An embolus is a foreign material blocking a blood vessel. When it happens in the lung, the embolus can block one or more vessels and block the blood flow to the lung. If the pulmonary embolus affect a blood vessel supplying a large area of the lung, it can be very serious or fatal. Onset may be sudden. PE may be caused by blood clots, air bubbles, fat globules, and tumor clumps.
Factors Contributing
1.Prolonged immobilization, such as air travel, and bed rest after surgery, which may cause deep vein thrombosis, leading to PE.
2. Obesity
3. Smoking
4. Pregnancy- the weight of the uterus on the big vessels in the pelvis can decrease the blood flow back to the heart.
5. Oral contraceptives- which increases clotting factors in the blood.
6. Hormone replacement therapy after menopause
7. Trauma or fracture of large bones- pieces of fat and bone can act as a clot.
8. Orthopedic procedures and prolonged surgery
9. Other medical conditions, such as hypertension, congestive heart failure, chronic obstructive pulmonary disease.
Symptoms
Difficulty in breathing, increased respiratory rate, wheezing, cough, chest pain, bloody sputum, and bluish discoloration and low blood pressure in massive PE.
Diagnosis
History of sudden onset chest pain. On examination, the lung exam may show increased respiratory rate and wheezing maybe present. Leg swelling may be present in deep vein thrombosis. Chest xray may be normal. Chest CT may be positive. Labwork may show plasma d-dimer enzyme elevated. Arterial blood gases may show elevated carbon dioxide and decreased oxygen. Venous ultrasound can diagnose deep vein thrombosis. Lung scans or Ventilation-Perfusion scan is diagnostic. Pulmonary Angiogram is an test where radio opaque dye is injected into the pulmonary artery, and shows a blockage of the artery.
Treatment
Anticoagulation- This is usually done with medications such as heparin, lovenox temporarily and for long term anticoagulation, coumdain is used. The length of treatment varies, usually at least 6 months but can be life-long.
Thrombolytics dissolve the clot. It is usually used in hemodynamically unstable patients.
Surgical removal of the clot is also done sometimes.
Vena caval filters prevent clots from reaching the lung.
Other supportive treatment includes antiinflammaotry drugs ot treat pain, supplemental oxygen if needed, treating right heart failure if present, volume loading if blood pressure is low.
Prevention
High risk patients must be identified. Mini dose heparin and compression stockings are used as preventative measures. Reducing risk factors like smoking and obesity. |
