A thoracentesis, or pleurodesis, is an operation performed to determine the nature of a pleural effusion or to treat a pleural effusion or pneumothorax. If blood is withdrawn during a pleurodesis, there is a risk of damage to lung tissue, blood vessels such as intercostal vessels, etc. The withdrawal of blood during a pleural cavity puncture may be caused by improper handling, which may damage lung tissue or blood vessels in the chest cavity or intercostal vessels, and if the bleeding is not significant, the bleeding can usually be stopped on its own. If the injury results in a large amount of bleeding, hypotension, hemorrhagic shock, etc., immediate blood transfusion, fluid transfusion, closed drainage, and if necessary, open thoracic exploration to stop bleeding are required. After the patient has undergone pleural cavity puncture, he needs to observe whether there is any severe cough, shortness of breath, whether there is any blood or fluid leakage from the puncture point, and other symptoms.