Title: Use of a tracheal tube and capnograph for insertion of a feeding tube
Abstract: A feeding tube can be inadvertently inserted into the tracheobronchial tree and may even penetrate the pleura, causing pneumothorax [1, 2]. In demented or unconscious patients, insertion of the tube into the trachea sometimes does not induce protective airway reflexes and thus the incident may not be detected [1, 2]. Infusion of nutrients through the tube in such a circumstance may be lethal [3]. Therefore, it is crucial to detect inadvertent insertion of a feeding tube in the airway. Previously, I suggested that the use of a capnograph would be one reliable method for detection [4]: after insertion of a feeding tube, a capnograph is connected to the proximal orifice of the feeding tube; if carbon dioxide is detected, the tube is likely to be in the airway. It is possible to minimise the incidence of migration of the tube into the intrapleural space if the absence of carbon dioxide output is confirmed at the point when the feeding tube has been inserted to a depth of 25 cm. However, this method requires removal of the guide wire from the feeding tube for the measurement of carbon dioxide and re-insertion of the wire for final positioning of the tube into the gastrointestinal tract. This re-insertion of the guide wire may damage the tube or may result in the wire protruding from a side hole of the feeding tube [5]. I now suggest that the use of a tracheal tube will solve this problem. A tracheal tube is inserted into the oesophagus and a sampling catheter of a capnograph is connected to the tracheal tube. When the tube is correctly inserted into the oesophagus, there should be no increase in carbon dioxide concentration. After this confirmation, a feeding tube is passed through the tracheal tube into the oesophagus and advanced into the gastrointestinal tract. The tracheal tube is then removed. Finally, the guide wire is removed, a capnograph is connected to the feeding tube and the absence of carbon dioxide emission is confirmed.