Preventing Venous Thromboembolism in Hospitalized Patients: Recommendations From the American College of Physicians FREE

The American College of Physicians (ACP) developed these recommendations. Members of ACP are internists—specialists in the care of adults.

In venous thromboembolism (VTE), blood clots form in veins, often in the legs. Pieces of these leg clots can break off and travel to the lungs, a serious condition called pulmonary embolism. Factors that increase the risk for VTE include immobility (such as long plane rides or being sick in bed), some medications, and some medical conditions (including cancer).

Injections of small doses of the blood thinners unfractionated heparin or low-molecular-weight heparin can prevent VTE. Because many hospitalized patients have VTE risk factors, many hospitals routinely give patients blood thinners to prevent VTE. However, these medications can cause bleeding. Bleeding due to these medications is usually mild, through the gastrointestinal tract or skin wounds. However, it can be severe and occur in a critical organ, such as the brain. Another way to prevent VTE is to put mechanical devices that squeeze the lower part of patients' legs to prevent clots from forming. These devices are uncomfortable, can cause skin breakdown, and might have the unwanted effect of keeping patients in bed.

The ACP wanted to develop recommendations on the best strategies for preventing VTE in hospitalized patients.

The ACP reviewed studies on the benefits and harms of blood thinners and mechanical devices for preventing VTE in patients hospitalized for medical illnesses or stroke and who did not have surgery. The outcomes of interest were patient death up to 120 days after being hospitalized, symptomatic leg vein clots, pulmonary embolism, death from pulmonary embolism, any bleeding, major bleeding, and skin breakdown. The ACP considered the quality and strength of the available information when making these recommendations.

Available information shows that using heparin to prevent VTE decreases pulmonary embolism in nonsurgical patients, does not decrease death rates, and leads to more bleeding complications. No differences in benefits or harms were found between the types of heparin used. Mechanical devices provided no benefit and caused side effects.

Assess the risk for VTE and bleeding in medical patients and patients with stroke before starting VTE prevention.

Do not use blood thinners to prevent VTE in hospitalized nonsurgical patients unless the risk for VTE is greater than the risk for bleeding.

Do not use mechanical devices to prevent VTE in hospitalized nonsurgical patients.

Hospital performance measures should not promote universal VTE prevention regardless of a patient's individual risks for VTE and bleeding.

These recommendations do not apply to patients hospitalized for surgery. Surgical patients have different risk levels for both VTE and bleeding than nonsurgical patients.