A useful device for difficult nasal tracheal intubation in China

Abstract

Editor, There are a wide variety of options for anticipated difficult intubation, and the fibreoptic bronchoscopes and intubation laryngeal mask airway have been advocated as effective tools for difficult intubation [1,2]. At times, when none of the instruments is available, alternatives need to be considered. The blind intubation device (BID), manufactured by Anhui Xiaoshan Hygienic Material Co Ltd, Jixi County, China, is a new single-use intubation device and seems to be one such alternative in our institute. The BID (Fig. 1) consists of a battery cell, a light-guided catheter and an oesophageal tube. The light-guided catheter is a 70 cm long flexible wire, with an external diameter of 3.5 mm and a fixed anterior curvature of 30° at the tip. At the anterior tip, there is also a small light bulb. The oesophageal tube is a graduated, single-lumen polyvinyl chloride (PVC) tube, with an inner diameter of 6.0 mm and a round dead end. At a distance of 6 cm from the dead end, there is an ellipse gap with a 30° ramp at its bottom. Over the ellipse gap is a cuff which can be inflated. The intubation technique (Fig. 2) is easy. The patient is prepared with nasal decongestants. Routine monitoring is applied. After intravenous administration of a sedative dosage of fentanyl and midazolam, the procedure of adequate topical anaesthesia of the nares and nasopharynx is performed with 7% lidocaine spray. After preparing the oesophageal tube with lubricant, blind nasal oesophageal intubation is performed in the ‘sniff position’. The patient is asked to swallow when resistance to advancement is felt. After being inserted into the oesophagus, the oesophageal tube is withdrawn slowly until the tubular sound is heard clearly by the anaesthesiologist, which means that the ellipse gap is pointed exactly towards the glottis. Thereafter, the light-guided catheter is inserted into the oesophageal tube. The oesophageal tube can be adjusted slowly by the anaesthesiologist according to the location of the light spot until a bright light spot passes through the front of the neck, which means the light-guided catheter has entered into the glottis. Thereafter, the oesophageal tube is withdrawn carefully. Once the oesophageal tube has been removed, the endotracheal tube is guided and inserted into the trachea over the light-guided catheter. The correct position is confirmed with auscultation and with confirmation of end-tidal capnography.Fig. 1Fig. 2The BID is a battery-operated disposable device and appears to be safe and reliable for difficult nasal tracheal intubation. It is useful in patients with limited mouth opening and even in patients with no mouth opening. It is also helpful in patients who have limited or no neck mobility. The PVC oesophageal tube can be easily used in nasal oesophageal intubation. Below the gap, the 30° ramp makes the tip of the light-guided catheter slide into the glottis easily. Additionally, the oesophageal tube allows for oxygenation and ventilation before tracheal intubation is attempted, and the oesophageal tube can be used as the sole airway without tracheal intubation when its cuff is being inflated. The major limitation of the BID is failure to view the light spot in some burns patients with severe scarring in the neck. Second, the inner diameter of the oesophageal tube is 6.0 mm so the size of the endotracheal tube should not be less than 6.0 mm. However, further studies are required to compare the BID with other difficult intubation devices.