Review Question - QID 106187

The patient's presentation and CT findings suggest an acute pulmonary embolism. Patients with essential thrombocythemia have an increased incidence of clot formation due to chronically elevated platelets, and pulmonary embolism and venous thromboembolism are common. First line treatment is unfractionated heparin (UFH) or a low-molecular weight heparin (LMWH), such as enoxaparin. Overall LMWH has been shown to reduce mortality when compared to UFH, particularly in patients with cancer, as well as patients can be discharged on LMWH as compared to UFH.

Acute anticoagulation should be performed in all cases of pulmonary embolism, as patients are at high risk for recurrent pulmonary embolism if left untreated. Unfractionated heparin and LMWH are the treatments of choice for acute anticoagulation in pulmonary emboli and in venous thromboembolism. Heparin is also an attractive acute anticoagulant because it provides an easy bridge to long-term outpatient anticoagulation therapy on warfarin.

Erkens et al. review treatments for venous thromboembolism. They conclude that compared to UFH, LMWH are more effective and safer. Furthermore, thrombotic complications are reduced with LMWH, as are the incidence of major hemorrhage and overall mortality at follow-up.

The Columbus Investigators explain the benefits of LMWH over UFH in the acute treatment of pulmonary embolism. UFH use is associated with wide anticoagulant responses and frequent laboratory monitoring and dose adjustment; whereas LMWH have longer half-life and more predictable anticoagulation with subcutaneous administration without the need for laboratory monitoring.

Figure A shows a saddle embolus and substantial thrombus burden in the lobar branches of both main pulmonary arteries.

Incorrect Answers:
Answer 1: While coumadin may be used for long-term anticoagulation in patients with thromboembolism, it is not used in the acute setting because therapeutic anticoagulation levels cannot be reached immediately.
Answer 2: An inferior vena cava filter would be the correct answer if the patient was at risk for bleeding such as if they had experienced trauma or surgery recently or if they have a history of a hemorrhagic stroke.
Answer 4: Observation is not appropriate in patients with pulmonary embolism as the risk of recurrence is high.
Answer 5: Dabigatran is a direct thrombin inhibitor. Evidence does not yet support its use in treatment of pulmonary embolism.