Use of a Lighted Stylet and the Laryngeal Mask for Tracheal Intubation

In Response: I thank Dr. Asai for his comments to my report [1]. Successful blind tracheal intubation through a laryngeal mask airway (LMA) without the use of an airway adjunct has been reported for a few years with variable results [2-5]. Light-guided tracheal intubation through the LMA using a lighted stylet can only improve the success rate because it allows the determination of the tip of the endotracheal tube during intubation. Although I reported an 80% success rate with this technique, transillumination helped to detect esophageal intubation and thus minimize complications in the remaining patients. The low success rate of this light-guided technique in my report (80%) and Asai et al.'s report (two of six patients) [6] may be a reflection of the design of the LMA, which is intended for ventilation and not for tracheal intubation. A newly developed intubating LMA (Fastrach; Vitaid, Toronto, ON, Canada) designed specifically for both ventilation and tracheal intubation is now available in Canada. I have tested this new device together with the Trachlight. The results of this ongoing study show a substantial improvement in the success rate of orotracheal intubation using the Fastrach. Tracheal intubation was successful in 26 of 27 patients after one attempt. The insertion and ventilation of the remaining patient was difficult with the Fastrach, and no tracheal intubation was performed through the Fastrach. Laryngoscopic tracheal intubation was easily performed with this patient. Although there are many effective and safe intubating techniques, each technique has its limitations. I agree with Dr. Asai that light-guided intubation through a LMA certainly has its limitations. However, I believe that light-guided intubation through the LMA is a significant improvement over the blind technique through the LMA. Light-guided intubation through the new intubating LMA (Fastrach) seems to have significant advantages over the LMA because its design permits the use of larger endotracheal tubes. Future evaluation of this technique with a large patient population is necessary to ensure its effectiveness and safety. Orlando R. Hung, MD, FRCPC Department of Anaesthesia, Dalhousie University; Queen Elizabeth II Health Sciences Centre; Halifax, Nova Scotia, Canada B3H 2Y9