After using an injection of local anesthetic, the needle goes through the skin, between the ribs and into the pleural space.
A sample of fluid is taken and sent to the laboratory for testing. If you have a closed pleural biopsy the same process is used to remove tissue samples from the inside lining of the chest wall.
Finally, the needle is taken out and sometimes may require stitches (if a pleural biopsy is taken) and a dressing is put over the area and then a chest X-ray may be needed.
This procedure will require an anesthetic: Local anesthetic and, sometimes, sedation for your procedure. Local anesthesia is generally very safe, but any anesthetic can have side effects or complications.