Pulmonary embolism is the blockage of a lung (pulmonary) artery or one of its branches by one (pulmonary embolism) or more (pulmonary emboli) blood clot(s). Common symptoms include shortness of breath, chest pain, rapid heart rate, and a cough producing blood-tinged sputum.
Certain conditions place patients at risk to form blood clots such as bed rest, a history of previous blood clot formation, advancing age, stroke, paralysis of the lower extremities, fractures or broken bones in the legs, hip fractures, the use of birth control pills, heart failure, conditions that cause the blood to become "thick" or at a higher risk to clot and many types of surgeries especially orthopedic (surgery on the bones) surgeries. The most common place in the body to form blood clots are in the deep veins of the legs or pelvis. These blood clots may break off and travel through the blood stream to the lungs.
Smaller clots are treated with oxygen and blood thinners. Larger clots or multiple clots are more dangerous and can be deadly. Seriously ill patients may require a breathing (endotracheal) tube and a breathing machine (mechanical ventilator) in addition to blood thinners. Sometimes a filter is surgically placed in the main vein in the abdomen (inferior vena cava) to prevent further clots from getting to the lung.
Clots tend to form in the deep veins of the legs and pelvis in bed-ridden patients. This includes most ICU patients. Measures are therefore taken in almost all ICU patients to prevent the development of blood clots. These measures include use of elastic stockings, air compression stockings and/or small doses of blood thinners.
Related LinksNational Library of Medicine
The National Library of Medicine website describes the essential features of pulmonary embolism.