Pulmonary embolism

Pulmonary embolism

Definition:

Pulmonary embolism is blockage in one or more arteries in your lungs. In most cases, pulmonary embolism is caused by blood clots that travel to your lungs from another part of your body — most commonly, your legs. Pulmonary embolism is a complication of deep vein thrombosis (DVT), which is clotting in the veins farthest from the surface of the body.

Pulmonary embolism can occur in otherwise healthy people. Common signs and symptoms include sudden and unexplained shortness of breath, chest pain and a cough that may bring up blood-tinged sputum.

Pulmonary embolism can be life-threatening, but immediate treatment with anti-clotting medications can greatly reduce the risk of death. Taking measures to prevent blood clots in your legs also can help protect you against pulmonary embolism.

Symptoms:

Pulmonary embolism symptoms can vary greatly, depending on how much of your lung is involved, the size of the clot and your overall health — especially the presence or absence of underlying lung disease or heart disease.
Common signs and symptoms include:

• Shortness of breath. This symptom typically appears suddenly, and occurs whether you're active or at rest.
  
• Chest pain. You may feel like you're having a heart attack. The pain may become worse when you breathe deeply, cough, eat, bend or stoop. The pain will get worse with exertion but won't go away when you rest.
  
• Cough. The cough may produce bloody or blood-streaked sputum.

Other signs and symptoms that can occur with pulmonary embolism include:

• Wheezing
• Leg swelling, usually in only one leg
• Clammy or bluish-colored skin
• Excessive sweating
• Rapid or irregular heartbeat
• Weak pulse
• Lightheadedness or fainting

When to see a doctor
Pulmonary embolism can be life-threatening. Seek immediate medical attention if you experience unexplained shortness of breath, chest pain or a cough that produces bloody sputum.

Causes:

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 originate in the deep veins of your legs, but they can also come from other parts of your body. This condition is known as deep vein thrombosis (DVT). Not all DVT blood clots result in pulmonary embolism.
Occasionally, other substances can form blockages within the blood vessels inside your lungs. Examples include:

• Fat from within the marrow of a broken bone
• Part of a tumor
• Air bubbles

It's rare to experience a solitary pulmonary embolism. In most cases, multiple clots are involved. The lung tissue served by each blocked artery is robbed of fuel and may die. This makes it more difficult for your lungs to provide oxygen to the rest of your body.
Because pulmonary embolism almost always occurs in conjunction with deep vein thrombosis, most doctors refer to the two conditions together as venous thromboembolism (VTE).

Treatments and drugs:


Prompt treatment of pulmonary embolism is essential to prevent serious complications or death.
Medications
Medications to treat pulmonary embolism include:

• Anticoagulants. The drugs heparin and warfarin (Coumadin) prevent new clots from forming. Heparin works quickly and is usually delivered with a needle. Warfarin (Coumadin) comes in pill form and doesn't start working until a few days after your first dose. Risks include bleeding and easy bruising.
  
• Clot dissolvers (thrombolytics). While clots usually dissolve on their own, certain medications can dissolve clots quickly. Because these clot-busting drugs can cause sudden and severe bleeding, they usually are reserved for life-threatening situations.

Surgical and other procedures
In some cases, your doctor might recommend a procedure to treat pulmonary embolism, such as:

• Clot removal. If you have a very large clot in your lung and you're in shock, your doctor may thread a thin flexible tube (catheter) through your blood vessels and suction out the clot. It can be difficult to remove a clot this way, and this procedure isn't always successful.
  
• Vein filter. A catheter can also be used to place a filter in the main vein — called the inferior vena cava — that leads from your legs to the right side of your heart. This filter catches and stops blood clots moving through the blood stream toward your lungs. Filter insertion is typically reserved for people who can't take anticoagulant drugs or when anticoagulant drugs don't work well enough.
  
• Surgery. If you're in shock and thrombolytic medication isn't working quickly enough, your doctor might attempt emergency surgery. This happens infrequently, and the goal is to remove as many blood clots as possible, especially if there's a large clot in your main (central) pulmonary artery.