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Step 1 · Presentation
Initial assessment
Vitals · O₂ saturation · ECG · CXR · blood gas. Enter the observations — they auto-fill the scores downstream.
yrs
bpm
mmHg
%
Haemodynamically unstable?
Sustained SBP <90 mmHg for ≥15 min, vasopressor requirement, obstructive shock, or cardiac arrest.
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Step 2 · Pretest probability
Wells or Geneva score
Classify clinical probability. Items driven by the vitals above are ticked automatically.
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Step 3 · Rule-out
PERC rule
Low Wells probability — if all 8 PERC criteria are negative, PE is excluded without testing (Kline et al.; endorsed by ACEP/ESC — PERC is not part of NICE NG158, which has no PERC-equivalent rule-out step).
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Step 4 · Biochemistry
D-dimer — YEARS algorithm (UK DDU)
Tick the YEARS criteria, then enter the lab value. The threshold adapts automatically (250 vs 500 ng/mL DDU by criteria count). Note: gating this via a Wells/Geneva pretest score is a pragmatic combination — YEARS itself was validated as its own standalone 3-item rule, not as an add-on to Wells/Geneva.
YEARS criteria
D-dimer result
ng/mL DDU
ng/mL
UK DDU units: most UK labs report D-dimer in DDU (ng/mL); DDU × 2 ≈ FEU. ≥1 YEARS criterion → threshold 250 · no criteria → 500 ng/mL DDU. These are fixed YEARS thresholds — YEARS does not age-adjust (age-adjusted D-dimer is a separate strategy for the conventional Wells+D-dimer pathway, not used here). Always check your local assay's reference range.
⚠ D-dimer may be unreliable in: high pretest probability · active malignancy · pregnancy >20 weeks · surgery <4 weeks · acute illness/sepsis · anticoagulated patients. Apply clinical judgement.
↗ Full YEARS algorithm in Clinical Scores
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Step 5 · Imaging
Confirm or exclude PE
CTPA is the preferred test (Class I, B-R).
Imaging result
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Step 6 · Risk stratification
Severity, biomarkers & RV assessment
Enter what you have — the suggested category (A–E, 2026 AHA/ACC) updates live. SBP is carried over from Step 1.
ng/L
pg/mL, BNP only
mmol/L
mmHg
pts
/6
Assign category
⚠ Algorithmic suggestion only — clinical judgement and local protocols prevail.
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Step 7 · Treatment & disposition
Management plan
Full 2026 AHA/ACC management for the assigned category, plus anticoagulation reference.
Pathway summary