**Venous Thromboembolism** [Image of a diagram showing a leg with various veins labeled: IVC, iliac, femoral, popliteal, tibial, peroneal, and distal veins] **Risk factors:** * **Virchow's Triad:** * Venous stasis * Hypercoagulability * Endothelial injury **Venous stasis:** * Immobility * Surgery * Pregnancy * Heart failure * Obesity **Hypercoagulability:** * Factor V Leiden * Prothrombin G20210A * Antithrombin deficiency * Protein C deficiency * Protein S deficiency * Antiphospholipid syndrome **Endothelial injury:** * Trauma * Surgery * Catheters * Infection **Presentation:** * **DVT:** * Venous blood back-up * Swelling * Pain * Warmth * Homan's sign (pain with dorsiflexion) * **PE:** * Sudden shortness of breath * Pleuritic chest pain * Tachycardia * Tachypnea * Hemoptysis * Syncope * Sudden death **Diagnosis:** * **D-dimer:** Elevated * **Doppler ultrasound:** Identifies DVT * **CT pulmonary angiography:** Identifies PE **Treatment:** * Anticoagulation: * Heparin (IV or subcutaneous) * Warfarin * Novel oral anticoagulants (NOACs) * Thrombolysis: * For massive PE or impending limb loss * Inferior vena cava (IVC) filter: * For recurrent DVT or contraindications to anticoagulation * Surgical embolectomy: * Rarely used **Prevention:** * Early mobilization after surgery * Compression stockings * Anticoagulation prophylaxis * Avoid prolonged sitting or standing **Issues with DVT** * Post-thrombotic syndrome * After clot dissolving clot * **Legs not good** * **Moving blood** * **As they should** * **Venous congestion** * **Blue limb** * **Phlegmasia Cerulea Dolens** **If intense compression of nearby a** **Chronic venous insufficiency** **Clot breaking off** **IVC** **PE** **-> Reduced circulation** **-> Reduced BF to lung** **-> Pulmonary Embolism** **-> Reduced BF to heart** **-> Reduced CO** **-> HF** **Diagnostic Approach to DVT** **Low Probability (Score of 0)** **Moderate Probability (Score of 1-2)** **High Probability (Score of 3)** **D-Dimer < 500** **D-Dimer ≥ 500** **Ultrasound** **DVT excluded** **DVT confirmed** **Simplified Well's Score** **(Pretest Probability of DVT)** **Previous DVT/PE** **Active cancer diagnosis** **Recent immobilization/bedridden** **Localized tenderness along venous distribution** **Leg swelling** **Asymmetric calf swelling** **Pitting edema** **Collateral superficial veins** **Alternative diagnosis more likely (1-2 points)**