A 52-year-old woman presents with a 3-day history of acute onset swelling, pain, and warmth in her left lower limb. She returned from a 12-hour flight 5 days ago and has been immobilized due to a recent knee arthroscopy 2 weeks prior. On examination, the left calf is swollen with a positive Homan's sign and pitting edema. Duplex ultrasonography confirms thrombosis in the left popliteal vein. She has no contraindications to anticoagulation. What is the most appropriate immediate management?

Explanation

## Clinical Scenario Analysis This patient has **acute proximal DVT** (popliteal vein involvement) with clear risk factors: recent immobilization (flight + knee arthroscopy). The presentation is classic: acute swelling, pain, warmth, and positive Homan's sign, confirmed on duplex ultrasound. ## Anticoagulation Strategy for Acute DVT **Key Point:** The standard of care for acute DVT without contraindications is **immediate anticoagulation** to prevent pulmonary embolism and reduce post-thrombotic syndrome. ### First-Line Anticoagulation Options | Agent | Route | Advantages | Use in Acute DVT | |-------|-------|-----------|------------------| | **LMWH** | Subcutaneous | Predictable pharmacokinetics, no monitoring, outpatient-friendly | **Preferred initial agent** | | **UFH** | Intravenous | Rapid onset, reversible, short half-life | Alternative if renal failure (CrCl <30) or anticipated need for urgent intervention | | **DOAC** | Oral | No monitoring, convenient | Used after initial parenteral anticoagulation (not monotherapy for acute DVT) | | **Fondaparinux** | Subcutaneous | Weight-based dosing | Alternative if HIT history | **High-Yield:** LMWH is preferred over UFH for acute DVT in most patients because it has superior bioavailability, predictable kinetics (no aPTT monitoring), and can be given as outpatient therapy. ## Duration of Anticoagulation **Clinical Pearl:** For **provoked DVT** (secondary to transient risk factors like immobilization, surgery), anticoagulation duration is **3 months**. Unprovoked DVT typically requires longer duration (3 months minimum, often indefinite). ## Transition to Long-Term Anticoagulation **Key Point:** After initial parenteral anticoagulation (LMWH or UFH), transition to: - **DOAC** (apixaban, rivaroxaban, dabigatran) — preferred in most cases, no INR monitoring - **Warfarin** — if DOAC contraindicated, requires INR target 2–3 ## Why NOT Thrombolysis? **Warning:** Thrombolysis (catheter-directed or systemic) is reserved for: - Massive PE with hemodynamic instability - Acute limb-threatening thrombosis (phlegmasia cerulea dolens) - Extensive iliofemoral DVT with severe symptoms in young patients This patient has uncomplicated proximal DVT — anticoagulation alone is standard. ## Why NOT Conservative Management? **Urgent:** Withholding anticoagulation in acute DVT risks: - Pulmonary embolism (fatal in ~10% if untreated) - Propagation of thrombus - Post-thrombotic syndrome (chronic pain, edema, ulceration) Compression and elevation are **adjuncts**, not alternatives to anticoagulation.