 And thank you for watching Nursing School Explained. Today's topic is pulmonary embolus or PE. So let's look at the pathophysiology behind a PE. So remember that the thrombus is the blood clot that is on the move, where an embolus is a blood clot that has become stagnant or dislodged somewhere. So for a pulmonary embolus that is a thrombus that is now dislodged in the pulmonary artery. It can, so it's a thrombus, but it can also be a fat or air embolus or a tumor. So basically what a fat embolus is that usually happens after long bone fractures when let's say the femur breaks, bone marrow is released, some fat enters the bloodstream and then it can become dislodged in the lungs. Where an air embolus is basically the mishandling of an IV line. So now air has gotten the patient's IV line, it travels up the vasculature and then this air does not allow blood flow to the lungs and their flow for it becomes obstructed. And certainly tumors can cause that as well. But the most common cause of pulmonary embolus is DBT, deep vein thrombosis that becomes dislodged and is now entered the pulmonary artery and is causing some major problem with ventilation and perfusion. Other causes are atrial fibrillation. Remember that when the atria they just quiver and there's a lot of swishing around of the blood in the atria, the patient is more prone to clots. It can come, this becomes dislodged and then get into the pulmonary artery as well as pelvic veins after surgery. So any kind of abdominal surgery puts the patient at higher risk for a clot that forms in the pelvic veins.