Pleural effusion

Introduction The thoracic cavity is a closed cavity composed of the parietal pleura and the visceral pleura. The inside is a negative pressure. Under normal circumstances, there is a very small amount (about 1~30 ml) of liquid between the two pleuras. To reduce the friction between the two layers of pleura during respiratory activities, which helps the lungs to contract in the chest cavity. This fluid is produced from the parietal pleura, absorbed by the visceral pleura, constantly circulating in a dynamic equilibrium, and the amount of fluid remains constant. When a certain condition affects the pleura, whether the pleural effusion of the parietal pleura or the rate of absorption of the pleural effusion by the visceral pleura changes, the fluid in the thoracic cavity is increased, which is called pleural effusion (effusion).

Cause

Cause of pleural effusion

Pleural effusion is a clinical sign that causes pleural formation and absorption of pleural fluid, causing excessive water accumulation in the pleura. Under normal circumstances, the parietal pleura continuously produces pleural fluid into the pleural cavity, and the visceral pleura continuously absorbs the draining pleural fluid to achieve a balance between production and drainage recovery. There is always a certain amount of fluid in the chest cavity, but it is not easy to find the general positioning chest or the perspective. There are a small amount of effusion in the pleural cavity of healthy people. For example, when using anterior radiographs after lying on the side, about 12.5% of the people have a small amount of fluid in the chest, and 22.8% of the women can find a small amount of fluid. Children have 4.3% of people have a small amount of pleural fluid.

Hydrothorax can be divided into exudative and leaking properties. There are many causes of exudative, which are summarized into two categories: one is caused by inflammatory lesions, such as infectious inflammation caused by infection of the pleura by bacteria, viruses or fungi, leading to pleural effusion, or due to pulmonary embolism, pancreatitis Non-infectious inflammation such as connective tissue disease causes pleural effusion; the second type is neoplastic, such as cancer in the pleural effusion or metastasis invading the pleural effusion, which can be found in pleural mesothelioma, lung cancer, breast cancer, stomach cancer, etc. . The cause of leakage pleural effusion can be systemic diseases, such as hypoproteinemia, allergic diseases, or diseases of certain organs, such as congestive heart failure, cirrhosis, hepatic amebiasis, thoracic duct rupture. Wait.

an examination

Related inspection

Chest perspective chest MRI

(1) Chest pain: There are abundant sensory nerve fibers on the parietal pleura, either caused by infection of the pleura itself or by nerve fibers. Pleurisy causes chest pain, called pleural chest pain. The pain is often stinging in the inflammation area. After the pain disappears, it becomes painful. Sometimes the pleural pain can be reflected to the abdomen. The pain caused by pleural tumors is mostly dull, persistent, and sometimes very intense. It can be limited or diffuse. Although the pleural fluid is increased, it can not be alleviated.

(2) Dry cough: A reflex cough that may be caused by stimulation of the pleura. If there is inflammation in the lungs at the same time, you may have a cough.

(3) Dyspnea: a, pleural effusion, liquid pneumothorax and pleural tumor can compress the lung tissue or limit the diaphragm muscle movement, because when the effusion occupies the pleural effusion to occupy a certain volume of pleural effusion, the volume is reduced, affecting the lung function, causing breathing difficult. b, chest pain limits breathing movement. C, pleural thickening limits thoracic and lung movements. Dysphagia caused by benign diseases is often mild, and is relieved as the lesions improve; malignant diseases are often more severe and progressively worse.

(4) fever: related to the cause of effusion, combined pleurisy is low fever in the afternoon, often around 38oC, empyema is often high fever, fungal pleurisy and malignant tumors are low or no fever, fever is reduced with decreased pleural effusion .

(5) Extra-pleural symptoms: The pleural effusion caused by heart failure must have symptoms and signs of heart disease.

Differential diagnosis

Differential diagnosis of pleural effusion:

Lung cancer pleural effusion: a common complication of patients with advanced lung cancer, may initially have little effect on quality of life, but as the disease progresses, it may cause symptoms such as difficulty breathing, cough, chest pain, and even worse than the lung cancer itself. . Therefore, the elimination of pleural effusion is a top priority for alleviating the suffering of patients with lung cancer.

Malignant pleural effusion: refers to pleural metastasis of malignant tumors or pleural effusion caused by malignant tumors of the pleura. Infection, pain, and pericardial effusion of cancer are common complications of advanced cancer. The reduction of stress-induced atelectasis, restrictive ventilatory disorder, respiratory failure, and decreased blood volume caused by a large amount of pleural effusion seriously affects the respiratory cycle function and directly threatens the patient's life.

Bloody pleural effusion: refers to the appearance of pleural effusion with obvious blood. More than 15% of the leakage and more than 40% of the exudate can be blood. The red blood cell count is between 5000~100000/l, only 5000~10000/l of red blood cells is needed. The pleural effusion can be made red, and only 1 ml of blood can make 500 ml of pleural effusion bloody. The red blood cells of the gross pleural effusion of the gross eye are >100000/l; the bloody pleural effusion indicates trauma, malignant tumor or pulmonary embolism.

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