<prompt> Subcutaneous emphysema may be found in the following conditions:TracheostomyHemilich maneuverChest injuryAll of the above  <response>: Posterior tracheal wall laceration is responsible for emphysema after Percutaneous Tracheostomy. After perforation of the posterior trachea wall, the pleural space can be reached easily. This may result in a pneumothorax. Trauma to chest including after a vigorous Hemilich maneuver can lead to subcutaneous emphysema. 