What is pulmonary embolism?

PE is a total or partial occlusion of one or more pulmonary arteries, which often arising from deep vein thrombosis(DVT). PE is caused by embolization of a thrombus from leg or pelvic vein that enters the pulmonary artery circulation and blocks a vessel. Pulmonary embolism can be life threatening as it block the blood flow to the lungs. If PE is left untreated, it will lead to:

• Impaired gas exchange
• Alveolar hyperventilation

What causes Pulmonary Embolism?

PE happens when a blood clot (thrombus) of a deep vein of leg (called deep vein thrombosis) detach and travel through the blood vessels to the lungs where it will cause a blockage of the pulmonary artery.

Blockage of the pulmonary artery may be caused by other substances other than blood clots, such as:

• Air bubbles (during neurosurgery)
• Fat (long bone fractures)
• Tumor cells (renal cell carcinoma)
• Parasite eggs (schistosomiasis)
• Septic emboli (acute infectious endocarditis)

Symptoms of Pulmonary Embolism

Sign and symptoms of PE include:

• Dyspnea (shortness of breath)
• Chest pain
• Tachycardia (rapid heart rate)
• Fever
• Cyanosis
• Cough up blood
• Leg pain

Risk factors of Pulmonary Embolism

1. bedrest (specially with legs immobilization)
2. Surgery (especially orthopedic surgery)
3. Severe trauma (burns or fractures)
4. Congestive heart failure
5. Disseminated cancer (e.g. Myeloma)
6. Disorders of hypercoagulability
7. Using oral contraceptives
8. Smoking

Treatment of Pulmonary Embolism

Pulmonary embolism may be treated using oral anticoagulation or thrombolytic.

1. Anticoagulants prevent the formation of new clots, and thus inhibit blood coagulation, but they do not dissolve the already existing clots. Examples of Anticoagulants include:
   • Heparin (including low molecular weight heparin)
   • warfarin
2. Thrombolytics such as alteplase and tenecteplase, Act by dissolving the intravascular blood clots.