lung and airway disorders
Pulmonary Embolism (PE)
Introduction
Pulmonary embolism is the blocking of an artery of the lung (pulmonary artery) by a collection of solid material brought through the bloodstream (embolus)—usually a blood clot (thrombus) or rarely other material. Pulmonary embolism is usually caused by a blood clot, although other substances can also form emboli and block an artery. Symptoms of pulmonary embolism vary but usually include shortness of breath. Doctors often diagnose pulmonary embolism by looking for blockage of a pulmonary artery using computed tomography (CT) angiography or lung scanning. To treat pulmonary embolism, anticoagulant medications are used to thin the blood and keep emboli from enlarging while the body dissolves the clots; other measures (such as medications or physical measures to break up blood clots or surgery) may be needed for people who appear to be at risk of dying. To prevent pulmonary embolism, anticoagulant medications (sometimes called blood thinners) can be given to people at high risk. The pulmonary arteries carry blood from the right side of the heart to the lungs. The blood picks up oxygen from the lungs and travels back to the left side of the heart. From the left side of the heart, the blood is pumped to the rest of the body to Exchanging Oxygen and Carbon Dioxide . The blood then returns to the right side of the heart in the veins. When a pulmonary artery is blocked by an embolus, people may not be able to get sufficient oxygen into the blood. Large emboli (massive, or high-risk pulmonary emboli) cause so much blockage that the right side of the heart cannot pump enough blood through the pulmonary arteries, and the blood pressure decreases. If too little blood is pumped or the heart is strained excessively, the person can go into Shock and die. Sometimes, the blockage of blood flow causes part of the lung tissue to die, which is called a The body usually breaks up small clots more quickly than larger clots, keeping damage to a minimum. Large clots take longer to disintegrate. For unknown reasons, in a small percentage of people, the clots do not break up and form scars, which may cause a chronic increase of blood pressure in the pulmonary arteries ( Pulmonary Hypertension ) and cause long-term symptoms, including shortness of breath and edema (or swelling) of the lower extremities. Pulmonary embolism affects about 350,000 people per year and causes 85,000 deaths per year in the United States. It affects mainly adults. 