Thoracentesis /ˌθɔːrəsɪnˈtiːsɪs/, also known as thoracocentesis  'chest, thorax', and κέντησις  'pricking, puncture'), pleural tap, needle thoracostomy, or needle decompression , is an invasive medical procedure to remove fluid or air from the pleural space for diagnostic or therapeutic purposes. A cannula, or hollow needle, is carefully introduced into the thorax, generally after administration of local anesthesia. The procedure was first performed by Morrill Wyman in 1850 and then described by Henry Ingersoll Bowditch in 1852.