Which of the following is the best way of preventing the development of deep vein thrombosis (DVT) in the postoperative period

Patients are at increased risk for developing venous thromboembolism after: Major abdominal surgery Major ohopaedic 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 include : Early ambulation It is the simplest method of prophylaxis It acts by activating the calf pump mechanism Pneumatic compression devices It is the most common method of prophylaxis Pneumatic compresses prevents the stasis by periodically compressing the calves. Pharmacological Prophylaxis include Use of unfractionated heparin - Now being replaced by fractionated low molecular weight heparin Use of fractionated low molecular - Better efficacy than unfractionated heparin weight heparin - No laboratory monitoring is necessary