What happens pulmonary thromboembolism?
Pulmonary embolism (PE) occurs when a blood clot gets lodged in an artery in the lung, blocking blood flow to part of the lung. Blood clots most often start in the legs and travel up through the right side of the heart and into the lungs.
What is the pathophysiology of VTE?
Causes. VTE occurs in the veins that carry blood to your heart. A deep vein thrombosis may occur if the flow of blood slows down in your body’s deep veins, if something damages the blood vessel lining, or if the makeup of the blood itself changes so that blood clots form more easily.
How does pulmonary embolism affect physiology?
Complete obstruction of a pulmonary artery by an embolus causes an increase in anatomic dead space. In contrast, incomplete obstruction of a pulmonary artery increases physiological dead space, ie, ratios of ventilation to perfusion increase. Increased dead space impairs the efficient elimination of carbon dioxide.
What is the most common origin of a pulmonary thromboembolism?
Pulmonary embolism is caused by a blocked artery in the lungs. The most common cause of such a blockage is a blood clot that forms in a deep vein in the leg and travels to the lungs, where it gets lodged in a smaller lung artery. Almost all blood clots that cause pulmonary embolism are formed in the deep leg veins.
What is venous thromboembolic?
Venous thromboembolism (VTE), a term referring to blood clots in the veins, is an underdiagnosed and serious, yet preventable medical condition that can cause disability and death.
What 3 elements are thought to cause a VTE?
In 1884, Rudolph Virchow first proposed that thrombosis was the result of at least 1 of 3 underlying etiologic factors: vascular endothelial damage, stasis of blood flow, and hypercoagulability of blood.
What is the pathophysiological etiology and rationale for a pulmonary embolism?
PE occurs when deep venous thrombi detach and embolize to the pulmonary circulation. Pulmonary vascular occlusion occurs and impairs gas exchange and circulation. In the lungs, the lower lobes are more frequently affected than the upper, with bilateral lung involvement being common.
Why does PE cause respiratory alkalosis?
Thus, most patients with PE present with a lower than normal arterial PCO2 and respiratory alkalosis because of an increased total minute ventilation. Limited data suggest that the increased total minute ventilation occurs because of reflex stimulation of irritant and juxta capillary sensors in the lung.
What is massive pulmonary thromboembolism?
Massive pulmonary embolism is defined as obstruction of the pulmonary arterial tree that exceeds 50% of the cross-sectional area, causing acute and severe cardiopulmonary failure from right ventricular overload.