ABSTRACT
The indications for insertion of a chest drain include the drainage of established or threatened collections of air, blood, fluid or pus from the pleural cavity. According to guidelines produced by the British Thoracic Society, a simple, spontaneous pneumothorax can be aspirated without the need for a chest drain. However, any patient developing a pneumothorax while receiving positive pressure ventilation should have a chest drain inserted. Without chest drainage, 50% of these will develop into a tension pneumothorax. A tension pneumothorax requires immediate decompression. For patients in extremis a cannula in the 2nd intercostal space in the mid-clavicular line of the affected side will reverse the life-threatening mediastinal compression while preparations are made for chest drainage. A patient with fractured ribs who requires intubation and positive pressure ventilation may need to have a chest tube inserted prophylactically. This is indicated particularly before interhospital transfer or prolonged anaesthesia for associated injuries; under these circumstances a developing tension pneumothorax is likely to be discovered late. If the patient has a few, undisplaced rib fractures, it may be reasonable to undertake short procedures requiring positive pressure ventilation without placement of a chest tube. However, the anaesthetist must be alert to any signs of a pneumothorax and must ensure easy immediate access to the chest for needle decompression and chest tube placement. Computed tomography (CT) scanning of patients with serious injuries may reveal occult pneumothoraces, which are visible on the CT scan but not on a plain chest radiograph. There is no consensus on whether these should be drained routinely.
