Thoracentesis, also known as thoracocentesis (from θώραξ 'chest, thorax', and κέντησις 'pricking, puncture'), pleural tap, needle thoracostomy, or needle decompression (often used term), 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 administ... Wikipedia