Thoracentesis is one of the frequently applied operations in cardiothoracic surgery and respiratory medicine. Mastering strict indications, there are less complications after the operation, but there may still be some adverse reactions after the end of puncture. After thoracentesis, continue to observe for 30-60 minutes. The main points to note are: i. Rest in bed, give oxygen and other treatments, give cardiac monitoring if necessary, and closely observe vital signs. Close observation of the patient for pallor, sweating, dizziness and drop in blood pressure, etc. Such conditions are likely to be pleural reactions, which should be treated promptly and epinephrine applied if necessary. Third, observe whether the drainage tube is unobstructed, observe the color of the drainage fluid, record the drainage flow, puncture and bleed air and fluid should not be too much or too fast, otherwise mediastinal displacement and diplopia pulmonary edema may occur. Once the above situation occurs, the drainage tube should be temporarily clamped, and promptly give oxygen, diuretic, epinephrine application and other corresponding treatment. Fourth, change the fluid in the drainage bottle regularly to keep the incision and drainage tube sterile.