New perspectives for treatment of pulmonary embolism.

Subcutaneous low-molecular-weight heparins (LMWHs) have been shown to be as safe and effective as intravenous unfractionated heparin (UFH) for the initial treatment of patients with deep vein thrombosis and acute symptomatic pulmonary embolism. In comparison with UFH, LMWHs have a longer half-life, greater bioavailability and more predictable antithrombotic effect when administered in fixed doses, thus obviating the need for laboratory monitoring. It is therefore feasible that LMWH preparations may replace UFH for the treatment of pulmonary embolism in the future. It is recommended that LMWH should be administered for 5-10 days and should overlap with oral anticoagulant therapy by at least 4 days. Surgical pulmonary embolectomy should only be considered in patients with life-threatening pulmonary embolism who have failed to respond during the first 3 h of thrombolytic therapy. The systematic use of vena cava filters is not recommended in patients presumed to be at high risk for pulmonary embolism.