Recommendations have been made for thromboprophylaxis of high-risk medical patients while they are hospitalized.
For hospitalized medical patients who are at increased risk of thrombosis, anticoagulant thromboprophylaxis with low molecular weight heparin, low dose unfractionated heparin twice or three times a day, or fondaparinux have been recommended.
Since many episodes of venous thromboembolism occur within weeks after hospitalization extended thromboprophylaxis is recommended.
A report suggested that 23% of patients admitted for acute pulmonary embolism had recent surgery and another 37% have been hospitalized for a medical condition within the prior three months.
An incidence of venous thromboembolism of 3.8% occurs within 100 days after discharge of high risk medical patients.
Protocols for thromboprophylaxis after discharge of patients for various types of surgery, major trauma, and spinal cord injuries exist and such protocols reduce the incidence of venous thromboembolism after hospital discharge and save lives.
Enoxaparin 40 mg once daily for 6-14 days in medical patients hospitalized for severe acute cardiac, respiratory, infectious or rheumatic disorders have a significantly decreased risk of thromboembolism.
In a trial of dalteparin vs unfractionated heparin randomly assigned in 3764 patients, and given subcutaneoulsy 5000 u daily or 5000 u bi, respectively in ICU patients: among critically ill patients dalteparin was not superior to unfractionated heparin in decreasing the incidence of proximal deep vein thrombosis (PROTECT Investigators).
In the above study the rates of venous thrombosis, venous thromboembolism, major bleeding, and death was similar in the two groups although the number of pulmonary emboli was fewer in the dalteparin group, 100 patients would need to undergo prophylactic treatment with this drug rather than unfractionated heparin to prevent one pulmonary embolism.
Patients with extremity fractures, treated operatively or with pelvic acetabulum fracture, thromboprophylaxis with aspirin is not inferior to low molecular weight, heparin in preventing death is associated with low incidence of deep vein thrombosis and pulmonary embolism and low 90 day mortality (Major Extremity Trauma Research, Consortium).