Question: Ive heard that a chest tube exchange is coded 49423 (Exchange of previously placed abscess or cyst drainage catheter under radiological guidance [separate procedure]). Which crosswalk should I use? New Hampshire Subscriber Answer: Use code 32551 (Tube thoracostomy, includes water seal [e.g., for abscess, hemothorax, empyema], when performed [separate procedure]) to crosswalk to the anesthesia code for a chest tube insertion (00520, Anesthesia for closed chest procedures; [including bronchoscopy] not otherwise specified). This is a better code selection than 49423. A chest tube insertion is in the pleural space between the pleural membranes that surround the lungs and the chest cavity. The code you suggest is intraperitoneal -- within the peritoneal cavity, the area that contains the abdominal organs.