This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
A 60 year old male has been operated for carcinoma of caecum and right hemicolectomy has been done. On the 4th post-operative day, the patient develops fever, swelling and pain in the legs. The most impoant clinical entity one should look for is: March 2011 
Select and explain. 
A. Urinary tract infection, B. Intravenous line infection, C. Chest infection, D. Deep vein thrombosis
D: Deep vein thrombosis
Answer: D: Deep vein thrombosis 
Explanation: Ans. D: Deep vein thrombosis Stasis is a predisposing factor for DVT, especially in the post-operative period Increasing age and trauma/ surgery, especially of the pelvis, hip and lower limb is a risk factor for DVT The most common presentation of a DVT is pain and swelling, especially in the calf of one lower limb DVT: DVT of the iliac, femoral, popliteal veins is suggested by unilateral leg swelling, warmth, pain and erythema Homan's sign: Forced dorsiflexion of the ankle causes pain in the calf The non-invasive test used most often to diagnose DVT is duplex venous USG Heaprin is used for DVT prophylaxis Bandaging and thrombolytic therapy is effective