Ans is 'c' i.e. Prophylactic Heparin Patients are at increased risk for developing venous thromboembolism after:Major abdominal surgery Major orthopaedic surgery has sustained, major trauma has prolonged immobility (>3 days)These patients need some form of prophylaxis. The prophylaxis can be mechanical or pharmacological.Prophylaxis for DVT Mechanical prophylaxis includes: i: ' ' ' - V, .V? 'Early ambulation **Pneumatic compression devices **It is the simplest method of prophylaxis It acts by activating the calf pump mechanism It is the most common method of prophylaxisPneumatic compresses prevents the stasis by periodically compressing the calvesPharmacological prophylaxis includes: Use of unfractionated heparin * Use of fractionated low molecular * weight heparin *Now being replaced by fractionated low molecular weight hepatin Better efficacy than unfractionated heparin No laboratory monitoring is necessaryComparison of low molecular weight heparin (LMWH) with mechanical prophylaxis demonstrates superiority of low molecular weight heparin (LMWH) in reduction of the development of venous thromboembolic disease.Prospective trials evaluating LMWH in head injured and trauma patients have also proven safety of LMWH with no increase in intracranial bleeding or major bleeding at other sites. In addition, LMWH shows significant reduction in the development of venous thromboembolism compared to other methods.In short, LMWH should be considered the optimal method of prophylaxis in moderate and high risk patients.Even the traditional reluctance to use heparin in high risk groups such as the multiply injured trauma patient and the injured patient must be reexamined, given the efficacy and safety profile of LMWH in multiple prospective trials.