Lung Embolus - Pulmonary Embolus

An embolus is any material that travels through the bloodstream and then gets stuck in a blood vessel. When an embolus occurs in the veins that lead to the lungs, it is called a pulmonary embolus.

What is going on in the body?

A pulmonary embolus can occur for many different reasons. The embolus travels through the bloodstream until it reaches a blood vessel to the lungs that is too narrow. The embolus then gets stuck in the blood vessel and keeps the blood from flowing beyond it. A pulmonary embolus may be tiny and never noticed, or it may be large enough to cause death.

What are the causes and risks of the condition?

A pulmonary embolus may be caused by:

Since deep venous thrombosis (DVT) is the most common cause of pulmonary embolus, factors that increase the risk of DVT are also risk factors for pulmonary embolus. Risk factors that increase an individual's risk of developing DVT include: cancer

Recently, there have been conflicting research reports about the role of long airplane flights in deep venous thrombosis. One study of people with DVT found no significant travel patterns in these individuals. The results were true whether they traveled by car, plane, bus, or train.

A second study, however, showed a relationship between airline travel and an increase in the blood's tendency to form clots. The researchers attributed the increased risk of clot formation to the low pressure and reduced oxygen on the planes. The clotting was also increased by the dehydration and inactivity on long flights.

A third study looked at individuals hospitalized with DVT. These people were four times more likely to have gone on a long trip recently than those treated at the hospital for other conditions. Because of findings like this, deep venous thrombosis is often referred to as "economy class syndrome."

What are the signs and symptoms of the condition?

A pulmonary embolus may cause:

How is the condition diagnosed?

The diagnosis of pulmonary embolus starts with a medical history and physical examination. Diagnostic tests may include:

What can be done to prevent the condition?

Since deep venous thromboses are the major cause of a pulmonary embolus. Measures to prevent DVT will go a long way toward lowering a person's risk of pulmonary embolus. Avoiding long periods of inactivity can reduce the risk of DVT. This is especially important for people who have a history of DVT. For example, it's good to start to walk soon after surgery or an injury.

Although the research is still inconclusive about the effects of airplane trips, people can lower their risk of DVT by:

Blood-thinning medications can help prevent DVT. These include heparin, enoxaparin, and warfarin. Compression stockings can also be used to improve the flow of blood back up to the heart.

Scuba divers should follow proper procedure and not return to the surface too quickly. Intravenous drug abuse should be avoided.

What are the long-term effects of the condition?

A pulmonary embolus can cause permanent lung damage and death. Congestive heart failure, a condition in which a weakened heart cannot pump enough blood through the body, can also occur

What are the risks to others?

A pulmonary embolus is not contagious and poses no risk to others.

What are the treatments for the condition?

Oxygen and pain medications are given as needed. If the pulmonary embolus is caused by a DVT, bed rest and elevating the leg can help reduce the swelling and pain.

People with a deep venous thrombosis are usually given an injection of a blood-thinning medication. The injection may be given through an IV or under the skin. These medications, such as heparin and enoxaparin, help prevent further growth of the blood clot. After a few days of blood-thinning medications by injection, the person can be switched to pills. Warfarin is the most common blood-thinning pill.

In some people, blood-thinning medications cannot be used for various reasons. For example, a person may have a high risk of bleeding. In these cases, a surgical procedure can be done. This involves inserting a filter in one of the major veins of the body that leads to the heart. This filter catches any clots that break off. It keeps the clots away from the lungs.

What are the side effects of the treatments?

Heparin can cause bleeding and lower blood platelet counts. Warfarin can also cause bleeding, which in rare cases is fatal. Warfarin interferes with many other medications. Surgery can cause bleeding, infection, or allergic reaction to anesthesia.

What happens after treatment for the condition?

A person's condition after treatment will vary, depending on the cause of the pulmonary embolus. For example, a woman who recovers from a fluid embolus during pregnancy is free to return to normal activities. No further treatment may be needed.

If the cause of an embolus is a blood clot, a person usually needs to take blood thinners, such as warfarin. Treatment usually lasts for several months. A person who has had more than one pulmonary embolus may need to take blood thinners for life.

If blood thinners cannot be tolerated for some reason, a person may need to undergo a special procedure. This procedure inserts a filtering device in a major vein leading back to the heart. The filter stops an embolus from getting into the lungs.

How is the condition monitored?

Individuals on blood-thinning medications will have periodic blood tests to monitor the thickness of their blood. Any new or worsening symptoms should be reported to the healthcare provider.

Author:Adam Brochert, MD
Date Written:
Editor:Crist, Gayle P., MS, BA
Edit Date:03/30/01
Reviewer:Eileen McLaughlin, RN, BSN
Date Reviewed:08/06/01

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