Expansion
Score first, then D-dimer or ultrasound accordingly
Expansion
Wells score for DVT, each scoring 1 unless stated:
- Active cancer
- Paralysis, paresis or recent immobilisation of the leg
- Recently bedridden over 3 days or major surgery within 12 weeks
- Localised tenderness along the deep venous system
- Entire leg swollen
- Calf swelling over 3 cm compared with the other leg
- Pitting oedema confined to the symptomatic leg
- Collateral superficial veins
- Previous documented DVT
- Alternative diagnosis at least as likely: minus 2
Pathway
- 2 or more (DVT likely): proximal leg vein ultrasound within 4 hours, or interim anticoagulation and a scan within 24 hours. If the scan is negative, do a D-dimer and repeat the scan at 6 to 8 days if positive
- 1 or less (DVT unlikely): D-dimer. If negative, DVT is excluded. If positive, proceed to ultrasound
Anticoagulate with a DOAC for at least 3 months, extended to 6 in active cancer, and considered indefinitely after an unprovoked event.
Look for a cause: an unprovoked DVT in an older patient warrants a careful history, examination and basic tests for malignancy, though routine extensive cancer screening is not recommended.