Pulmonary embolism

Pulmonary embolism (PE) is a potentially life-threatening condition typically resulting from dislodged thrombus occluding the pulmonary arteries. Right heart failure and cardiac arrest may ensue if not aggressively treated.

Patients who develop PE commonly have thromboembolic risk factors, such as cancer, trauma, major surgery, hospitalization, immobilization, pregnancy, or oral contraceptive use. PE may also be unprovoked (idiopathic), occurring in the absence of any identifiable extrinsic risk factors.

Symptoms include chest pain (especially with a deep breath), dyspnea, and a sense of apprehension. Hemoptysis and syncope are less common; the latter is strongly associated with increased clot burden.

PE is definitively confirmed by an imaging study, most commonly computed tomography pulmonary angiogram (CTPA). Diagnostic algorithms that include assessment of the likelihood of PE being present should be used to optimize the number of patients undergoing an imaging study.

Most patients with PE are successfully treated with anticoagulant therapy. Low-risk patients may be treated without hospitalization.

Hemodynamically unstable patients (those considered to have PE with a high risk for mortality) require urgent primary reperfusion in conjunction with anticoagulation and supportive care.

At least 3 months of anticoagulant therapy is required for all patients with PE. Continued anticoagulant therapy for secondary prevention is indicated in selected patients.

Pulmonary embolism (PE) is a consequence of thrombus formation within a deep vein of the body, most frequently in the lower extremities. Thrombus formation in the venous system occurs as a result of venous stasis, trauma, and hypercoagulability. These factors are collectively known as Virchow triad.[1]Cervantes J, Rojas G. Virchow's legacy: deep vein thrombosis and pulmonary embolism. World J Surg. 2005;29 Suppl 1:S30-4. http://www.ncbi.nlm.nih.gov/pubmed/15818472?tool=bestpractice.com Approximately 51% of deep venous thrombi will embolize to the pulmonary vasculature, resulting in a PE.[2]Huisman MV, Büller HR, ten Cate JW, et al. Unexpected high prevalence of silent pulmonary embolism in patients with deep venous thrombosis. Chest. 1989 Mar;95(3):498-502. http://www.ncbi.nlm.nih.gov/pubmed/2920574?tool=bestpractice.com Venous thromboembolic disease is the preferred term to describe the spectrum of disease beginning with the risk factors of Virchow triad, progressing to deep venous thrombosis, and resulting in life-threatening PE.