• Diagnosis: 

• if Well's ≥2 or or d-dimer +, for USS within 4 hours (if not available, start anticoagulation e.g. LMWH)

Wells

• Active cancer (treatment ongoing, within 6M or palliative) (1)

• Paralysis, paresis or recent leg plaster immobilization of the lower extremities (1)

• Bedridden >3/7 (1)

• Major surgery in the last 12/52 requiring general or regional anaesthesia (1)

• Localised tenderness along the distribution of the deep vein system (1)

• Entire leg swollen (thigh/calf) (1)

• Calf circumference difference >3cm (10cm below tibial tuberosity) (1)

• Pitting oedema confined to the affected leg (1)

• Dilated (non-varicose) superficial veins in the affected leg (1)

• Previous documented DVT (1)

• Alternative diagnosis is at least as likely as DVT (-2)

Management (GSTT): 

• Rivaroxaban PO or, if contraindicated, dalteparin s/c. Check creatinine clearance (Cockcroft-Gault equation) to calculate dose

• Wells Score (DVT) (DVT risk assessment), Deep vein thrombosis (CKS)​, Deep vein thrombosis (NHS Choices)

Gold standard investigation for diagnosis of a PE is computed tomography pulmonary angiography (CTPA).

If a pulmonary embolism is suspected, the patient should be admitted to hospital for same day assessment. Once in hospital, the management depends on the Wells score. This patient scores more than 4 on the Wells scoring system. If the Wells score is greater than 4, computed tomography pulmonary angiography (CTPA) is recommended. If it is 4 or less, a D-dimer blood test should be performed followed by a CTPA. If there is likely to be a delay of four hours or more, interim anticoagulation should be offered.

Wells

• Clinical signs of DVT (3)

• Alternative diagnosis less likely that PE (3)

• Previous DVT/PE (1.5)

• Recent surgery/immobilisation (1.5)

• HR >100 (1.5)

• Cancer (1)

• Haemoptysis (1)

Low - PE unlikely (≤4): D-dimer negative (no imaging, consider other diagnosis), positive (VQ SPECT or CTPA)

PE likely (>4): VQ or CTPA. PE diagnosed: PESI score

Pulmonary embolism severity index (PESI) score

• Age (+1 per year)

• Male (+10)

• Cancer (+30)

• Chronic heart failure (+10)

• HR ≥110 (+20)

• Systolic BP <100 (+30)

• RR>30 (+20)

• Temp <36 (+20)

• Altered mental state (+60)

• Sats <90% (+20)

≤85 PESI score 1-2, low/v.low mortality risk):

≥86 (PESI score 3-5, mod/high mortality risk): 

Interim anticoagulation for suspected PE: e.g. Rivaroxaban/Apixaban, or LMWH

Confirmed PE: anticoagulation e.g. warfarin, apixaban, dabigatran, edoxaban, rivaroxaban

Resources

• Pulmonary Embolism (CKS), Pulmonary Embolism (NHS Choices), Venous Thromboembolism (VTE) (NHS Choices)​​, Wells Score (PE)​ (PE risk assessment)

• Venous Thromboembolic Diseases: diagnosis, management and thrombophilia testing (NG 158, 2020)