Suspected Pulmonary Embolism at the Bedside
A brief placeholder lead on PE presentation and why risk stratification matters.
- ~1–2/1000: Annual PE incidence (placeholder population rate)
- ~30%: Untreated mortality (placeholder historical estimate)
- 2–3: Common symptoms (dyspnea, pleuritic pain, tachycardia)
- 1998–2000: Wells published (placeholder derivation years)
Why pretest probability comes first
Placeholder: symptoms are nonspecific, so structured scoring guides testing.
Placeholder: avoids over-testing low-risk patients and under-testing high-risk ones.
Assessing the Wells Criteria Checklist
Placeholder lead describing each of the seven weighted clinical criteria.
- 7: Total criteria (placeholder count)
- 12.5: Max possible score (placeholder ceiling)
- 3 pts: Highest weight item (DVT signs or PE most likely)
- 1 pt: Lowest weight item (hemoptysis or malignancy)
Criterion weighting rationale
Placeholder: each criterion weighted by its historical association with confirmed PE.
Placeholder: subjective item (alternative diagnosis) carries highest weight.
Summing Points into a Continuous Wells Score
Placeholder lead on how checked criteria sum into a single numeric score.
- 0–12.5: Score range (placeholder scale)
- Live: Update speed (recomputed on every toggle)
- 0.5 pt: Rounding (placeholder granularity)
- 2: Models supported (three-tier and two-tier)
From checklist to gauge
Placeholder: gauge needle position reflects current summed score.
Placeholder: thresholds vary by chosen scoring model.
Mapping Score to Pretest Probability Tier
Placeholder lead on low/moderate/high versus PE-likely/unlikely tiers.
- <2 pts: Three-tier low (placeholder cutoff)
- >6 pts: Three-tier high (placeholder cutoff)
- 4 pts: Two-tier cutoff (unlikely vs likely)
- ~67%: High-tier prevalence (placeholder PE rate)
Three-tier vs two-tier models
Placeholder: three-tier offers finer stratification.
Placeholder: two-tier simplifies decisions for D-dimer use.
Routing to D-Dimer or Direct CT Angiography
Placeholder lead on the branching pathway triggered by risk category.
- D-dimer: Low-risk pathway (placeholder rule-out step)
- Direct CTPA: High-risk pathway (placeholder confirmatory step)
- ~95%: D-dimer sensitivity (placeholder assay figure)
- ~96%: CTPA specificity (placeholder imaging figure)
Why the pathway branches
Placeholder: D-dimer safely excludes PE in low-probability patients.
Placeholder: high-probability patients skip straight to imaging.
Placeholder key insight: score-driven pathway reduces unnecessary CT scans.