Novel technique for uninterrupted confirmation of endotracheal tube position for awake fiberoptic intubation

Abstract

Misplacement of an endotracheal tube in a patient with a difficult airway is catastrophic. Currently used techniques do not permit simultaneous bronchoscopic and capnographic confirmation of tube placement. We report a novel technique for seamless monitoring of the endotracheal tube position in the tracheobronchial tree during Awake Fibre Optic Intubation (AFOI). The simple modification described improves the safety profile of AFOI in several ways. The modification allows an overlap between the bronchoscopic viewing of the endotracheal tube in the trachea and the appearance of the typical wave on the capnograph. It only requires an endotracheal tube connected to a catheter mount. The bronchoscope is then introduced via the port on the catheter mount. The tube-catheter mount unit is secured to the scope (Figure 1). A ventilator circuit with attached capnograph adapter is connected to the catheter mount once the endotracheal tube is advanced into the trachea. Ventilation is then initiated. Appearance of the characteristic wave on capnograph confirms the correct position before the extraction of the bronchoscope Migration of the tube into the oesophagus is unnoticed until the bronchoscope is completely removed from the trachea in 5±10% of AFOIs1,2. Displacement of endotracheal tube into the oesophagus despite the bronchoscope tip being positioned in the trachea has been described3. Resistance that is felt as the tube is advanced over the mid part of the scope looped into the oesophagus may be misinterpreted as the tube tip impinging on the arytenoid cartilages3. The tube slides into the oesophagusas the scope is extracted. This usually occurs before capnographic confirmation is possible3. The technique we propose will be useful since ventilation is initiated with the scope in-situ. Loss of the capnographic trace is evidence of misplacement of the tube, though the bronchoscope is within the trachea. We propose this should be the standard of care and should be included in the AFOI training protocols.