What is a pulmonary embolism?
A pulmonary embolism is a blood clot in the lung that occurs when a clot in another part of the body (often the leg or arm) moves through the bloodstream and becomes lodged in the blood vessels of the lung. This restricts blood flow to the lungs, lowers oxygen levels in the lungs and increases blood pressure in the pulmonary arteries.
If a clot develops in a vein and it stays there, it’s called a thrombus. If the clot detaches from the wall of the vein and travels to another part of your body, it’s called an embolus.
If PEs are not treated quickly, they can cause heart or lung damage and even death.
Who is at risk of developing a blood clot?
People at risk for developing a blood clot are those who:
- Have been inactive or immobile for long periods of time due to bed rest or surgery.
- Have a personal or family history of a blood clotting disorder, such as deep vein thrombosis (DVT) or pulmonary embolism (PE).
- Have a history of cancer or are receiving chemotherapy.
- Sit for prolonged periods.
People at risk for developing a pulmonary embolism include those who:
- Are inactive for long periods of time while traveling via motor vehicle, train or plane.
- Have a history of heart failure or stroke.
- Are overweight or obese.
- Have recently had trauma or injury to a vein, possibly after a recent surgery, fracture or due to varicose veins.
- Are pregnant or have given birth in the previous 6 weeks.
- Are taking birth control pills (oral contraceptives) or hormone replacement therapy.
- Placement of central venous catheters through the arm or leg If you have any of these risk factors and you have had a blood clot, please talk with your health care provider so steps can be taken to reduce your personal risk.
How serious is a pulmonary embolism?
A pulmonary embolism may dissolve on its own; it is seldom fatal when diagnosed and treated properly. However, if left untreated, it can be serious, leading to other medical complications, including death. A pulmonary embolism can:
- Cause heart damage.
- Be life-threatening, depending on the size of the clot.
Symptoms and Causes
What are the symptoms of pulmonary embolism?
Symptoms of pulmonary embolism vary, depending on the severity of the clot. Although most people with a pulmonary embolism experience symptoms, some will not. The first signs are usually shortness of breath and chest pains that get worse if you exert yourself. You may cough up bloody sputum. If you have these symptoms get medical attention right away. Pulmonary embolism is serious but very treatable. Quick treatment greatly reduces the chance of death.
Symptoms may include:
- Sudden shortness of breath -- whether you’ve been active or at rest.
- Unexplained sharp pain in your chest, arm, shoulder, neck or jaw. The pain may also be similar to symptoms of a heart attack.
- Cough with or without bloody sputum (mucus).
- Pale, clammy or bluish-colored skin.
- Rapid heartbeat (pulse).
- Excessive sweating.
- In some cases, feeling anxious, light-headed, faint or passing out.
It is also possible to have a blood clot and not have any symptoms, so discuss your risk factors with your health care provider.
If you have any symptoms of pulmonary embolism, get medical attention immediately.
What causes pulmonary embolism?
Pulmonary embolism may occur:
- When blood collects (or “pools”) in a certain part of the body (usually an arm or leg). Pooling of blood usually occurs after long periods of inactivity, such as after surgery or bed rest.
- When veins have been injured, such as from a fracture or surgery (especially in the pelvis, hip, knee or leg).
- As a result of another medical condition, such as cardiovascular disease (including congestive heart failure, atrial fibrillation and heart attack) or stroke.
- When clotting factors in the blood are increased, elevated, or in some cases, lowered. Elevated clotting factors can occur with some types of cancer or in some women taking hormone replacement therapy or birth control pills. Abnormal or low clotting factors may also occur as a result of hereditary conditions.
Diagnosis and Tests
How is a pulmonary embolism detected?
Pulmonary embolism is commonly detected through the following tests:
- Computed tomography (CT) scan.
- Lung scan.
- Blood tests (including the D-dimer test).
- Pulmonary angiogram.
- Ultrasound of the leg -- helps to identify blood clots in patients who cannot have an X-ray due to dye allergies or who are too sick to leave their hospital room.
- Magnetic resonance imaging (MRI) of the legs or lungs.
Management and Treatment
How is pulmonary embolism treated?
Treatment for pulmonary embolism is typically provided in a hospital, where your condition can be closely monitored.
The length of your treatment and hospital stay will vary, depending on the severity of the clot.
Depending on your medical condition, treatment options may include anticoagulant (blood-thinner) medications, thrombolytic therapy, compression stockings, and sometimes surgery or interventional procedures to improve blood flow and reduce the risk of future blood clots.
In most cases, treatment consists of anti- coagulant medications (also called blood thinners). Anticoagulants decrease the blood’s ability to clot and prevent future blood clots.
Anticoagulant medications include warfarin (Coumadin®), heparin, low-molecular weight heparin (such as Lovenox® or Dalteparin®) and fondaparinux (Arixtra®).
- Warfarin comes in tablet form and is taken orally (by mouth).
- Heparin is a liquid medication and is given either through an intravenous (IV) line that delivers medication directly into the vein, or by subcutaneous (under the skin) injections given in the hospital.
- Low molecular-weight heparin is injected beneath or under the skin (subcutaneously). It is given once or twice a day and can be taken at home.
- Fondaparinux (Arixtra) is a new medication that is injected subcutaneously, once a day.
You and your family will receive more information about how to take the anticoagulant medication that is prescribed. As with any medication, it’s important that you understand how and when to take your anticoagulant and to follow your doctor’s guidelines.
The type of medication you were prescribed, how long you need to take it, and the type of follow-up monitoring you’ll need depends on your diagnosis. Be sure to keep all scheduled follow-up appointments with your doctor and the laboratory so your response to the medication can be monitored closely.
While taking anticoagulants, your follow-up will include frequent blood tests, such as:
- PT-INR: The Prothrombin time (PT or protime)/ International Normalized Ratio (INR) test: Your INR will help your health care provider determine how fast your blood is clotting and whether your medication dose needs to be changed. This test is used to monitor your condition if you are taking Coumadin.
- Activated partial thromboplastin (aPTT): Measures the time it takes blood to clot. This test is used to monitor your condition if you are taking heparin.
- Anti-Xa or Heparin assay: Measures the level of low molecular-weight heparin in the blood. It is usually not necessary to use this test unless you are overweight, have kidney disease or are pregnant.
What are other treatment options?
Compression stockings (support hose) aid blood flow in the legs and should be used as prescribed by your doctor. The stockings are usually knee- high length and compress your legs to prevent the pooling of blood.
Talk with your doctor about how to use your compression stockings, for how long, and how to care for them. It is important to launder compression stockings according to directions to prevent damaging them.
If a pulmonary embolism is life-threatening, or if other treatments aren’t effective, your doctor may recommend:
- Surgery to remove the embolus from the pulmonary artery.
- An interventional procedure in which a filter is placed inside the body’s largest vein (vena cava filter) so clots can be trapped before they enter the lungs.
Thrombolytic medications (“clot busters”), including tissue plasminogen activator (TPA), are used to dissolve the clot. Thrombolytics are always given in a hospital where the patient can be closely monitored. These medications are used in special situations, such as if the patient’s blood pressure is low or if the patient’s condition is unstable due to the pulmonary embolism.
How do I prevent pulmonary embolism?
- Exercise regularly. If you can’t walk around due to bed rest, recovery from surgery or extended travel, move your arms, legs and feet for a few minutes each hour. If you know you will need to sit or stand for long periods, wear compression stockings to encourage blood flow.
- Drink plenty of fluids, like water and juice, but avoid excess alcohol and caffeine.
- If you need to be stationary for long periods of time, move around for a few minutes each hour: move your feet and legs, bend your knees, and stand on tip-toe.
- Do not smoke.
- Avoid crossing your legs.
- Do not wear tight-fitting clothing.
- Lose weight if you are overweight.
- Elevate your feet for 30 minutes twice a day.
- Talk to your doctor about reducing your risk factors, especially if you or any of your family members have experienced a blood clot.
What is follow-up care after a pulmonary embolism?
Be sure you discuss and understand your follow- up care with your doctor. Follow your doctor’s recommendations to reduce the risk of another pulmonary embolism.
Keep all appointments with your doctor and the laboratory so your response to prescribed treatments can be monitored.