Pulmonary Embolism (PE) is an emergency that kills 100,000 Americans and endangers 900,000 more annually. (CDC, 2015). 25% of those who develop pulmonary embolism die suddenly before experiencing any symptoms. And, 10 to 30 percent of patients who develop pulmonary embolism die within one month of their diagnosis (CDC, 2015; Tidy & Hartree, 2014). Men are at a slightly higher risk than women, and one’s risk for developing pulmonary embolism rises significantly with age (Thompson, 2016a).
Patients undergoing major surgery are at an especially high risk for developing pulmonary embolism. But, it is critically important that doctors assess all hospitalized patients for their risk of developing pulmonary embolism and take preventative measures. Prevention, prompt diagnosis and proper treatment of this potentially deadly condition are the keys to saving lives.
What is pulmonary embolism?
A pulmonary embolism is an obstruction in an artery of the lung. The obstruction is most often caused by deep vein thrombosis (DVT) (Tidy & Hartree, 2014). When DVT occurs, a piece of a blood clot – called an embolus – breaks away from its origin in the deep veins of the leg and travels through the body inside a vein. Eventually, the clot or clots become lodged in a large artery inside the lung known as the pulmonary artery.
Less often, pulmonary emboli are formed from blood clots developing in veins located in a part of the body other than the legs, such as the pelvis, an arm, or the heart.
Pulmonary emboli can vary in size and number; for example, the condition may consist of numerous small clots or one big clot. A large clot near the center of the lung is called massive pulmonary embolism. A massive pulmonary embolism can cause persistent low blood pressure, a condition also known as hypotension, and shock.
Rarely, a pulmonary embolus can be caused by other factors such as
- fatty material from bone marrow (occurs if a large, long bone is broken),
- impure injection material (e.g., from drug abuse) or other foreign material,
- a broken-off piece of a cancerous tumor,
- amniotic fluid during pregnancy or childbirth, or
- large air bubbles.
What causes pulmonary embolism?
Some people have a higher risk of developing pulmonary embolism, including those who have a history of blood clots or people with inherited thrombophilia – a genetic disorder that causes blood to clot more readily (Chen, 2015; Thompson, 2016b). Other common risk factors include undergoing major surgery, certain preexisting medical conditions (e.g., pregnancy, smoking, cancer), or the use of particular medications (e.g., birth control pills, hormone replacement therapy, tamoxifen; Thompson, 2016b).
Pulmonary embolism can cause numerous problems including, but not limited to, collapsing, cardiac arrest, heart failure, and recurrent pulmonary embolism (Tidy & Hartree, 2014).