Haematology and Oncologyniche
A 66-year-old woman is on day 8 after an elective total hip replacement and has been receiving subcutaneous enoxaparin 40 mg daily since surgery. Her platelet count was 245 × 10⁹/L on admission; today it is 74 × 10⁹/L. She has developed a painful swollen left calf, and a Doppler ultrasound confirms a popliteal vein thrombosis. She has no bleeding. Her renal function is normal.
Which one of the following is the most appropriate management?