Pulmonary Embolism and Deep Vein Thrombosis
“Pulmonary embolism (PE) occurs when clotted blood enters the pulmonary arterial circulation. Most PEs result from deep vein thrombosis (DVT) in the legs, arms, or pelvis and occasionally from the jugular vein or inferior vena cava. The term venous thromboembolism (VTE) includes PE and DVT.”1
“Most guidelines categorize VTE as provoked (or secondary) or unprovoked (idiopathic).
- Provoked VTEs are acquired and often time-limited conditions, generally often following recent surgery, trauma, or any condition associated with limb or body immobility; active cancer is a VTE provoker that often persists.
- Other provoking factors generally include diseases or conditions that impede venous blood flow, infection, chronic disease, estrogen use, pregnancy or initial postpartum interval, and age >50 years (each year after 50 increases the risk).
- Unprovoked VTE patients have no known risk factors, suggesting an increased tendency to clot.”1
Deep Vein Thrombosis
“Patients with DVT complain of extremity pain, swelling, or cramping. A difference of ≥2 cm between right and left leg diameter at 10 cm below the tibial tubercle doubles the likelihood of DVT.”1
Having an approach to the suspected DVT includes recognition of signs and symptoms, risk stratification with appropriate diagnostic tests, and knowing when (and what) treatment is indication. (AIR Series on DVTs) Many presentations can mimic DVTs, therefore always keep a large differential on hand.
“The hallmark of PE is dyspnea unexplained by auscultatory findings, ECG changes, or clear alternative diagnosis on chest radiograph. Chest pain with pleuritic features is the second most common symptom of PE, although about one half of all patients diagnosed with PE in the ED have no complaint of chest pain.”1
A patient with dyspnea can be difficult to work-up, however certain risk stratification tools are available to assist with determining who does and does not require the necessary PE work-up. A summary of these tools in addition to the recommended treatment is provided by EM Cases.
Click HERE for a list of all mentioned FOAM resources.
- Kline, J., Chapter 56, “Venous Thromboembolism”. Tintinalli’s Emergency Medicine – A Comprehensive Study Guide. J Tintinalli. 8th ed. McGraw-Hill Education, 2016.
Prepared by Alex Mungham PGY1 FM – University of Ottawa