1. Deep vein thrombosis David Hughes

2. Pathophysiology normal deep pelvic/leg veins thrombus (red cells, fibrin) around valves propagation Virchow’s triad (endothelium, coagulability, stasis)

3. Symptoms asymptomatic warm, red, swollen leg unilateral pain, improved by elevation gradual onset superficial venous distension pitting oedema mild fever tachycardia

4. Wells criteria active Ca (Rx last 6/12 or palliative) +1 calf swelling >3cm compared to other calf +1 distended non-varicose superficial veins +1 pitting oedema +1 previous DVT +1 swelling of entire leg +1 localised pain along deep venous system +1 paralysis/paresis/recent cast immobilisation lower limbs +1 recently bedridden > 3/7 or major surgery in past 4/52 +1 alternative diagnosis at least as likely -2

5. Wells interpretation ≥2 - DVT likely, consider imaging leg veins <2 - DVT unlikely, consider D-dimer to further rule out DVT

6. Other predisposing factors age (>40) smoking obesity pregnancy oral contraceptive HRT thrombophilia long-distance flight cardiac failure dehydration

7. Prophylaxis early mobilisation elevation of legs compression stockings LMW heparin weight loss

8. Differential diagnosis cellulitis ruptured Baker’s cyst

9. Investigation calf circumference (calf >3cm than other 10cm below tibial tuberosity) D-dimer (not diagnostic, suggestive but not conclusive) Homan’s sign ill-advised Doppler ultrasonography (iliofemoral) venography (definitive, calf)

10. Treatment bed rest initially elevate leg analgesia compression stocking (post-thrombotic) anticoagulation Rx-dose heparin (1.5mg/kg/24h SC) warfarin for 3-6/12 (INR 2-3) thrombolysis/surgery (extensive, limb- threatening)

11. Complications PE (~10%) post-thrombotic syndrome recurrence DVT (~20%)