Low-molecular-weight heparin.

Traditionally unfractionated heparin is given in the hospital and then followed with 3 to 6 months of oral anticoagulant therapy. Hospitalization is expensive, intravenous administration of heparin limits mobility, and the patient is exposed to iatrogenic infections. Depolymerization of heparin results in low-molecular-weight heparin (LMWH), which has advantages over unfractionated heparin. The advantages are better bioavailability, a longer half life, and more predictable anticoagulant activity. Because of these characteristics it can be given subcutaneously, without laboratory monitoring, in a dose that is calculated by the patient's body weight alone. Studies have shown that LMWH is as effective as unfractionated heparin at preventing clot extension and pulmonary emboli. and is possibly safer. There are a number of LMWH preparations available worldwide, and clinical trials have been conducted in a number of countries. This article will review the clinical properties, uses, complications, and nursing implications associated with LMWH.