What is Pulmonary Embolism: Symptoms, Risk Factors and Treatments

What is Pulmonary Embolism

Pulmonary embolism happens when arteries in the lung become blocked, usually by blood clots that have traveled to the lungs from elsewhere in the body. Blood clots in the lower extremities are known as "deep vein thrombosis" or DVT and in most cases dissolve on their own. When they don't and end up in the lungs, they can cause sudden death.

Blood clots are not the only thing that can cause pulmonary embolism. Amniotic fluid, fat, air, bone marrow, foreign substances, and tumor tissue can also block arteries.

Pulmonary embolism can happen to anyone, healthy or not, and usually involve more than one artery.

Symptoms

As with most health conditions, signs and symptoms vary in onset and severity from patient to patient. If you experience any of the below symptoms especially in combination, see your doctor immediately.

a sudden cough that produces blood in the mucus or visible blood or phelgm that is lightly streaked with blood

sudden onset of shortness of breath at rest or with exertion

splinting of ribs with breathing (sharp pain)

lightheadedness, dizziness, or fainting

weak pulse

excessive sweating, rapid breathing, and rapid heart rate

leg swelling

clammy or bluish-tinged skin

chest pain under the breastbone or on side which may worsen at night or by breathing deeply, coughing, eating, bending or stooping, and may radiate (spread) to the shoulder, arm, neck, jaw, or other area

Having any one or a combination of these symptoms does not necessarily mean that you have pulmonary embolus. These symptoms can be caused by other illnesses or pre-existing conditions. Only a doctor will be able to tell you. Regardless, any of these symptoms require immediate evaluation and treatment. In the case of pulmonary embolism, not addressing the issue can lead to death.

Blood clots have been known to develop in people following:

prolonged bed rest or inactivity (ex: travel)

smoking

being overweight

use of oral contraceptives or hormone replacement therapy (HRT)

surgery

child birth

cancer

stroke

heart attack

heart surgery

hip or femur fractures

It can also happen in older people as a result of a valve malfunction (where the valves in the veins that normally keep blood moving in the right direction stop working properly), dehydration (which may thicken the blood and make clots more likely to form), or other medical problems requiring surgery.

Tests and Diagnosis

Several diagnostic tools may be used to effectively diagnose the existence and extent of pulmonary embolism.

Chest X-ray - This is usually used to rule out other conditions that produce similar symptoms.

Lung scan - Also called a "ventilation-perfusion scan," the lung scan uses a radioactive material to evaluate the blood flow through your lungs. You will inhale the radioactive material while a device tracks the material through your lungs. Radioactive material will also be injected into your blood stream so doctors can evaluate the flow of blood. These two studies are often done together because together they provide a more accurate picture of what is happening with the body than on their own.

Spiral (helical) computerized tomography (CT) scan - Instead of a normal CT scan which takes X-ray images from many different angles before combining them into two-dimensional slices, a spiral or helical CT scan rotates around your body to create a three-dimensional image which can detect abnormalities with much greater accuracy and much faster than normal CT scans.

Pulmonary angiogram - A flexible tube or catheter is inserted into a large vein and threaded through your heart into the pulmonary arteries. A special dye is injected into the catheter and then X-rays are taken as the dye spreads through the arteries in your lungs. The pulmonary angiogram is the most accurate way to diagnose pulmonary embolism, but it requires great skill to perform and carries serious potential risks (change in heart rhythm and kidney damage from the dye in those with compromised kidney function). Because of the risks, it is usually only performed when the other methods have failed.

Ultrasounds, MRIs, and D-dimer blood tests are also common diagnostic tools that are used to help diagnose pulmonary embolism.

Treatment

Treatment of pulmonary embolism is primarily aimed at dissolving the clot. This done through thrombolytic or anticoagulant therapy. This is usually done through an intravenous line. The patient will also be maintained on an oxygen therapy regimen to maintain oxygen concentrations until the issue with the lungs is resolved.

Heparin and Coumadin (Warfarin) are common blood thinners and are meant to help prevent any blood clots from forming, but can take up to three days to take effect.

Thrombolytics (clot dissolvers) are usually only used in life-threatening situations because they can cause sudden and severe bleeding. It is hoped that the clots will dissolve on their own.

Surgery may involve clot removal using a thin flexible tube (catheter) threaded through the blood vessels, or a vein filter which will block clots from being carried into your lungs. The latter procedure is usually reserved for those patients who cannot take anticoagulant drugs or when anticoagulant medications are ineffective.

Prevention

To prevent pulmonary embolism requires a focus on preventing the formation of blood clots. Preventative therapy may include:

Ongoing taking of Heparin or Warfarin (Coumadin)

Wearing of graduated compression stockings which help regulate the blood flow through your veins and leg muscles, particularly after surgery. These are also good while traveling.

Pneumatic compression - thigh-high or calf-high cuffs that automatically inflate with air every couple of minutes to massage and stimulate the veins in your legs and improve blood flow

Physical activity - It is important that a patient engage in physical activity as soon as possible after surgery. Physical activity keeps blood flowing and muscles moving thereby preventing development of blood clots. So don't get mad at your nurse for pushing you to get out of bed.

To prevent blood clots while traveling:

Take a walk - About once an hour is sufficient. Just a couple of times up an airplane or train aisle or around the car and a few knee bends will help keep blood moving.

Stretch in your seat - Flex, extend, and rotate your ankles or press your feet against the seat in front of you (start with your toes and work to get your heel against the seat). With your feet on the floor, lift your feet to rest on your toes and then back down. Refrain from sitting for long periods of time with your legs crossed.

Drink plenty of fluids - This seems to be the catch-all cure-all, but in this case keeping hydrated will prevent the development of blood clots. But not all fluids are good for you. Avoid caffeinated drinks and alcohol as they can contribute to fluid loss.

Sources: www.lung.ca (Canadian Lung Association); www.mayoclinic.com; www.theheart.org