Pulmonary embolism is often caused by blood clots that travel to the lungs from the legs. Prevention is aimed at stopping clots from forming in the legs.
Pulmonary embolism is a blockage in one of the pulmonary arteries in your lungs. In most cases, pulmonary embolism is caused by blood clots that travel to the lungs from deep veins in the legs or, rarely, from veins in other parts of the body (deep vein thrombosis).
Because the clots block blood flow to the lungs, pulmonary embolism can be life-threatening. However, prompt treatment greatly reduces the risk of death. Taking measures to prevent blood clots in your legs will help protect you against pulmonary embolism.
Pulmonary embolism symptoms can vary greatly, depending on how much of your lung is involved, the size of the clots, and whether you have underlying lung or heart disease.
Common signs and symptoms include:
Other signs and symptoms that can occur with pulmonary embolism include:
Pulmonary embolism can be life-threatening. Seek urgent medical attention if you experience unexplained shortness of breath, chest pain or a cough that produces bloody sputum.
Pulmonary embolism occurs when a clump of material, most often a blood clot, gets wedged into an artery in your lungs. These blood clots most commonly come from the deep veins of your legs, a condition known as deep vein thrombosis (DVT).
In many cases, multiple clots are involved in pulmonary embolism. The portions of lung served by each blocked artery are robbed of blood and may die. This is known as pulmonary infarction. This makes it more difficult for your lungs to provide oxygen to the rest of your body.
Occasionally, blockages in the blood vessels are caused by substances other than blood clots, such as:
Although anyone can develop blood clots and subsequent pulmonary embolism, certain factors can increase your risk.
You're at higher risk if you or any of your family members have had venous blood clots or pulmonary embolism in the past.
In addition, some medical conditions and treatments put you at risk, such as:
Blood clots are more likely to form during periods of inactivity, such as:
Pulmonary embolism can be life-threatening. About one-third of people with undiagnosed and untreated pulmonary embolism don't survive. When the condition is diagnosed and treated promptly, however, that number drops dramatically.
Pulmonary embolism can also lead to pulmonary hypertension, a condition in which the blood pressure in your lungs and in the right side of the heart is too high. When you have obstructions in the arteries inside your lungs, your heart must work harder to push blood through those vessels, which increases blood pressure and eventually weakens your heart.
In rare cases, small emboli occur frequently and develop over time, resulting in chronic pulmonary hypertension, also known as chronic thromboembolic pulmonary hypertension.
Preventing clots in the deep veins in your legs (deep vein thrombosis) will help prevent pulmonary embolism. For this reason, most hospitals are aggressive about taking measures to prevent blood clots, including:
The risk of blood clots developing while traveling is low, but increases as long-haul travel increases. If you have risk factors for blood clots and you're concerned about travel, talk with your doctor.
Your doctor might suggest the following to help prevent blood clots during travel:
Pulmonary embolism can be difficult to diagnose, especially in people who have underlying heart or lung disease. For that reason, your doctor will likely discuss your medical history, do a physical exam, and order one or more of the following tests.
Your doctor may order a blood test for the clot-dissolving substance D dimer. High levels may suggest an increased likelihood of blood clots, although many other factors can also cause high D dimer levels.
Blood tests also can 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.
In addition, blood tests may be done to determine whether you have an inherited clotting disorder.
This noninvasive test shows images of your heart and lungs on film. Although X-rays can't diagnose pulmonary embolism and may even appear normal when pulmonary embolism exists, they can rule out conditions that mimic the disease.
A noninvasive test known as duplex ultrasonography (sometimes called duplex scan or compression ultrasonography) uses sound waves to scan the veins in your thigh, knee and calf, and sometimes in your arms, to check for deep vein blood clots.
A wand-shaped device called a transducer is moved over the skin, directing the sound waves to the veins being tested. These waves are then reflected back to the transducer to create a moving image on a computer. The absence of clots reduces the likelihood of deep vein thrombosis. If clots are present, treatment likely will be started immediately.
CT scanning generates X-rays to produce cross-sectional images of your body. CT pulmonary angiography ― also called CT pulmonary embolism study ― creates 3D images that can detect abnormalities such as pulmonary embolism within the arteries in your lungs. In some cases, contrast material is given intravenously during the CT scan to outline the pulmonary arteries.
When there is a need to avoid radiation exposure or contrast from a CT scan due to a medical condition, a V/Q scan may be performed. In this test, a tracer is injected into a vein in your arm. The tracer maps blood flow (perfusion) and compares it with the airflow to your lungs (ventilation) and can be used to determine whether blood clots are causing symptoms of pulmonary hypertension.
This test provides a clear picture of the blood flow in the arteries of your lungs. It's the most accurate way to diagnose pulmonary embolism, but because it requires a high degree of skill to administer and has potentially serious risks, it's usually performed when other tests fail to provide a definitive diagnosis.
In a pulmonary angiogram, a flexible tube (catheter) is inserted into a large vein — usually in your groin — and threaded through your heart and into the pulmonary arteries. A special dye is then injected into the catheter, and X-rays are taken as the dye travels along the arteries in your lungs.
In some people, this procedure may cause a temporary change in heart rhythm. In addition, the dye may cause increased risk of kidney damage in people with reduced kidney function.
MRI is a medical imaging technique that uses a magnetic field and computer-generated radio waves to create detailed images of the organs and tissues in your body. MRI is usually reserved for pregnant women (to avoid radiation to the fetus) and people whose kidneys may be harmed by dyes used in other tests.
Treatment of pulmonary embolism is aimed at keeping the blood clot from getting bigger and preventing new clots from forming. Prompt treatment is essential to prevent serious complications or death.
Medications include different types of blood thinners and clot dissolvers.
Blood thinners (anticoagulants). These drugs prevent existing clots from enlarging and new clots from forming while your body works to break up the clots. Heparin is a frequently used anticoagulant that can be given through the vein or injected under the skin. It acts quickly and is often overlapped for several days with an oral anticoagulant, such as warfarin, until it becomes effective, which can take days.
Newer oral anticoagulants work more quickly and have fewer interactions with other medications. Some have the advantage of being given by mouth, without the need for overlap with heparin. However, all anticoagulants have side effects, and bleeding is the most common.
Because you may be at risk of another deep vein thrombosis or pulmonary embolism, it's important to continue treatment, such as remaining on blood thinners, and be monitored as often as suggested by your doctor. Also, keep regular doctor visits to prevent or treat complications.
Pulmonary embolism is often initially evaluated in hospitals, emergency rooms or urgent care centers. If you think you might have a pulmonary embolism, seek immediate medical attention.
You may want to prepare a list that includes:
During the physical exam, your doctor will likely inspect your legs for evidence of a deep vein clot — an area that's swollen, tender, red and warm. He or she will also listen to your heart and lungs and check your blood pressure, and will likely order one or more tests.
October 27th, 2021
