Acute pulmonary embolism (PE) is a common and often fatal disease. Mortality can be reduced by prompt diagnosis and therapy. Unfortunately, the clinical presentation of PE is variable and nonspecific; thus, diagnostic testing is necessary before confirming or excluding the diagnosis of PE.
Diagnosis of PE is discussed in detail here. The epidemiology, prognosis, pathophysiology, risk factors, symptoms, and signs of PE are reviewed elsewhere. In addition, the treatment of PE is discussed separately. (See "Overview of acute pulmonary embolism" and "Treatment of acute pulmonary embolism" and "Fibrinolytic (thrombolytic) therapy in acute pulmonary embolism and lower extremity deep vein thrombosis".)
Clinical impression tends to be nonspecific for acute PE because many of the symptoms and signs of acute PE are common among patients without PE (table 1). This was demonstrated by a meta-analysis of 19 studies (25,343 patients), which found that clinical impression alone has a sensitivity and specificity of 85 and 51 percent, respectively, for acute PE . This emphasizes the need for additional diagnostic evaluation whenever acute PE is suspected.
In this section, we summarize the major diagnostic tests employed in the evaluation of patients with suspected PE. Our recommended diagnostic approach is described in the following section. (See 'Our approach' below.)
Laboratory — Routine laboratory findings are nonspecific. They include leukocytosis, an increased erythrocyte sedimentation rate (ESR), and an elevated serum LDH or AST (SGOT) with a normal serum bilirubin.