PE_Diagnostic_Flowchart_Presentation.pptx

Pulmonary embolism

1. Pulmonary Embolism (PE) Diagnostic Approach Stepwise evaluation of suspected PE using Wells Score, D-dimer, and imaging.

2. 1. Wells Score for PE **High Risk (>6 points):** - PE is likely → **Go directly for CTPA** (D-dimer not needed). **Moderate Risk (2-6 points):** - Check **D-dimer**. **Low Risk (<2 points):** - If **D-dimer <500 ng/mL** → PE ruled out. - If **D-dimer >500 ng/mL** → Proceed to **CTPA**.

3. 2. D-dimer Interpretation - **Standard Cutoff:** >500 ng/mL (0.5 mg/L) - **Age-Adjusted Cutoff:** Age × 10 ng/mL (for age >50 years) - **Massive PE:** Often **>5000 ng/mL**, but not diagnostic alone.

4. 3. Imaging for PE Confirmation **CT Pulmonary Angiography (CTPA):** - **Gold standard** for diagnosing PE. - Identifies clot location and severity. **V/Q Scan:** - Used in patients with kidney disease or contrast allergy. - Low probability scan rules out PE in low-risk patients.

5. 4. Summary & Take-Home Points - **Use Wells Score first!** - **Low-risk + negative D-dimer → No PE.** - **High-risk → Skip D-dimer, go to CTPA.** - **D-dimer is sensitive but NOT specific; always confirm with imaging.**