Synopsis
Apply the NICE two-level Wells pathway, avoid unsafe diagnostic delay and choose initial anticoagulation with UK-specific modifiers.
- Use the 2-level DVT Wells score: 2 points or more means DVT likely; 1 point or less means DVT unlikely.
- Likely DVT: obtain proximal leg-vein ultrasound within 4 hours if possible; if delayed, give interim therapeutic anticoagulation and scan within 24 hours.
- Unlikely DVT: obtain D-dimer within 4 hours; if delayed, give interim therapeutic anticoagulation while awaiting the result.
Key red flags
Massive painful swelling, cyanosis, sensory/motor change or threatened perfusion from extensive venous occlusion requires emergency vascular/haematology assessment.
Investigation priorities
Set the NICE diagnostic pathway before testing.
Management branches
Clinically suspected DVT with a likely 2-level Wells score.
- First: proximal leg-vein ultrasound with result within 4 hours if possible.
- Next: if ultrasound cannot be obtained within 4 hours, take D-dimer, give interim therapeutic anticoagulation and obtain ultrasound within 24 hours.
A condition that makes routine DOAC treatment uncertain or unsuitable.
Key medicines
Apixaban10 mg orally twice daily for 7 days, then 5 mg twice daily; if extended prevention is chosen after 6 months, 2.5 mg twice daily.
Rivaroxaban15 mg orally twice daily with food for 21 days, then 20 mg once daily with food; after at least 6 months, 10 mg once daily (or 20 mg once daily if recurrence risk is high).