Venous Thromboembolism (VTE) is common in the intensive care unit (ICU); VTE leads to significant morbidity and is fatal in 30% of undiagnosed pulmonary emboli and 8% when PE is appropriately treated. Intensive care unit (ICU) patients have multiple risk factors for VTE and tend to be at higher risk than non-ICU patients. Risk factors specific to ICU patients include immobility, central venous catheters, sepsis or infection, need for vasopressors, mechanical ventilation, surgery, trauma, and increasing age. Guidelines exist for the prevention of VTE, and VTE prophylaxis is strongly recommended. Given the high rate of VTE and the attendant morbidity and mortality, most ICU's routinely provide VTE prophylaxis which is individualized according to risk-benefit analysis with respect to thrombosis and bleeding risk. Prophylaxis for patients at risk of bleeding is accomplished by using mechanical compression devices while those without bleeding risk are administered medical prophylaxis which is felt to be more effective.