Pulmonary embolism (PE) is an extremely common and highly lethal condition that is a leading cause of death in all age groups. A good clinician actively seeks the diagnosis as soon as any suspicion of PE whatsoever is warranted, because prompt diagnosis and treatment can dramatically reduce the mortality rate and morbidity of the disease. Unfortunately, the diagnosis is missed more often than it is made, because PE often causes only vague and nonspecific symptoms.
The lungs are a pair of organs in the chest that are primarily responsible for the exchange of oxygen and carbon dioxide between the air we breathe and blood. The lung is composed of clusters of small air sacs (alveoli) divided by thin, elastic walls (membranes). Capillaries, the tiniest of blood vessels, run within these membranes between the alveoli and allow blood and air to come near each other.

Symptoms

Symptoms of PE are sudden-onset dyspnea (shortness of breath), tachypnea (rapid breathing), chest pain of “pleuritic” nature (worsened by breathing), cough, hemoptysis (coughing up blood), and may aid in the diagnosis. More severe cases can include signs such as pleural rub, cyanosis (blue discoloration, usually of the lips and fingers), collapse, and circulatory instability. About 15% of all cases of sudden death are attributable to PE.

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.

Chest pain that often mimics a heart attack. The pain can occur anywhere in your chest and may radiate to your shoulder, arm, neck or jaw. It may be sharp and stabbing or aching and dull and may become worse when you breathe deeply (pleurisy), cough, eat, bend or stoop. The pain will get worse with exertion but won’t go away when you rest.

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.

Causes

Physiological risk factors include venous stasis (poor blood flow in the veins), venous injury (injury to the veins), and having a condition or illness that predisposes to clotting (cancer, certain blood protein deficiencies, infection). Older persons seem to have a higher risk for pulmonary embolism, as do obese persons and women taking oral contraceptives. Some people have inherited abnormalities in blood clotting that make them more likely to have pulmonary embolism.

Microscopic thrombi, or clots, are continually being made in the bloodstream. Normally, these are broken down quickly, but under certain conditions they grow to form a larger clot that blocks a vein. This is called deep vein thrombosis (DVT).

Clots that form in the veins throughout your body can dislodge, travel through the bloodstream to the right side of the heart, and then enter the pulmonary arteries, where they may cause a blockage. A blockage can occur in any small artery, but the lungs are especially vulnerable because all of the blood in the body passes through the lungs every time it circulates. Most often, a number of clots will shower your lungs during an episode of pulmonary embolism; it’s unusual for just one clot to take place.

Pulmonary embolism is a condition that occurs when an artery in your lung becomes blocked. In most cases, the blockage is caused by one or more blood clots that travel to your lungs from another part of your body. Most clots originate in your legs, but they can also form in arm veins, the right side of your heart or even at the tip of a catheter placed in a vein. There are other rare causes of clots as well.

Pulmonary emboli are caused by clots from the venous circulation, from the right side of the heart, from tumours that have invaded the circulatory system, or from other sources such as amniotic fluid, air, fat, bone marrow, and foreign substances. Most pulmonary embolus are caused from clots originating in the lower extremities (deep vein thrombosis), and many resolve on their own. In some cases, pulmonary embolism can cause sudden death.

The symptoms you feel can depend on the location and size of your blood clot. Shortness of breath is the most common symptom. Other symptoms include rapid breathing; anxiety and restlessness; chest pain, which might extend into your shoulder, arm, neck, and jaw; coughing or spitting up blood; feeling lightheaded or fainting; and having a rapid heartbeat.

Half the people who have pulmonary embolism have no symptoms. If you do have symptoms, they can include shortness of breath, chest pain or coughing up blood. Symptoms of a blood clot include warmth, swelling, pain, tenderness and redness of the leg. The goal of treatment is to break up clots and help keep other clots from forming.

A pulmonary embolism (PE) is a blood clot in the lung. It usually comes from smaller vessels in the leg, pelvis, arms, or heart. When a clot forms in the legs or arms, it is referred to as a deep venous thrombosis (DVT). The clot travels through the vessels of the lung continuing to reach smaller vessels until it becomes wedged in a vessel that is too small to allow it to continue farther. The clot gets wedged and prevents any further blood from traveling to that section of the lung.

An embolism occurs when foreign material, such as a blood clot or air bubble, travels through the bloodstream and becomes lodged in a blood vessel, blocking the flow of blood. Embolisms can occur in veins, which carry oxygen-poor blood back to the heart and lungs, as well as arteries, which carry oxygen-rich blood from the heart to the tissues of the body.

Pulmonary emboli are most often caused by blood clots in the veins, especially veins in the legs or in the pelvis (hips). More rarely, air bubbles, fat droplets, amniotic fluid, or clumps of parasites or tumor cells may obstruct the pulmonary vessels.The most common cause of a pulmonary embolism is a blood clot in the veins of the legs, called a deep vein thrombosis (DVT). Many clear up on their own, though some may cause severe illness or even death.

When blood supply is lost, tissues are starved of oxygen, causing them to die. If this happens in your brain, it can cause permanent brain damage. After the arteries have carried oxygen to all the body’s tissues, the de-oxygenated blood is returned to the heart in the veins. If the embolus is in a vein, the tube system widens in the same direction as the blood flows, so its unlikely to get stuck.

Copyright (c) 2009 Dr. Jennifer Feeny

Deep vein thrombosis (DVT) is a condition in which a blood clot (a blockage) forms in a deep vein. Although these clots usually occur in the veins of the leg, they can also develop in other parts of the body. A DVT is considered a medical emergency and if you suspect that you or a loved one might have a DVT, please seek medical attention immediately. News correspondent David Bloom died in 2003 from a DVT at age 39. It is wise to familiarize yourself with the symptoms and risk factors because knowing this information may save your life.

Risk factors

A person who is inactive for an extended period of time is at increased risk of DVT. This can happen during a long airline flight, while wearing a cast, following surgery and even when in the hospital for another condition. Other risk factors include:

* Varicose veins

* Blood clotting disorders

* Family history of DVT or clotting disorders

* Heart disease

* Obesity

* Chronic leg swelling

* Dehydration

* Birth Control Pills containing estrogen

* Hormone replacement therapy

* Pregnancy/recent childbirth

* Smoking

* Age (over 40 years old)

* Trauma

* Recent surgery

The more risk factors a person has, the greater the risk of developing a DVT. But, anyone can develop a DVT, even people without any of these risk factors.

Symptoms

The most common warning signs are calf tenderness, swelling, warmth and/or redness of the leg. However, some people with a DVT have no symptoms or just a very mild discomfort in the leg.

A serious complication of DVT is a pulmonary embolism, which may cause death. This happens when a clot breaks loose from the leg and travels to the lung. Symptoms of a pulmonary embolism include:

* Shortness of breath

* Chest pain

* Tightness in chest

* Coughing up blood

Another complication of a DVT is damage to the vein from the blood clot which can result in chronic swelling, pain and discoloration of that leg.

Diagnosis

Diagnosis can be challenging for a physician, especially when symptoms are vague. Leg swelling can be cause by congestive heart failure or venous insufficiency. Calf tenderness could be caused by tendonitis. If a DVT is suspected, a doctor will order tests that can detect a blood clot in the leg. The most accurate for diagnosis is the venogram. A venogram involves injecting dye into the vein and taking pictures to determine if there is a blockage. A less invasive option is a Duplex Ultrasound. Due to its high sensitivity and specificity, Duplex Ultrasound has replaced venography as the most widely used test in evaluation of DVT. Duplex Ultrasonography is safe in pregnancy and for those allergic to contract dyes used in venograms.

Treatment

There are a few options that your doctor may recommend in the treatment of DVT. Anticoagulants, like heparin or coumadin, may be prescribed to thin the blood to prevent accrual or formation of new clots. If you are unable to take anticoagulants, a filter may be placed in a large vein called the inferior vena cava to capture the clots. Compression stockings may be used to control swelling in the legs.

Prevention

If you have risk factors for a DVT, consider these tips for reducing the likelihood of developing a blood clot:

* Exercise you legs every 2 to 3 hours when on a long trip. Walk the aisles of a plane or train, and take regular breaks during a car trip.

* Drink plenty of fluids; avoid alcohol and caffeine.

* Wear Compression stockings.

* Take blood thinning medications, if prescribed by your doctor.

* If you are hospitalized, or having surgery, discuss preventative medication with your physician.

Each year, at least 100,000 deaths are attributed to deep venous thrombosis and pulmonary embolisms. About 1 in every 1000 adults develop a DVT in a given year. Deep vein throbosis is a common, serious medical condition that all adults should be aware of. Early symptom recognition and diagnosis improves outcomes and saves lives.