Pulmonary Embolism

What is pulmonary embolism?

Pulmonary embolism occurs when an artery to the lungs is blocked. Generally, the blockage is caused by one or more blood clots that travel to your lungs from another part of your body. In most cases, pulmonary embolisms are tiny and are not life-threatening. but even small pulmonary embolisms are a main cause of hospital mortality and an increasing threat to passengers on prolonged airplane flights. In most circumstances that increase the risk of forming a blood clot, preventative measures can be quite effective in avoiding a pulmonary embolism.

What are the varieties?

Most pulmonary emboli are the result of blood clots. Partially due to the effects of gravity, blood clots generally form in the legs, but they can also develop in the arm veins, the right side of the heart or even at the tip of a catheter inserted into a vein to deliver intravenous fluids or medications. Occasionally, other substances circulating in the bloodstream, such as a globule of fat from the inside of a broken bone, tissue from a tumor or a clump of bacteria, may get stuck in the arteries of the lungs.

What are the causes of pulmonary embolism?

Clots that develop in the veins can dislodge, move through the bloodstream to the right side of the heart, where they are pumped to the pulmonary arteries and form a blockage. A emboli can take place in any small artery in any part of the body, but the lungs are at greater risk because the pulmonary arteries all narrow down to tiny blood vessels called capillaries to allow the exchange of oxygen in the lungs, and all of the blood in the body passes through the lungs every time it circulates. Typically, multiple small clots will develop over a period of minutes or hours and become lodged in arteries going to all parts of your lungs. It is unusual for just one clot to develop, but larger clots forming in the deep veins of the legs can cause considerable damage. Most clots in the legs originate in the veins below the knee, and although it is unusual for these clots to detach and travel up into the thigh, when they do the situation becomes much more serious. Factors involved in clot formation include surgery, long periods of inactivity, increased levels of clotting factors in the blood, certain medical conditions and injury to the veins.

Who is likely to get it?

The following are risk factors for development of a pulmonary embolism:

• Inactivity
• Prolonged bed rest
• Certain surgical procedures
• Being overweight
• Pacemakers or venous catheters
• Pregnancy and childbirth
• Taking birth control pills
• Family history
• Smoking
• Some medical conditions. (especially pancreatic, ovarian and lung cancers and chemotherapy, menopausal women with a history of breast cancer who are taking tamoxifen or raloxifene, those with hypertension and cardiovascular disease, or inflammatory bowel disease [for example, ulcerative colitis or Crohn’s disease]).

What are the symptoms of pulmonary embolism?

Common signs and symptoms include:

• Acute onset of shortness of breath, either when you are active or at rest
• A cough with bloody or blood-streaked sputum
• Excessive perspiration
• Rapid heartbeat (tachycardia)
• Lightheadedness or fainting (syncope)
• Wheezing
• Clammy or bluish-colored skin
• Leg swelling
• Weak pulse
• Sudden, unfocused sense of physical threat
• Chest pain that seems like a heart attack. The pain can be located anywhere in your chest and may radiate to your shoulder, arm, neck or jaw. It can be sharp and stabbing or aching and dull and may get worse when you breathe deeply, cough, eat, bend or stoop. The pain will be exacerbated with exertion but does not reside when you rest.

How is pulmonary embolism diagnosed?

Pulmonary embolism is often difficult to diagnose, especially in people with concurrent heart or lung disease. Physicians often perform one or more tests to help find the root cause. These tests may include the following:

• Chest X-ray
• Lung scan
• Pulmonary angiogram
• Spiral (helical) computerized tomography (CT) scan.

Tests to detect blood clots:

• D-dimer blood test
• Ultrasound
• Venography
• Magnetic resonance imaging (MRI)
• Blood tests.

What is the conventional treatment of pulmonary embolism?

Immediate medical attention is essential with a pulmonary embolism to avoid or reduce the risk of more serious complications. Initially you will be given the fast-acting anticoagulant heparin, which helps prevent current clots from growing and halts the formation of new ones. Your physician may also prescribe the anticoagulant warfarin. Because it takes longer to work than heparin does, the two are used in combination. After the original clot is gone, you may well continue to take an anticoagulant medication. If you have a chronic condition that puts you at an elevated risk of forming blood clots, you may be required to stay on these medications indefinitely. You will usually take them for at least six months. Heparin and warfarin decrease the chance of developing blood clots, but they also prevent normal blood coagulation, meaning that they increase your risk of bleeding complications. If you are prescribed warfarin, your doctor will request periodic blood tests to determine how well the drug is working. During anticoagulant therapy, do not use aspirin and other nonsteroidal anti-inflammatory drugs like ibuprofen, which also affect your blood’s ability to clot. Because over 100 other medications, including over-the-counter medications and some herbs, can interact with anticoagulants, it is crucial to make sure your physician knows all of the medications (both prescription and over-the-counter), herbs, supplements and vitamins you take. If you experience a major pulmonary embolism, if you have exacerbated cardiopulmonary disease, or if other treatments are not working, clot-dissolving (thrombolytic) therapy, or the placement of a vein filter might be considered as treatment options.

What are the therapies Dr. Weil recommends for pulmonary embolism?

High blood pressure is known to be a risk factor for a pulmonary embolism. With regard to treating high blood pressure, Dr. Weil suggests:

• Limit your caffeine intake. The caffeine in coffee, tea and sodas can contribute to high blood pressure.
• Limit alcohol intake. Blood pressure increases as your body metabolizes alcohol.
• Avoid processed foods. These are the biggest sources of sodium in today’s diet.
• Maintain optimal weight. Even small amounts of weight loss can improve blood pressure.
• Relax. Meditation, yoga, breathing exercises and biofeedback are all relaxation techniques that can help lower blood pressure.
• Don’t smoke. Smoking contributes to all cardiovascular diseases – and many other life-threatening conditions as well.
• Exercise. As little as 30 minutes of moderate exercise a day, like walking, can lower blood pressure.
• Check your meds. Discuss your current medications and their risks of increasing blood pressure with your doctor.

Follow the DASH diet.

Developed by researchers at the National Institutes of Health’s National Heart, Lung, and Blood Institute, the Dietary Approaches to Stop Hypertension (DASH) diet is based on a large-scale research study that identified the foods that affect blood pressure (see the National Institutes of Health’s Web site for more information). The most important parts of the DASH are generous amounts of fruits and vegetables and low-fat or fat-free dairy products that provide adequate calcium. The diet is also relatively low in fat and sodium. DASH researchers have shown that diets rich in potassium, calcium and magnesium, and low in sodium (2,400 mg or less), play an important role in maintaining healthy blood pressure levels. People with high blood pressure should incorporate the components of the DASH diet into their daily routine.

• Eat 8 to 10 servings of fruit and vegetables per day
• Limit animal protein to 6 oz per day, emphasizing lean sources.
• Say no to salt. Those with salt sensitivity or a family history or hypertension may benefit from reducing salt to about one teaspoon a day (2,400 mg).
• Use garlic, which has a modest effect on lowering blood pressure and may help relax blood vessels.
• Consume 4 to 5 servings of nuts, seeds and dry beans per week (2 Tbsp nuts or seeds, or 1/2 cup cooked dried beans).
• Eat plenty of fish. Include at least three servings of fish a week, emphasizing cold-water fish like wild Alaskan salmon and sardines, which are rich in omega-3 fatty acids. Take fish-oil supplements if you cannot get enough omega-3-rich foods.
• Take calcium and magnesium. Inadequate intake of both of these minerals has been associated with high blood pressure. Women should get between 1,000 and 1,200 mg of calcium a day from all sources, while men may want to get no more than 500-600 mg daily from all sources, and probably do not need to take supplements.
• Take vitamin C. A supplement of this antioxidant vitamin has been shown to help lower blood pressure in people with mild to moderate hypertension.

Can pulmonary embolism be prevented?

Blood clots can form when circulation is sluggish or when venous blood becomes pooled in a vein. Remaining seated during a long flight or drive increases your risk of developing blood clots in the veins of your legs. To help prevent a blood clot from developing, stay active:

• Take a walk.
• Exercise while you sit.
• Wear support stockings.
• Drink plenty of fluids before and during the trip. (Note that water is the optimal beverage of choice and avoiding alcohol is definitely recommended.)
• Talk to your doctor. If you have a heightened risk of blood clot development and plan to fly six hours or more, your doctor may suggest low-molecular-weight heparin two to four hours before your departure.