Pulmonary thrombosis is a serious medical condition in which a blood clot, or thrombus, is obstructing a blood vessel in a lung. It differs slightly from other types of thrombosis and might be caused by other thrombosis conditions, such as air bubbles, part of a tumor, fat from the marrow of a broken bone, or, more commonly, deep vein thrombosis. Deep vein thrombosis refers to blood clots that commonly affect the large veins of the legs and that might travel to a lung and cause a pulmonary embolism. Symptoms of pulmonary thrombosis vary greatly, but the most common symptoms include unexplained shortness of breath, chest pain that worsens with movement and coughing up blood or bloody sputum.
The lungs contain tiny air sacs called alveoli. The alveioli sacs are separated by thin membranes from which run a network of tiny, blood-rich capillaries. The capillaries absorb molecules of oxygen and carbon dioxide and pass them into the bloodstream through the circulatory system. Small veins within the lungs feed the waste product of respiration, carbon dioxide, into the lungs to be exhaled out of the body. The smooth transition of oxygenated blood into the lungs and carbon dioxide out of the lungs is called respiration.
A blood clot that forms within a vein or artery in the lung blocks the exchange of oxygen and carbon dioxide. The patient might experience the common signs of pulmonary vein thrombosis or might suffer from other symptoms of pulmonary thrombosis, such as wheezing, bluish-colored skin and rapid or irregular heartbeat. The patient also might have a faint pulse or experience a lightheaded feeling or excessive sweating. Pulmonary thrombosis is a life-threatening condition that requires emergency medical attention. Bloody sputum and chest pain are critical symptoms of pulmonary thrombosis and should not be ignored.
Medical professionals use a series of tests to diagnose pulmonary thrombosis. A chest X-ray of the heart and lungs is the first general procedure. Although X-rays do not show the symptoms of pulmonary thrombosis, this tests allows doctors to check for and possibly rule out any other medical conditions. A ventilation-perfusion scan infuses a small amount of radioactive material into the lungs and the bloodstream via injection. Other tests include a spiral computerized tomography X-ray scan that takes three-dimensional helical snapshots of the body, a pulmonary angiogram in which injected dye is monitored as it circulates throughout the body, an ultrasound scan and magnetic resonance imaging (MRI) tests.
Treating pulmonary vein thrombosis depends on the severity of the condition and the physical condition of the patient. Anticoagulants that thin the blood and clot-dissolving thrombolytics are administered, but they can cause severe bleeding. Extreme cases might require surgery to remove the clot. A vein filter inserted via a catheter from the leg to the inferior vena cava of the heart might prevent clots from being carried into the lungs.
The best method for preventing pulmonary vein thrombosis is physical exercise. Medical professionals recommend that patients avoid sitting for long periods of time without activity. Compression stockings and pneumatic compression squeeze the legs to improve blood flow and might prevent the formation of deep vein thrombosis. For patients who require surgery, anticoagulants often are administered as a preventative measure if there is a risk of pulmonary vein thrombosis.