Mnemonic

Pulmonary Embolism Assessment

A memory aid for the Wells score and the PE diagnostic pathway.

Expansion

Score first, then D-dimer or CT pulmonary angiogram

Expansion

Wells score for PE

  • Clinical signs of DVT: 3
  • PE is the most likely diagnosis: 3
  • Heart rate over 100: 1.5
  • Immobilisation over 3 days or surgery within 4 weeks: 1.5
  • Previous DVT or PE: 1.5
  • Haemoptysis: 1
  • Malignancy treated within 6 months: 1

Interpretation

  • Above 4: PE likely. Immediate CTPA, with interim anticoagulation if delayed
  • 4 or less: PE unlikely. D-dimer; if negative, PE is excluded; if positive, CTPA

“The two 3 pointers are the clinical ones”, and they alone can make PE likely.

PERC rule may exclude PE without any test in a very low risk patient where all eight criteria are negative.

V/Q scan rather than CTPA in pregnancy, renal impairment and contrast allergy, particularly where the chest radiograph is normal.

ECG most often shows sinus tachycardia; the classic S1Q3T3 is uncommon and non-specific. Massive PE with haemodynamic instability is an indication for thrombolysis.