Prevention of venous thromboembolism in high-risk surgical and medical patients

Although pharmacologic prophylaxis against venous thromboembolism has become the standard of care following total hip and knee replacement, prophylaxis among patients undergoing surgery for hip fracture and other lower extremity trauma remains underutilized. Available experience consistently supports the view that low-molecular-weight heparins are more effective than unfractionated heparin for prevention of proximal deep vein thrombosis (DVT) with no additional hemorrhagic risk and more effective than oral anticoagulants for prevention of in-hospital (mostly distal) venous thrombosis at the price of a higher surgical site bleeding and wound hematoma. The choice between low-molecular-weight heparin and warfarin should be tailored to the individual patients based on the clinical assessment of postoperative thrombosis and bleeding risk as well as the prophylaxis-specific cost and convenience. Whether thromboprophylaxis should be continued for a few additional weeks after hospital discharge is controversial. The overall incidence of postoperative DVT in patients with cancer is about twice as high as that of patients free of malignancy. Accordingly, they require prophylactic measures comparable with those usually recommended for major orthopedic surgery. In this setting, dermatan sulfate shows promise. In contrast to surgical patients, prevention of venous thromboembolism is less well studied in hospitalized medical patients. In a recent controlled randomized trial, enoxaparin in high prophylactic doses was an effective and safe measure of thromboprophylaxis in ordinary bedridden patients.