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Suspected deep vein thrombosis after lower-limb immobilisation — MSRA MCQ

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HardAnkle and FootSuspected deep vein thrombosis after lower-limb immobilisationMSRA

A 46-year-old man attends an urgent treatment centre 10 days after a stable Weber B ankle fracture. He had a below-knee plaster cast for 7 days and has used a walking boot for the past 3 days. He reports 24 hours of increasing left calf pain and swelling without new trauma. He has no chest pain, dyspnoea or haemoptysis. The calf is 4 cm larger in circumference than the right, with localised tenderness along the deep venous distribution. There is no focal muscle tear, cellulitis, or evidence that the walking boot is excessively tight. He has no previous VTE, active cancer, bleeding disorder, renal impairment, recent gastrointestinal bleeding, or anticoagulant use. His 2-level DVT Wells score is 3. Proximal leg vein ultrasound cannot be obtained within 4 hours. What is the most appropriate management today?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: D — Take a D-dimer sample, start interim therapeutic anticoagulation, and arrange proximal leg vein ultrasound within 24 hours

Explanation lettering: B = shown as A · C = shown as B · A = shown as C

This man has a DVT-likely Wells score (3): recent plaster immobilisation of the lower limb, calf swelling of at least 3 cm, and localised deep venous tenderness. The absence of a credible alternative diagnosis means that the minus-2 alternative-diagnosis criterion should not be applied. This is therefore not an "unlikely DVT" pathway. For likely DVT, NICE recommends proximal leg vein ultrasound with a result available within 4 hours where possible. If this cannot be achieved, a D-dimer sample should be taken, interim therapeutic anticoagulation started, and ultrasound arranged with a result available within 24 hours. D-dimer testing does not justify delaying anticoagulation in this circumstance. A is the pathway for an unlikely Wells score. B would be appropriate only if ultrasound were available within 4 hours; otherwise interim anticoagulation is required if there is no contraindication. C risks committing the patient to unnecessary treatment before confirmation. E inappropriately discounts objective features that make DVT more likely than routine post-injury swelling. ([nice.org.uk](https://www.nice.org.uk/guidance/ng158/chapter/recommendations?utm_source=openai))

Reference: NICE NG158: Venous thromboembolic diseases: diagnosis, management and thrombophilia testing — Recommendations (Published 26 March 2020; last updated 2 August 2023) — https://www.nice.org.uk/guidance/ng158/chapter/recommendations NICE NG158: Venous thromboembolic diseases: diagnosis, management and thrombophilia testing — Recommendations (Published 26 March 2020; last updated 2 August 2023) — https://www.nice.org.uk/guidance/ng158/chapter/recommendations