A pulmonary embolism (PE) is a sudden blockage of the arteries leading to the lung . The blockage is usually the result of a blood clot that traveled to the lung from a vein in the leg as the result of a condition called deep vein thrombosis (DVT).
- Pulmonary embolism can be fatal if the the blood clot is large, or if there are multiple clots.
- The people at greatest risk of developing pulmonary embolism are those who have deep vein thromboses (DVT) or who have had PE before.
- There are a variety of treatment options for pulmonary embolism (PE), including medication, medical procedures, and surgery. The main goals of treating pulmonary embolism is to stop the blood clot from getting bigger and keep new clots from forming. The recommended treatment depends primarily on the severity of symptoms, the risk of recurrence and the age of the patient.
- Preventing DVTs is a key step to preventing pulmonary embolism. Knowing whether you're at risk for developing DVTs and taking steps to lower your risk are important.
- Pulmonary embolism is usually treated in a hospital. After leaving the hospital, you may need to take medicine at home for 6 months or longer to prevent a recurrence.
- Contact your doctor right away if you have any signs or symptoms of pulmonary embolism or DVT.
At least 100,000 cases of pulmonary embolism occur each year in the U.S. PE is the 3rd most common cause of death in hospitalized patients. If left untreated, about 30% of patients who have pulmonary embolism will die. Most of those who die do so within the first few hours of the event.
What Causes Pulmonary Embolism?
In 9 out of 10 cases, pulmonary embolism (PE) begins as a blood clot in the deep veins of the leg due to a condition known as deep vein thrombosis (DVT). The clot breaks free from the vein and travels through the bloodstream to the lungs, where it can block an artery.
Clots in the legs can form if blood flow is restricted and slows down. This can happen when you don't move around for long periods, such as:
- After some types of surgeries
- During a long trip in a car or on an airplane
- If you must stay in bed for an extended time
Veins damaged from surgery or injured in other ways are more prone to blood clots.
Rarely, an air bubble, part of a tumor, or other tissue travels to the lungs and cause a pulmonary embolism. Also, when a large bone in the body (such as the thigh bone) breaks, fat from the marrow inside the bone can travel through the blood to the lungs and cause a PE.
Who Is At Risk for Pulmonary Embolism?
Pulmonary embolism (PE) occurs equally in men and women. The risk increases with age. For every 10 years after age 60, the risk of having PE doubles.
Certain inherited conditions, such as factor V Leiden, increase the risk of blood clotting and PE.
Major Risk Factors
Your risk for PE is high if you have deep vein thrombosis (DVT) or a history of DVT. In DVT, blood clots form in the deep veins of the body—most often in the legs. These clots can break free, travel through the bloodstream to the lungs, and block an artery.
Your risk for PE also is high if you've had the condition before.
Other Risk Factors
Other factors also can increase the risk for PE, such as:
- Being bedridden or unable to move around much
- Having surgery or breaking a bone (the risk goes up in the weeks following the surgery or injury)
- Having certain diseases or conditions, such as a stroke, paralysis (an inability to move), chronic heart disease, or high blood pressure
People who have recently been treated for cancer or who have a central venous catheter are more likely to develop DVT, which increases their risk for PE. A central venous catheter is a tube placed in a vein to allow easy access to the bloodstream for medical treatment.
Other risk factors for DVT include sitting for long periods (such as during long car or airplane rides), pregnancy and the 6-week period after pregnancy, and being overweight or obese. Women who take hormone therapy pills or birth control pills also are at increased risk for DVT.
The risk of developing blood clots increases as your number of risk factors increases.
What Are the Signs and Symptoms of Pulmonary Embolism?
Signs and symptoms of pulmonary embolis) include unexplained shortness of breath, problems breathing, chest pain, coughing, or coughing up blood. A heart arrhythmia (an irregular heartbeat) also may indicate a pulmonary embolism In some cases, the only signs and symptoms are related to deep vein thrombosis (DVT). These include swelling of the leg or along the vein in the leg, pain or tenderness in the leg, a feeling of increased warmth in the area of the leg that's swollen or tender, and red or discolored skin on the affected leg. See your doctor at once if you have any symptoms of PE or DVT.
Some people with pulmonary embolism have no other signs nor symptoms.
Other Signs and Symptoms
Some people who have PE have feelings of anxiety or dread, light-headedness or fainting, rapid breathing, sweating, or an increased heart rate.
How Is Pulmonary Embolism Diagnosed?
To diagnose a pulmonary emboism, your doctor will ask about your medical history and perform a physical exam to look for signs of PE and DVT.
A number of diagnostic tests may be ordered to help diagnose pulmonary embolism.
Doctors use ultrasound to look for blood clots in your legs. A hand-held device called a transducer is placed on the leg and moved back and forth over the affected area. The transducer gives off ultrasound waves and detects their echoes after they bounce off the vein walls and blood cells.
A computer then turns the echoes into a picture on a computer screen, allowing your doctor to see the blood flow in your leg. If blood clots are found in the deep veins of your legs, your doctor will recommend treatment.
Computed Tomography (CT) Scans
Computed tomography is used to look for blood clots in your lungs and in your legs. Dye is injected into a vein in your arm. The dye makes the blood vessels in your lungs and legs show up on an x-ray image. While you lie on a table, an x-ray tube rotates around you, taking pictures from different angles. This test allows doctors to detect most cases of PE. The test only takes a few minutes. Results are available shortly after the scan is completed.
Lung Ventilation/Perfusion Scan (VQ Scan)
A lung ventilation/perfusion scan uses a radioactive substance to show how well oxygen and blood are flowing to all areas of the lungs. This test is very sensitive for diagnosing PE.
Pulmonary angiography is another test used to diagnose PE. A flexible tube called a catheter is threaded through the groin (upper thigh) or arm to the blood vessels in the lungs. Dye is injected into the blood vessels through the catheter. X-ray pictures are taken to show blood flowing through the blood vessels in the lungs. If a blood clot is found, your doctor may use the catheter to extract it or deliver medicine to dissolve it.
Pulmonary angiography is not available at all hospitals, and a trained specialist must perform the test.
Certain blood tests may help your doctor find out whether you're likely to have PE.
A D-dimer test measures a substance in the blood that's released when a clot breaks up. High levels of the substance may mean there's a clot. If your test is normal and you have few risk factors, PE isn't likely.
Other blood tests check for inherited disorders that cause clots and measure the amount of oxygen and carbon dioxide in your blood. A clot in a blood vessel in your lungs may lower the level of oxygen in your blood.
To rule out other possible causes of your symptoms, your doctor may use one or more of the following tests.
- Echocardiogram. An echocardiogram (ECHO) uses sound waves to check heart function and to detect blood clots inside the heart.
- EKG (electrocardiogram). An EKG measures the rate and regularity of your heartbeat.
- Chest x-ray. A chest x-ray provides a picture of your lungs, heart, large arteries, ribs, and diaphragm (the muscle below your lungs).
- Chest MRI (magnetic resonance imaging). This test uses radio waves and magnetic fields to make pictures of organs and structures inside the body. In many cases, an MRI can provide information that can't be seen on an x ray.
Treatment Options for Pulmonary Embolism (PE)
Pulmonary embolism (PE) is treated with medicines, procedures, and other therapies. The main goals of treating PE are to stop the blood clot from getting bigger and keep new clots from forming. Treatment may include medicines to thin the blood and slow its ability to clot. If your symptoms are life threatening, your doctor may give you medicine to dissolve the clot more quickly. Rarely, your doctor may use surgery or another procedure to remove the clot.
Anticoagulants, or blood thinners, decrease your blood's ability to clot. They're used to stop blood clots from getting bigger and to prevent clots from forming. Blood thinners don't break up blood clots that have already formed. (The body dissolves most clots with time.) Blood thinners can be taken as either a pill, an injection, or through a needle or tube inserted into a vein (called intravenous, or IV, injection). Warfarin is given in a pill form. (Coumadin® is a common brand name for warfarin.) Heparin is given as an injection or through an IV tube. Your doctor may treat you with both heparin and warfarin at the same time. Heparin acts quickly. Warfarin takes 2 to 3 days before it starts to work. Once warfarin starts to work, usually the heparin is stopped.
Pregnant women usually are treated with heparin only, because warfarin is dangerous for the pregnancy. If you have deep vein thrombosis, treatment with blood thinners usually lasts for 3 to 6 months. If you've had blood clots before, you may need a longer period of treatment. If you're being treated for another illness, such as cancer, you may need to take blood thinners as long as risk factors for PE are present. The most common side effect of blood thinners is bleeding. This happens if the medicine thins your blood too much. This side effect can be life threatening. Sometimes, the bleeding can be internal. This is why people treated with blood thinners usually have regular blood tests. These tests are called PT and PTT tests, and they measure the blood's ability to clot. These tests also help your doctor make sure you're taking the right amount of medicine. Call your doctor right away if you're bruising or bleeding easily. Thrombin inhibitors are a newer type of blood-thinning medicine. They're used to treat some types of blood clots in people who can't take heparin.
When PE is life threatening, doctors may use treatments that remove or break up clots. These treatments are given in an emergency room or hospital. Thrombolytics are medicines that can quickly dissolve a blood clot. They're used to treat large clots that cause severe symptoms. Because thrombolytics can cause sudden bleeding, they're used only in life-threatening situations. In some cases, the doctor may use a catheter to reach the blood clot. A catheter is a flexible tube placed in a vein to allow easy access to the bloodstream for medical treatment. The catheter is inserted into the groin (upper thigh) or arm and threaded through a vein to the clot in the lung. The catheter may be used to extract the clot or deliver medicine to dissolve it.
Rarely, surgery may be needed to remove the blood clot.
Other Types of Treatment
When you can't take medicines to thin your blood or your medicines don't work, your doctor may use a device called a vena cava filter to keep clots from traveling to your lungs. The filter is inserted inside a large vein called the inferior vena cava (the vein that carries blood from the body back to the heart). The filter catches clots before they travel to the lungs. This prevents PE, but it doesn't stop other blood clots from forming. Graduated compression stockings can reduce the chronic (ongoing) swelling that a blood clot in the leg may cause. The leg swelling is due to damage to the valves in the leg veins. Graduated compression stockings are worn on the legs from the arch of the foot to just above or below the knee. These stockings are tight at the ankle and become looser as they go up the leg. This causes a gentle compression (or pressure) up the leg. The pressure keeps blood from pooling and clotting.
Pulmonary Embolism Prevention
Preventing pulmonary embolism (PE) begins with preventing deep vein thrombosis (DVT). Knowing whether you're at risk for DVT and taking steps to lower your risk are important.
If you've never had a deep vein clot but are at risk for one, you can take steps to lower your risk.
- Exercise your lower leg muscles during long car trips and airplane rides.
- Get out of bed and move around as soon as you're able after having surgery or being ill. The sooner you move around, the lower your chance of developing a clot.
- Take medicines to prevent clots after some types of surgery (as your doctor prescribes).
- Follow up with your doctor.
If you've already had DVT or PE, you can take additional steps to prevent new blood clots from forming. Visit your doctor for regular checkups. Also, use compression stockings to prevent chronic swelling in your legs after DVT (as your doctor advises).
Contact your doctor right away if you have any signs or symptoms of DVT or PE.
Living With Pulmonary Embolism
Pulmonary embolism (PE) usually is treated in a hospital. After leaving the hospital, you may need to take medicine at home for 6 months or longer. It's important to:
- Take medicines as prescribed.
- Have blood tests done as your doctor advises.
- Talk to your doctor before taking blood-thinning medicines with any other medicine, including over-the-counter products. Over-the-counter aspirin, for example, can thin your blood. Taking two medicines that thin your blood (even if one is over-the-counter) may increase your risk for bleeding.
- Ask your doctor about your diet. Foods that contain vitamin K can affect how well warfarin (Coumadin®) works. Vitamin K is found in green leafy vegetables and some oils, such as canola and soybean oils. It's best to eat a well-balanced, healthy diet.
- Discuss with your doctor what amount of alcohol is safe for you to drink if you're taking medicine.
Medicines used to treat PE can thin your blood too much. This can cause bleeding in the digestive system or the brain. If you have signs or symptoms of bleeding in the digestive system or the brain, get treatment at once.
Signs and symptoms of bleeding in the digestive system include:
- Bright red vomit or vomit that looks like coffee grounds
- Bright red blood in your stool or black, tarry stools
- Pain in your abdomen
Signs and symptoms of bleeding in the brain include:
- Severe pain in your head
- Sudden changes in your vision
- Sudden loss of movement in your legs or arms
- Memory loss or confusion
Excessive bleeding from a fall or injury also may mean that your PE medicines have thinned your blood too much. Excessive bleeding is bleeding that won't stop after you apply pressure to a wound for 10 minutes. If you have excessive bleeding from a fall or injury, get treatment at once.
Once you've had PE (with or without deep vein thrombosis (DVT)), you have a greater chance of having it again. During treatment and after, continue to take steps to prevent DVT. Check your legs for any signs or symptoms of DVT, such as swollen areas, pain or tenderness, increased warmth in swollen or painful areas, or red or discolored skin.
If you think that you have DVT or are having symptoms of PE, contact your doctor right away.
Reference: National Heart Lung and Blood Institute
Lst updated May 2, 2017