- S Takach Lapner, research fellow and haematologist,
- C Kearon, professor of medicine
- 1Department of Medicine, McMaster University, Hamilton, Ontario, Canada
- Correspondence to: C Kearon, Hamilton Health Sciences, Juravinski Hospital Division, 711 Concession Street, Hamilton, Ontario L8V 1C3, Canada
- Accepted 23 January 2013
Assessment of clinical pre-test probability (CPTP) is the first step in the diagnosis of pulmonary embolism
Combinations of CPTP and test results are usually needed to identify patients who require, and do not require, anticoagulant therapy
Thrombolytic therapy is usually reserved for patients with hypotension and without major risk factors for bleeding
Pulmonary embolism associated with a reversible risk factor is usually treated for three months
Pulmonary embolism associated with active cancer, or a second unprovoked pulmonary embolism, is usually treated indefinitely
The decision to treat an unprovoked pulmonary embolism for three months or indefinitely is sensitive to an individual patient’s preference and risk of bleeding
Pulmonary embolism is one manifestation of venous thromboembolism, the other being deep vein thrombosis. Pulmonary embolism occurs when a deep vein thrombosis breaks free, passes through the right side of the heart, and lodges in the pulmonary arteries. About 90% of pulmonary emboli come from the legs, with most involving the proximal (popliteal or more central) veins. Prevention of pulmonary embolism therefore requires both prevention of venous thromboembolism and effective treatment of deep vein thrombosis when it occurs. There is a wealth of high quality individual studies and meta-analyses to guide the diagnosis and treatment of pulmonary embolism, and we provide an overview and synthesis of that evidence in this review.
Sources and selection criteria
We searched Medline and the Cochrane Collaboration for up to date systematic reviews, meta-analyses, and high quality randomised controlled trials pertaining to the epidemiology, diagnosis, and treatment of pulmonary embolism. We also drew on the recently published guidelines on diagnosis and treatment of pulmonary embolism from the National Institute for Health and Clinical Excellence (NICE) and on treatment for venous thromboembolism from the American College of Chest Physicians.
Why is pulmonary embolism important?
Symptomatic venous thromboembolism occurs in 1–2 per 1000 adults each year, with about a third …