Difficult Airway Management in Neonates: Comment.

I read with interest the article by Thomas et al.1 on fiberoptic tracheal intubation via a laryngeal mask airway (LMA) Unique (Laryngeal Mask Company Limited, USA) in neonates. They state that, to perform this, it is necessary to use a second tracheal tube as a “pusher” (not a Food and Drug Administration–approved device), because “[a]n LMA Unique size 1 is only a few centimeters shorter than an uncuffed 2.5-mm ETT [tracheal tube], so advancing the ETT into the trachea through the LMA is impossible without assistance.” I point out that this is not accurate.As the authors state, when a 2.5-mm or 3-mm ID tracheal tube is passed through a size-1 LMA Unique or LMA Classic (the same specification as the LMA Unique), the tracheal tube projects 2 to 3 cm beyond the grille (at the distal end of the breathing tube) of the LMA. Therefore, when the distance between the grille of the LMA and the glottis is shorter than 2 to 3 cm, it should be possible to advance a tube beyond the glottis. In adults, the mean (and the range) of this distance is 3.6 (2.5 to 4.7) cm in men and 3.1 (2.0 to 4.2) cm in women.2 No studies have formally measured this distance in neonates, but this is usually less than 1 cm, and thus intubation should usually be possible. I have reported successful fiberoptic intubation through an LMA Classic in five neonates with difficult airways,3 and have continued to use this method since then, but I have not experienced any case in which a tracheal tube was too short to reach beyond the glottis.The use of a second tube as a “pusher” (or more appropriately, a “stabilizer”) has already been reported,2 and for adult patients, a “Stabilizer Rod” is commercially available. Dr. Thomas et al. described that a tracheal tube (with its connector detached) is inserted to the LMA, a fiberscope is advanced through the tube into the trachea, and the tube is “pushed” into the trachea by the second tracheal tube that has already been placed over the fiberscope. One major problem with this method is that it is impossible to ventilate the lungs, until both the fiberscope and the LMA have been removed, a connector is reattached to the intubated tube, and the breathing system is attached to the tube. In anesthetized neonates with difficult airways, apnea time taken for these procedures may not be short enough to prevent hypoxia. In addition, removal of the LMA is not an easy task, and thus doing these procedures in haste would increase the risk of inadvertent tracheal extubation, resulting in a “cannot intubate, cannot oxygen” situation. Furthermore, in an awake neonate,2 the removal of the LAM is stressful to the patient, and any movement of the neonate would further increase the risk of tube dislodgement. More appropriate methods would be as follows, with several merits:The author declares no competing interests.