Renata Gutierrez is a 34-year-old female client who was brought to the Emergency Department, or ED, by her partner, with complaints of shortness of breath, chest pain, and coughing up blood-tinged sputum. The triage nurse informs you that Ms. Gutierrez delivered a healthy full term baby by cesarean section one week ago. She has no other significant past medical history.
A pulmonary embolism, or PE, occurs when an embolus, which is a small mass that could be a blood clot, a piece of plaque, fat or air, becomes lodged in the pulmonary artery and obstructs the pulmonary circulation. Most often the embolus is a blood clot associated with deep vein thrombosis, or DVT, which is when a clot forms in a large vein, usually in the leg or pelvis. The clot becomes a venous thromboembolism, or VTE, when it breaks off and travels up the inferior vena cava to the right atrium, into the right ventricle, and finally into the pulmonary artery. This causes decreased blood flow to the lung tissue and impaired oxygenation.
Factors that increase the risk of a pulmonary embolism are summarized in Virchow’s triad, which include slowed blood flow, or venous stasis, hypercoagulation, meaning the blood is more likely to form clots, and damage to the endothelial lining of a blood vessel. Venous stasis can occur because of prolonged immobility like during a severe illness or after surgery, when an enlarged uterus compresses the nearby veins during pregnancy, or due to long-haul travel. Hypercoagulability can be caused by clotting disorders, use of oral contraceptives, smoking, and it occurs normally during pregnancy. And lastly, damage to the endothelial cell lining of a blood vessel can be the result of trauma or surgery.