Evaluacion de tep

The

new england journal

of

medicine

clinical practice

The Evaluation of Suspected Pulmonary Embolism
Peter F. Fedullo, M.D., and Victor F. Tapson, M.D.
This Journal feature begins with a case vignette highlighting a common clinical problem. Evidence supporting various strategies is then presented, followed by a review of formal guidelines, when they exist. The article ends withthe authors’ clinical recommendations.

An otherwise healthy 51-year-old woman presents to her physician with pleuritic right posterior chest pain, without dyspnea or hemoptysis. Her temperature is 38.2°C, and her pulse is 102 beats per minute. Physical examination discloses a pleural friction rub over the posterior right hemithorax but is otherwise unremarkable. A chest radiograph is normal. Sheis treated with an antiinflammatory agent for presumed viral pleurisy. Three days later, she returns, reporting dyspnea. How should she be evaluated?

the clinical problem
Although the exact incidence of pulmonary embolism is uncertain, it is estimated that 600,000 episodes occur each year in the United States, resulting in 100,000 to 200,000 deaths.1 When the diagnosis of embolism isconfirmed and effective therapy is initiated, recurrence of embolism is rare and death is uncommon — with the exception of patients who initially present with hemodynamic impairment, among whom the mortality rate approaches 20 to 30 percent.2,3 The majority of preventable deaths associated with pulmonary embolism can be ascribed to a missed diagnosis rather than to a failure of existing therapies. Thediagnosis of pulmonary embolism is confounded by a clinical presentation that may be subtle, atypical, or obscured by another coexisting disease.4 Several noninvasive diagnostic techniques have been developed to improve the accuracy of diagnosis and limit the number of patients who require angiography, a procedure that is associated with some risk and is underutilized in traditional diagnosticstrategies.5,6 However, no single noninvasive diagnostic test is sufficiently sensitive or specific for the diagnosis in all patients.
From the Division of Pulmonary and Critical Care Medicine, University of California, San Diego, Medical Center, San Diego (P.F.F.); and the Division of Pulmonary and Critical Care Medicine, Duke University Medical Center, Durham, N.C. (V.F.T.). Address reprint requeststo Dr. Fedullo at the Division of Pulmonary and Critical Care Medicine, University of California, San Diego, Medical Center, 9300 Campus Point Dr., MC 7381, La Jolla, CA 92037-1300, or at pfedullo@uscb.edu. N Engl J Med 2003;349:1247-56.
Copyright © 2003 Massachusetts Medical Society.

strategies and evidence
clinical diagnosis

The clinical presentation and routinely available laboratorydata, such as results on electrocardiography, chest radiography, and analysis of arterial blood gases, cannot be relied on to confirm or rule out pulmonary embolism. Although symptoms and signs such as dyspnea, pleuritic chest pain, tachypnea, and tachycardia can raise the suspicion of embolism and indicate a need for further evaluation, these findings are inconsistent in patients with embolism andare nonspecific.4,7 The presence of one or more risk factors for venous thromboembolism (Table 1) may lower the threshold for the consideration of a diagnostic evaluation. As a means of providing an objective basis for the clinical assessment of the probability of embolism, several sets of standardized prediction rules have been evaluated and published; these range widely in complexity.8-11 Simplepre-

n engl j med 349;13

www.nejm.org

september 25, 2003

1247

Downloaded from www.nejm.org by ERNESTO LPEZ GALICIA on September 7, 2005 . Copyright © 2003 Massachusetts Medical Society. All rights reserved.

The

new england journal

of

medicine

Table 1. Risk Factors for Venous Thromboembolism. Age >40 yr History of venous thromboembolism Surgery requiring >30 min of...