low probability?

Three-tier: Low probability ≤1; Moderate probability 2-6; High probability ≥7; Two-tier: PE unlikely ≤4; PE likely >4. High probability warrants CT-PA directly; low probability with negative PERC rule: no further workup needed.

What are the PERC rule criteria?

All 8 must be absent to pass PERC (no further workup): age <50, HR <100, SpO2 ≥95%, no unilateral leg swelling, no hemoptysis, no recent surgery/trauma, no prior DVT/PE, no estrogen use; only apply with Wells/clinical low probability.

What age-adjusted D-dimer cutoff should be used?

For patients >50 years: age-adjusted D-dimer cutoff = age × 10 mcg/L (e.g., 70 years = 700 mcg/L); conventional threshold 500 mcg/L; age-adjusted threshold reduces false-positive rate from 20% to 5% in elderly without missing more PEs.

When should CTA be performed without D-dimer?

High pre-test probability (Wells ≥7 or clinical gestalt) warrants direct CTA-PA; D-dimer has poor specificity in high probability and a positive result does not change management; negative D-dimer with high probability still requires imaging.

What is subsegmental PE and how should it be managed?

Subsegmental PE (isolated to subsegmental arteries without proximal PE): management debated; anticoagulation generally recommended if no cardiopulmonary reserve, malignancy, or high clot burden; observation alone reasonable for isolated peripheral findings with low clot burden and low risk.

Wells PE Score and PERC Rule for Pulmonary Embolism

Calculates Wells score for pulmonary embolism pre-test probability with integration of PERC rule for low-risk patients, Geneva score alternative, and D-dimer age-adjusted threshold guidance.

Weight

Height

Clinical Guidance

BMI is a screening measure of body size, not a direct measure of body fat. The standard WHO categories are underweight (<18.5), normal (18.5–24.9), overweight (25–29.9), and obese (≥30).

BMI can overestimate body fat in athletes with high muscle mass and underestimate it in older adults with low muscle mass. Interpret it alongside waist circumference and clinical context rather than as a standalone diagnosis.

⚕ Clinical Disclaimer: These calculators are for educational and reference purposes only. Always verify results with qualified clinical judgment and current clinical guidelines. Do not use as a sole basis for medical decisions.

How to Use

Enter the values for the patient or scenario you are assessing. Calculates Wells score for pulmonary embolism pre-test probability with integration of PERC rule for low-risk patients, Geneva score alternative, and D-dimer age-adjusted threshold guidance. Use the wells pe score result to inform your clinical assessment.

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