Symptoms of Pulmonary Embolism
Pulmonary emboli may produce sudden and severe shortness of breath, rapid breathing, and chest pain. Massive emboli, which often result in death within a few minutes, may also be accompanied by a feeling of impending doom, profuse sweating, loss of consciousness, shock, and a bluish color in the lips and fingertips.
Peripheral emboli, which also occur abruptly and without warning, are associated with chest pain, shortness of breath, and, later, coughing up blood. People with multiple small emboli may have no symptoms for many months until they develop right heart failure, which can cause fatigue, swelling of the ankles, weight loss, and shortness of breath.
DVT can cause pain and swelling in the affected body part, and the area may be tender and hot to the touch. However, because the condition usually occurs deep within the leg, about half the time there are no signs or symptoms. Often, DVT is discovered only when a physician looks for it in someone who is at high risk for it.
Pulmonary Embolism Diagnosis
Although a doctor may suspect the presence of pulmonary embolism when symptoms occur in someone with typical signs of DVT, often there is not enough evidence to make a definitive diagnosis. Experts now agree that a spiral computed tomography (CT) scan with contrast dye injection is the most effective noninvasive test for pulmonary embolism. Studies suggest that this test can accurately diagnose large and medium-sized pulmonary emboli but not very small ones.
Previously, the most common diagnostic test was an angiogram of the pulmonary arteriesan x-ray following the injection of a contrast material into the pulmonary artery. But this invasive test is being used less frequently, because the spiral CT is most often accurate enough to guide therapy reliably. New research indicates that extending a chest CT scan to include the legs can help doctors more accurately diagnose a pulmonary embolism.
Pulmonary Embolism Prevention
The only effective way to prevent pulmonary emboli is to prevent DVT from arising in the first place and to be sure it is recognized and treated vigorously if it does occur. Steps to prevent DVT include taking frequent walks when flying or riding on a long trip, getting out of bed as soon as possible after surgery, and using anticoagulants and other therapies (for example, pneumatic compression stockings) when possible if you are bedridden or have had an operation. Studies show that wearing compression stockings on long airplane trips can reduce the risk of blood clots by more than 90 percent.
People with a family history of DVT should take special precautions, because they may have inherited an abnormal tendency for their blood to clot. Individuals who have had DVT in the past are at increased risk for a recurrence.
Treatment for Pulmonary Embolism
Supportive treatment for an individual with a large pulmonary embolus includes pain relief and oxygen. Thrombolytic (clot-busting) drugs may dissolve the clot and restore blood flow through the blocked pulmonary artery. However, surgical removal of the blood clot may be required in individuals with a large, life-threatening clot or in those whose condition deteriorates during medical treatment. Thrombolytic therapy and surgery are generally reserved for people with massive clots and shock.
Most of the time, people with a pulmonary embolus are treated with anticoagulantsheparin and warfarin (Coumadin) in both the short and long term. Intravenous heparin is started immediately and continued for at least three to five days, and oral warfarin is continued for three to six months (with close monitoring).
Unfortunately, anticoagulants are not effective for the prevention of further emboli in some people and can be dangerous in people who are at high risk for bleeding in the head (people with a brain aneurysm, for example) or people with active gastrointestinal bleeding.
In these instances, a sieve-like filtering device may be placed in the inferior vena cava (the vein that returns blood from the lower body to the heart) to prevent blood clots from entering the heart and lungs. Although filters reduce the immediate risk of having an embolus lodge in the lungs, they do not reduce the long-term risk of developing pulmonary emboli at a later time. Consequently, continued use of anticoagulants is imperative, because clots can still reach the lungs through new, collateral blood vessels that slowly develop around the filter.