In normal people, there is a small amount of fluid in the pleural cavity, which plays a lubricating role in respiratory movements. When there is a large increase of fluid in the pleural cavity, it is called pleural effusion. Pleural effusion can be divided into leakage and exudate, benign and malignant, and also bloody, purulent and celiac according to its nature. At present, the more common ones are mostly pleural effusions caused by infections (especially tuberculous pleurisy is the most common) and malignant tumors. Most benign pleural effusions are pale yellow clear pleural fluid, similar to beer-like. Most malignant pleural effusions are hemorrhagic pleural fluid. A small amount of fluid (<300ml) is usually asymptomatic. x-rays may show blurred and blunted rib diaphragm angle. Above medium amount, the patient may feel chest tightness and dyspnea, and arc-shaped shadow is visible on x-ray. Ultrasonography is more reliable for locating pleural effusion and determining the depth of needle entry during thoracentesis. The differential diagnosis of pleural effusion is mainly the extraction of pleural fluid for examination and the examination of the primary lesions in the chest and lungs. In addition to active treatment of the primary lesion, pleural aspiration, closed drainage of the chest cavity, thoracoscopic biopsy and pleural fixation can be used for pleural effusion, and for patients with chronic prolongation and formation of encapsulated abscess chest, pleurodesis is also required. The following is a brief explanation of some common problems. 1.What are the methods of pleural fluid extraction? Can it be done on an outpatient basis? The main method of pleural fluid extraction is thoracentesis, which can be performed on an outpatient basis. For patients with abscess chest, malignant pleural fluid and combined pneumothorax, closed thoracic drainage may be required. For patients with unclear diagnosis and the need for pleural biopsy, pleural fluid can be aspirated while performing thoracoscopy to reduce the occurrence of pleural adhesions or even encapsulated pustules. 2.Is it painful to aspirate pleural fluid? What complications can occur? The thoracic puncture and aspiration is local anesthesia, and generally there is no significant pain. The main complications are: 1, peripheral tissue injury: pneumothorax, hemorrhage, transverse septum and abdominal organ injury; 2, pleural reactive shock; 3, chest infection; 4, protein loss; 5, electrolyte disorders; 6, pulmonary edema; 7, pleural fluid embolism. 3.How much pleural fluid should be drawn at one time? The first time the pleural fluid is pumped no more than 600-800ml, and each time thereafter no more than 1000ml, it can be pumped 2-3 times a week, which can be increased appropriately if a slow release device is used. In the case of thoracoscopic surgery, because the chest cavity is open, gas can enter quickly to avoid too rapid lung reopening, and basically there is no limit to the amount of fluid, and the majority of the pleural fluid can be aspirated. 4.What symptoms will occur during the process of chest fluid aspiration? How to deal with it? During the process of thoracentesis, the patient should be closely observed. If dizziness, panic, cold sweat, pallor, chest tightness, chest pain, violent cough and difficulty in breathing occur, the operation should be stopped immediately. Let the patient lie flat, administer oxygen and give further resuscitation treatment according to the situation. 5.Is it normal to have blood in the chest water after puncture of pleural effusion? During the puncture process, the chest wall may be damaged and it is normal to have slight blood in the pleural fluid, which generally does not require special treatment. After puncture, the patient's blood pressure and general condition should be observed, and serious bleeding should be detected and treated in a timely manner. Sometimes the first clear yellowish pleural fluid will turn into light bloody pleural fluid when the chest fluid is drawn for the second time. 6.Which patients is closed chest drainage suitable for? What are the contraindications? Applicable to: spontaneous, traumatic, secondary pneumothorax, acute and chronic abscess chest, pneumothorax, malignant effusion. Contraindications: 1. Leaky fluid; 2. Patients with poor general condition and cardiopulmonary insufficiency. (However, cardiopulmonary insufficiency due to massive pleural effusion should be decided on a case-by-case basis.) 7.What are the precautions to prevent infection? When operating, strictly follow the principles of aseptic operation.