Decompression of the chest is a life-saving invasive procedure for tension pneumothorax, trauma-associated cardiopulmonary resuscitation or massive haematopneumothorax that every emergency physician or intensivist must master. Particularly in the preclinical setting, indication must be restricted to urgent cases, but in these cases chest decompression must be executed without delay, even in subpar circumstances. The methods available are needle decompression or thoracentesis via mini-thoracotomy with or without insertion of a chest tube in the midclavicular line of the 2nd/3rd intercostal space (Monaldi-position) or in the anterior to mid-axillary line of the 4th/5th intercostal space (Bülau-position). Needle decompression is quick and does not require much material, but should be regarded as a temporary measure. Due to insufficient length of the usual 14-gauge intravenous catheters, the pleural cavity cannot be reached in a considerable percentage of patients. In the case of mini-thoracotomy, one must be cautious not to penetrate the chest inferior of the mammillary level, to employ blunt dissection techniques, to clearly identify the pleural space with a finger and not to use a trocar. In extremely urgent cases opening the pleural membrane by thoracostomy without inserting a chest tube is sufficient in mechanically ventilated patients. Complications are common and mainly include ectopic positions, which can jeopardise effectiveness of the procedure, sometimes fatal injuries to adjacent intrathoracic or - in case of too inferior placement - intraabdominal organs as well as haemorrhage or infections. By respecting the basic rules for safe chest decompression many of these complications should be avoidable.
Keywords: Chest decompression; Pneumothorax; Thoracentesis; Thoracic injuries; Thoracostomy.