The operation steps of thoracentesis are choosing position, positioning anesthesia, puncture and drainage, fixation; precautions are puncture site, drainage volume and so on.
1. Selection of body position: the examinee is instructed to sit on the chair in reverse, with the forearms on the back of the chair and the head resting on the forearms.
2. Positioning anesthesia: locate the puncture point by means of ultrasound and percussion, and then use lidocaine for local anesthesia.
3. Puncture and drainage: make an incision of about 2mm at the puncture point, the puncture needle slowly enters the thoracic cavity, and the success is indicated by the presence of fluid in the retraction, and the specimen is retained for laboratory tests, such as routine, biochemistry, and so on.
4. Fixation: fix the puncture tube and drain the pleural fluid (fluid that stays in the chest cavity) as needed.
Precautions include choosing the lower edge of the upper rib when puncturing; draining the pleural fluid with no more than 600 ml for the first time and no more than 1,000 ml thereafter; and stopping the puncture when discomfort occurs during the procedure.
Thoracentesis needs to be performed by a specialized physician, and any discomfort should be treated promptly.