"Lung" with Xiaoke's embolism, understand the "embolism" of pulmonary thromboembolism

Author: Sun Jiaying, Associate Chief Physician and Associate Professor, The Fourth Affiliated Hospital of China Medical University

Liu Chong Shengjing Hospital Affiliated to China Medical University

Reviewer: Gu Xiu, Chief Physician and Professor of the Fourth Affiliated Hospital of China Medical University

Pulmonary embolism, a medical term, refers to a series of diseases or clinical syndromes caused by various emboli blocking the pulmonary artery and its branches. The components of these emboli are diverse, including but not limited to blood clots, fat, amniotic fluid, air, and tumor cells. Among them, blood clots, as the most common type of emboli, account for the vast majority of the causes of pulmonary embolism. Pulmonary embolism caused by thrombus emboli is specifically called pulmonary thromboembolism.

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The clinical manifestations of pulmonary thromboembolism vary, but dyspnea is undoubtedly the most common symptom. Many patients will feel shortness of breath when they develop the disease, as if the chest is being pressed by a heavy object. In addition, some patients may also have atypical symptoms such as chest pain, hemoptysis, and cough. Although these symptoms are not as significant as dyspnea, they should not be ignored. What is more serious is that if pulmonary thromboembolism is not treated promptly and effectively, it may cause a series of serious complications, such as pulmonary hypertension, cor pulmonale, heart failure, etc. These complications will seriously threaten the patient's life safety.

Most of the thrombi in pulmonary thromboembolism originate from the venous system or the right heart. In particular, the proximal deep veins of the lower limbs account for 50% to 90% of the thrombi. This is because the lower limb veins are far away from the heart, the blood return rate is relatively slow, and the effect of gravity makes it easier for thrombi to form in the lower limb veins. Once these thrombi break off and flow into the pulmonary artery with the blood, pulmonary thromboembolism will occur.

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In addition to the veins of the lower limbs, any factor that can increase the risk of thrombosis may be a cause of pulmonary thromboembolism. Clinically, fractures, long-term bed rest, obesity, pregnancy, long-term oral contraceptives, severe trauma, and tumors are all considered high-risk factors for pulmonary thromboembolism. These factors can cause the patient's blood to be in a hypercoagulable state, thereby increasing the risk of thrombosis. In order to assess the patient's likelihood of developing deep vein thrombosis or pulmonary thromboembolism, doctors usually use a venous thrombosis risk score for quantitative assessment.

Once pulmonary thromboembolism is suspected, the patient should seek medical attention for screening as soon as possible. During the screening process, the doctor may find changes in biochemical indicators such as elevated D-dimer, hypoxemia, and abnormal myocardial injury markers. At the same time, electrocardiograms and cardiac ultrasound may also show abnormal manifestations such as pulmonary hypertension and increased right heart load. In order to further confirm the diagnosis of pulmonary thromboembolism, the doctor may recommend that the patient undergo pulmonary artery enhanced CT, pulmonary artery enhanced MRI, radionuclide pulmonary ventilation perfusion scanning or pulmonary angiography. Among them, pulmonary artery enhanced CT has become the most widely used clinical diagnosis method because of its non-invasive, fast and accurate characteristics. It can clearly show the thrombotic lesions in the pulmonary artery and its main branches, providing a strong basis for the diagnosis of pulmonary thromboembolism.

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In terms of treatment, anticoagulant therapy is the basis for the treatment of pulmonary thromboembolism. The use of anticoagulants can effectively inhibit the further formation and development of thrombi and reduce the recurrence rate of pulmonary thromboembolism. Commonly used anticoagulants include unfractionated heparin, low molecular weight heparin, fondaparinux sodium, warfarin, dabigatran etexilate, rivaroxaban, etc. Some critically ill patients also need thrombolytic therapy. Anticoagulant therapy generally needs to be maintained for at least 3 months, and the specific course of treatment needs to be adjusted according to the patient's specific situation. For some patients, such as those with a large local thrombus load or those who are not suitable for anticoagulant therapy, doctors may consider surgical treatment in interventional or vascular surgery, such as filter placement, local aspiration, and thrombectomy. These surgical methods can quickly remove thrombi in the pulmonary artery, alleviate the patient's symptoms, and improve the quality of life. However, it should be noted that during surgical treatment, close attention should be paid to complications such as bleeding in patients to ensure the safety and effectiveness of treatment.

In the diagnosis and treatment of pulmonary thromboembolism, it is crucial to identify high-risk patients and conduct risk stratification. By comprehensively evaluating the patient's clinical manifestations, auxiliary examinations, and venous thrombosis risk scores, doctors can accurately judge the severity of the patient's condition and prognosis. For high-risk patients, early detection and intervention should be carried out, and active and effective treatment measures should be taken to reduce the incidence and mortality of pulmonary thromboembolism. At the same time, strengthening patient health education and raising public awareness and attention to pulmonary thromboembolism are also important means to prevent pulmonary thromboembolism.

In short, pulmonary thromboembolism is a disease that seriously threatens human health. By understanding its etiology, clinical manifestations, diagnosis and treatment, we can better prevent and treat pulmonary thromboembolism and protect the life safety and health of patients.