Pulmonary embolism (PE) is a blockage of an artery in the lungs by a substance that has moved from elsewhere in the body through the bloodstream (embolism). Symptoms of a PE may include shortness of breath, chest pain particularly upon breathing in, and coughing up blood. Symptoms of a blood clot in the leg may also be present, such as a red, warm, swollen, and painful leg. Signs of a PE include low blood oxygen levels, rapid breathing, rapid heart rate, and sometimes a mild fever. Severe cases can lead to passing out, abnormally low blood pressure, obstructive shock, and sudden death.PE usually results from a blood clot in the leg that travels to the lung. The risk of blood clots is increased by cancer, prolonged bed rest, smoking, stroke, certain genetic conditions, estrogen-based medication, pregnancy, obesity, and after some types of surgery. A small proportion of cases are due to the embolization of air, fat, or amniotic fluid. Diagnosis is based on signs and symptoms in combination with test results. If the risk is low, a blood test known as a D-dimer may rule out the condition. Otherwise, a CT pulmonary angiography, lung ventilation/perfusion scan, or ultrasound of the legs may confirm the diagnosis. Together, deep vein thrombosis and PE are known as venous thromboembolism (VTE).Efforts to prevent PE include beginning to move as soon as possible after surgery, lower leg exercises during periods of sitting, and the use of blood thinners after some types of surgery.
The long-term safety profile of permanently leaving a filter inside the body is not known. Surgery
Surgical management of acute pulmonary embolism (pulmonary thrombectomy) is uncommon and has largely been abandoned because of poor long-term outcomes. However, recently, it has gone through a resurgence with the revision of the surgical technique and is thought to benefit certain people. Chronic pulmonary embolism leading to pulmonary hypertension (known as chronic thromboembolic hypertension) is treated with a surgical procedure known as a pulmonary thromboendarterectomy. Epidemiology
There are roughly 10 million cases of pulmonary embolisms per year. In the United States, pulmonary embolisms are the primary cause of at least 10,000 to 12,000 deaths per year and a contributing cause in at least 30,000 to 40,000 deaths per year. True incidence involving pulmonary embolisms is unknown because they often go undiagnosed or unnoticed until autopsy. From 1993 to 2012, there have been an increased number of admissions in hospitals due to pulmonary embolisms, jumping from 23 cases per 100,000 people to 65 cases per 100,000 people. Despite this increase, there has been a decrease in mortality during that same time period due to medical advances that have occurred.Venous thromboembolism (VTE), a common risk factor, is present at much higher rates in those over the age of 70 (three times higher compared to those aged 45 to 69). This is likely due to there being a generally lower level of activity among the elderly, resulting in higher rates of immobility and obesity. VTE has a large, and continuously rising, case fatality rate.