Current opinion in pulmonary medicine
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Review Comparative Study
External validation and comparison of recently described prediction rules for suspected pulmonary embolism.
The assessment of pretest probability, allowing the categorization of patients clinically suspected of having pulmonary embolism in low, intermediate, and high clinical probability, is an essential step in contemporary diagnostic strategies because it permits limiting the number of additional diagnostic tests, especially invasive tests. Clinical probability can be evaluated implicitly or by prediction rules. Two prediction rules for pulmonary embolism have been described: the Canadian prediction rule (the Wells score) and the Geneva prediction rule. Their original descriptions were published in 2000 and 2001, respectively. These prediction rules need to be externally validated, and, ideally, outcome studies should demonstrate that patients may be safely treated on the basis of the assessment of the clinical probability they provide. Therefore, the purpose of this review is to discuss the external validation of these rules, because this particular point has been only recently achieved. ⋯ Studies comparing an empiric assessment with explicit assessment, such as the Wells simplified score or the Geneva score, have shown that the three tools show similar accuracy. External validation and use of both rules in prospective management studies have only recently been performed and have confirmed their validity. Some reports suggest that empiric assessment may be influenced by level of training. Objective prediction rules seems to be less influenced by experience and should be preferred by more junior doctors. The tool used for clinical probability assessment is probably less important than the principle of a careful clinical probability assessment in each patient with suspected pulmonary embolism.
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Review
Pentasaccharides in the prophylaxis and treatment of venous thromboembolism: a systematic review.
The aim of this review is to perform a critical analysis of all completed studies evaluating pentasaccharides-synthetically derived, selective inhibitors of activated factor X-in prophylaxis in major orthopedic surgery and the treatment of venous thromboembolism. ⋯ Fondaparinux, one of the first of a new class of synthetic selective factor Xa inhibitors, is overall 50% more effective in reducing venous thromboembolism than enoxaparin in major orthopedic surgery, with an overall 1% increased rate of major bleeding, when compared with enoxaparin. The incidence of fatal bleeding, critical organ bleeding, or bleeding leading to reoperation did not differ significantly between the two treatment groups. Fondaparinux is equally effective as low molecular weight heparins and unfractionated heparin in the initial treatment of patients with proximal vein thrombosis and pulmonary embolism, respectively. Finally, as with any new drug, fondaparinux should be used cautiously and only in patients who reflect the population of the clinical trials in which the drug was evaluated.
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Hypersensitivity pneumonitis (HP), also known as extrinsic allergic alveolitis, is a granulomatous, inflammatory disease of the lungs caused by the inhalation of antigenic organic particles or fumes. The disease may present as an acute, subacute, or chronic illness. Episodes of acute and subacute HP usually resolve following cessation of antigen exposure. Chronic HP may be progressive, irreversible, and result in debilitating fibrotic lung disease. This review discusses current concepts regarding the diagnosis, pathogenesis, and treatment of HP. ⋯ A careful environmental and occupational history and establishment of exposure to a known inciting antigen are key factors in making the diagnosis of HP. Serum precipitating antibodies, bronchoalveolar lavage, and lung biopsy may be helpful in making the diagnosis. Avoidance of organic antigen exposure is the most important factor in the management of HP. Corticosteroids are indicated for the treatment of severe acute and subacute HP and for chronic HP that is severe or progressive. Long-term corticosteroid therapy for the treatment of chronic HP should be considered only if objective improvement in clinical signs, pulmonary function, or radiographic abnormalities is documented.