4.10
폐색전증 I: 소개
혈전, 또는 혈전은 섬유소, 혈소판, 적혈구로 이루어진 반고체 덩어리입니다. 혈관 내에서 형성되면 혈류를 막을 수 있는데, 이를 혈전증이라고 합니다. 혈전 일부가 떨어지면 색전이 되어 멀리 떨어진 혈관을 막을 수 있습니다. 이 현상이 폐동맥에서 발생하면 폐색전증(PE)…
혈전 또는 혈전은 혈관 내에 형성되어 혈류를 부분적으로 또는 완전히 차단할 수 있습니다. 이 상태를 혈전증이라고 합니다.
혈전 일부가 떨어져 혈류를 통해 이동하면 색전이 됩니다.
색전이 폐동맥에 걸리면 폐색전증(PE)으로 이어질 수 있습니다. 대부분의 경우, 색전은 다리 깊은 정맥에 생긴 혈전에서 시작되며, 이를 심부 정맥혈전증이라고 합니다.
PE의 발병은 정맥정혈, 과응고, 내피 손상 세 가지 요인인 Virchow's triad로 설명되며, 이 세 가지 요인이 혈전 형성에 기여합니다.
정맥정체는 정형외과 수술 후나 장기간 앉아 있는 경우(예: 장시간 비행 중)에서 발생할 수 있습니다.
항트롬빈 III 결핍, 임신, 에스트로겐 함유 피임약 사용과 같은 질환으로 인해 과응고가 발생할 수 있습니다.
내피 손상은 외상이나 중심정맥 카테터 삽입술로 인해 발생할 수 있습니다.
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Q1: What is the difference between a thrombus and an embolus?
A thrombus is a blood clot that forms within blood vessels and can block blood flow, a condition called thrombosis. An embolus forms when part of the thrombus breaks away and travels through the bloodstream. If the embolus lodges in a pulmonary artery, it causes a pulmonary embolism.
Q2: What is deep vein thrombosis and how does it relate to pulmonary embolism?
Deep vein thrombosis (DVT) is a blood clot that forms in the deep veins of the legs. In most cases, the embolus that causes pulmonary embolism originates from a thrombus in these deep leg veins. DVT and PE together are considered part of the same disease process called venous thromboembolism.
Q3: What are the three factors in Virchow's triad that contribute to blood clot formation?
Virchow's triad includes venous stasis, hypercoagulability, and endothelial injury. Venous stasis occurs when blood flow slows due to immobility from surgery or prolonged sitting. Hypercoagulability results from conditions like antithrombin III deficiency or pregnancy. Endothelial injury may be caused by trauma or catheterization.
Q4: What causes venous stasis and who is at risk?
Venous stasis occurs when blood flow becomes stagnant due to immobility. Risk factors include prolonged bed rest after orthopedic surgery, extended plane flights, heart failure, obesity, pregnancy, and catheter use. Any condition limiting movement can slow blood circulation in the veins.
Q5: What conditions increase blood coagulability and raise pulmonary embolism risk?
Hypercoagulability can be inherited, such as factor V Leiden or protein C/S deficiency, or acquired through malignancy, oral contraceptives, pregnancy, or inflammatory disorders. These conditions increase the tendency of blood to clot, raising the risk of thrombus formation and subsequent pulmonary embolism.
Q6: How can endothelial injury contribute to pulmonary embolism development?
Endothelial injury damages the inner lining of blood vessels, activating clotting pathways that promote thrombus formation. Trauma, surgery, or prior thrombosis can cause this vessel wall damage. When a resulting clot dislodges and travels to the lungs, it causes pulmonary embolism.
Q7: Why are hospitalized and cancer patients at higher risk for pulmonary embolism?
Hospitalized and cancer patients face increased risk due to immobility, inflammation, and procoagulant states that promote blood clotting. These factors align with Virchow's triad mechanisms: reduced blood flow, increased clotting tendency, and vessel damage. Understanding these mechanisms supports early detection and prevention strategies in chronic obstructive pulmonary disease clinical contexts.