The arterial blood (oxygen-rich blood) supply to the lungs via the pulmonary artery or one of its branches can be blocked by matter such as a blood clot (most common), fat, air, tumor (abnormal growth) tissue, bone marrow, amniotic fluid (fluid in the womb), or foreign substances. This is called a pulmonary embolus (plural emboli).
Sudden onset
One or multiple symptoms
Cough -- may be blood-tinged
Shortness of breath
Chest pain may be worse with breathing or coughing
Pain may be on one side and may worsen with bending forward.
Deep Vein Thrombosis (DVT) -- blood clots or thrombi sometimes form in the leg veins (carrying oxygen-poor blood) and occasionally dislodge (embolize) from the walls of the veins, traveling through the blood stream into the right side of the heart, then to the pulmonary artery, where they block the blood supply to that particular section of the lung. This section of lung then undergoes an infarction (i.e., it dies).
Emboli can also arise from clots in the right side of the heart.
Pieces of tumors invading the circulatory system, fat, air, and other foreign substances can also enter the blood stream and block the arteries supplying different sections (i.e., 5 lobes) of the lungs.
Hypercoagulability -- increased tendency for clot formation is seen in certain conditions and with certain medications and drugs.
Other blood tests may be normal, but levels of Antithrombin III (measures risk for clot formation) may provide valuable information.
Chest X-Ray may be normal or may show wedge-shaped area, one-sided elevation of the diaphragm (muscle that helps lungs in breathing), fluids, or collapse.
Electrocardiogram (ECG) (records the electrical activities of the heart) may show characteristic patterns.
To find the source of the clot or infarcted area in the lungs, the following tests may be performed:
Pulmonary (lung) scanning or ventilation/perfusion scan (V/Q scan) will show the infarcted segment.
Angiography-injection of a dye into arterial supply will identify the location of the blockage.
Echocardiography-sound used to find the clot in the heart.
Spiral CAT scan-computer generates picture
Venous duplex scanning, impedance plethysmography, and Doppler Ultrasound-look for clots inside the veins (legs, thighs, etc).
Hospitalization
Depends on the severity
Bed rest
Administer oxygen or fluids as needed
Pain medication if needed
Attempt to dissolve the clot (thrombolysis) and prevent further clot formation with intravenous (inside the veins) use of Heparin and Warfarin (pill form).
Potent clot busters such as Streptokinase, Urokinase, and TPA are also beneficial but less available and more expensive.
In patients unable to receive thrombolytic therapy or are doing very poorly surgical, removal of the embolus (embolectomy) may be beneficial.
Some patients with repeated emboli to the lungs or those who cannot take anticoagulants (clot busters) may need a surgical procedure to place an umbrella-like filter in the inferior vena cava (major vein to the heart) to catch the incoming clots.
Call 911. Avoid prolonged bed rest, exercise regularly, walk often during long air flights, and avoid smoking while on estrogen-containing drugs.
