A dangerous complication of thoracocentesis

A 19 year old man with no previous medical problems presented with a six day history of breathlessness and left sided chest pain that had started acutely. His respiratory rate was 22 breaths/min, with oxygen saturations of 95% in room air. A chest radiograph showed a large left pneumothorax with slight mediastinal shift (fig 1⇓). Fig 1 Chest radiograph taken at presentation A chest drain that was inserted initially improved his symptoms, but he rapidly deteriorated in the first hour after drain insertion. His breathlessness and pain worsened. He coughed up a large volume of frothy clear yellow sputum. His respiratory rate increased to 35 breaths/min and oxygen saturations fell to 85% on high flow oxygen. Chest radiography was repeated (fig 2⇓). Fig 2 Chest radiograph taken one hour after insertion of a chest drain ### 1 After chest drain insertion for treatment of a pneumothorax, should the fluid at the underwater seal of the bottle oscillate, bubble, or both? #### Short answer The fluid at the underwater seal should oscillate and bubble. #### Long answer After insertion of an intercostal chest drain, the drain should be connected to a drainage system containing a valve mechanism.1 In most cases this will be a bottle with an underwater seal that allows fluid or air to escape, but not enter, the pleural cavity. During inspiration the pressure in the pleural cavity falls, causing an upward movement of fluid (towards the pleural cavity) at the underwater seal. During expiration, the pressure in the pleural cavity rises, which causes downward movement of the fluid. This up …