Blockage of Lung Arteries

Pulmonary emboli or blood clots in the lungs

The arterial blood (oxygen-rich blood) supply to the lungs via the pulmonary artery or one of its branches can be blocked by matter such as a blood clot (most common), fat, air, tumor (abnormal growth) tissue, bone marrow, amniotic fluid (fluid in the womb), or foreign substances. This is called a pulmonary embolus (plural emboli).

Sudden onset

One or multiple symptoms

Cough -- may be blood-tinged

Shortness of breath

Chest pain may be worse with breathing or coughing

Pain may be on one side and may worsen with bending forward.

Anxiety and restlessness

Person may faint (syncope)

Sweating

Wheezing sound when breathing in or out

Rapid shallow breaths

Bluish coloration of the lips or skin (cyanosis) due to lack of oxygen in the blood (hypoxia)

Rapid, pounding, or Racing Heart rate

Edema in the legs

Pain in the back of the legs

Joint pain

Dizziness

Pain in the pelvic area

Sometimes no symptoms appear

Sudden death may occur

Deep Vein Thrombosis (DVT) -- blood clots or thrombi sometimes form in the leg veins (carrying oxygen-poor blood) and occasionally dislodge (embolize) from the walls of the veins, traveling through the blood stream into the right side of the heart, then to the pulmonary artery, where they block the blood supply to that particular section of the lung. This section of lung then undergoes an infarction (i.e., it dies).

Emboli can also arise from clots in the right side of the heart.

Pieces of tumors invading the circulatory system, fat, air, and other foreign substances can also enter the blood stream and block the arteries supplying different sections (i.e., 5 lobes) of the lungs.

Hypercoagulability -- increased tendency for clot formation is seen in certain conditions and with certain medications and drugs.

95% cases of Pulmonary Embolism are due to DVT.

History:

Symptoms
Illnesses
Surgeries
Habits
Family history
Medications
Allergies

Medical exam:

Rapid heart (tachycardia) and respiratory rate (tachypnea)
Cyanosis
Low Blood Pressure
Doctor may (using stethoscope) hear decreased breath sounds over the infarcted area, wheezing, and friction rub (like sandpaper rubbing together).
Distended neck veins
Galloping heart sound
Tenderness or lump in the back of the leg (Deep Vein Thrombosis)

Tests:

Arterial blood gas -- may show hypoxia.
Oxygen levels may be normal.
Other blood tests may be normal, but levels of Antithrombin III (measures risk for clot formation) may provide valuable information.
Chest X-Ray may be normal or may show wedge-shaped area, one-sided elevation of the diaphragm (muscle that pulls air into the lungs), fluids, or collapse.
Electrocardiogram (ECG) (records the electrical activity of the heart) may show characteristic patterns.
To find the source of the clot or infarcted area in the lungs, the following tests may be performed:

Pulmonary (lung) scanning or ventilation/perfusion scan (V/Q scan) will show the infarcted segment.

Angiography -- injection of a dye into arterial supply will identify the location of the blockage.

Echocardiography -- sound used to find the clot in the heart.

Spiral CAT scan -- computer generates picture

Venous duplex scanning, impedance plethysmography, and Doppler Ultrasound -- look for clots inside the veins (legs, thighs, etc).

Prolonged bed rest -- after surgery, elderly with fractures, or illnesses

Stroke

Heart Failure

Pregnancy

Obesity

Cancers

Long air flight travel

Advanced age

Diabetes

Poor circulation to the legs due to Peripheral Vascular Disease

Burns

Hospitalization

Oral contraceptives and estrogen-containing medications

Edema or swelling in the legs due to fluid

Pelvic fractures (pelvis is the bony region between the hips)

Hospitalization

Depends on the severity

Bed rest

Administer oxygen or fluids as needed

Pain medication if needed

Attempt to dissolve the clot (thrombolysis) and prevent further clot formation with intravenous (inside the veins) use of heparin and warfarin (pill form).

Potent clot busters such as streptokinase, urokinase, and TPA are also beneficial but less available and more expensive.

In patients unable to receive thrombolytic therapy or are doing very poorly, surgical removal of the embolus (embolectomy) may be beneficial.

Some patients with repeated emboli to the lungs or those who cannot take anticoagulants (clot busters) may need a surgical procedure to place an umbrella-like filter in the inferior vena cava (major vein to the heart) to catch the incoming clots.