In Response.

Abstract

November 1, 2017 • Volume 9 • Number 9 www.anesthesia-analgesia.org 275 In Response We thank Professor Grocott 1 for his interest and insightful comments regarding our case report. We agree that there is more than 1 way to secure a definitive airway in the case that we described, and in our report, we briefly discussed alternative techniques that we could have used including a wire through a fiberoptic bronchoscope (FOB) guided tube exchange.2 The previously described3,4 method, to which you refer, as used successfully by Hollingsworth et al5 uses an intraluminal FOB Aintree intubation catheter (AIC; Cook Medical Inc, Bloomington, IN) technique for exchanging the King Laryngeal Tube (LT; King Systems, Noblesville, IN) for an endotracheal tube (ETT). This does have the advantage, as you rightly pointed out, of reducing “step off” and hang up of the ETT when railroaded through the larynx in a Seldinger technique. Moreover, it also allows continued oxygen insufflation or limited lung ventilation via its hollow lumen (inner diameter 4.7 mm) and supplied Luer Lock or 15 mm connectors should endotracheal intubation not succeed. However, we would suggest that the intraluminal FOB AIC technique to which you refer would have been less than ideal in our situation and is why, although it is an accepted and welldescribed technique, we failed to reference it. In our discussion, we did elucidate several patient factors, peculiar to our case, that led us to choose a videolaryngoscope-guided extraluminal FOB approach to exchange the LT for an ETT. As the AIC has an outer diameter (OD) of 6.0 mm, the smallest ETT recommended by the manufacturer is 1 with an OD of 7.0 mm. Given that our patient had a large goiter displacing and compressing her trachea and had also had multiple attempts at direct laryngoscopy by prehospital paramedic staff, we were concerned that her laryngeal opening and tracheal airway might be significantly narrowed. This led us to use the extraluminal approach described, which allowed a narrower 6.5 mm ETT to be passed over the FOB. We also used an FOB with OD of 5.2 mm (Karl Storz, Tuttlingen, Germany); the recommended scope diameter for placing the AIC (inner diameter 4.8 mm) is 4 mm. The increased rigidity of a wider bronchoscope likely facilitated passage past the cuff of the LT, and the wider OD of the FOB reduced “step off” when railroading the ETT. Our technique did minimize interruption of minute ventilation allowing tight control of the Paco2, thus reducing further rises in intracranial pressure and avoiding respiratory acidosis given our patient’s expanding intracerebral hematoma and history of myotonic dystrophy. The FOB AIC technique also allows continued ventilation albeit through a reduced lumen due to the position of the FOB within the lumen of the LT. This might have made control of Paco2 more challenging. Regarding airway management, knowledge, preparation, and practice are critical, along with the need to avoid fixation error in relying only on the 1 technique, as not every method will be appropriate for all situations. Therefore, we would suggest that, in the management of such cases, while the anesthesiologist “jockey” needs to be a master of multiple techniques, they should initially choose the best “horse” in terms of approach for the “course” or situation they face. We would also emphasize that preparation for a surgical airway, at least as a backup plan, must always be considered.6