Source: Rachel Liu, BAO, MBBCh, Emergency Medicine, Yale School of Medicine, New Haven, Connecticut, USA Tube thoracostomy (chest tube placement) is a procedure during which a hollow tube is inserted into the thoracic cavity for drainage of fluid or air. Emergency chest tube insertion is performed for definitive treatment of tension pneumothorax, traumatic hemothorax, large-volume pleural effusions, and empyemas. Irrespective of the cause of air and fluid accumulation in the pleural space, the drainage relieves lung compression and enables lung re-expansion. In pneumothorax, air accumulation in the pleural cavity separates pleural layers, which prevents lung expansion during the respiration. Abnormal fluid accumulation, such as in case of hemothorax or empyema, causes separation of the visceral pleura that adheres to lung tissue from the parietal pleura that forms the lining of the chest cavity. The uncoupling of the pleural layers leads to disconnection of chest wall movement from the lung movement, causing respiratory distress. In addition, excessive pressure from overwhelming amounts of air or fluid in the pleura may push the mediastinum away from the central chest, causing inability of blood to return to the heart. In the trauma setting, a chest tube may not only treat a hemothorax but also allow monitoring of the bleeding rate. Massive hemothorax or continued brisk bleeding necessitates progression to a surgical thoracotomy, which is the opening of the chest wall to seal bleeding sites. Chest tubes consist of clear plastic with a radiopaque strip running along their length, and fenestrations along the tip of the tube. Tube sizes vary from 12 to 42 French (Fr), with the smaller sizes used for pediatric cases. A size 36 Fr or larger is standard size to be used for hemothorax and empyema drainage.