Use of the GlideScope®for double-lumen endobronchial intubation

Abstract

Dr Russell et al. recently published the results of a randomised controlled trial comparing the GlideScope® with the Macintosh laryngoscope for double-lumen endobronchial intubation 1. We would like to thank our colleagues from Toronto for performing this study, which provides useful information on the use of GlideScope for this purpose, but wish to comment on some aspects of this study compared with a preliminary observational study published in 2012 2. Firstly, the operators were similar in both centres with regard to training with the GlideScope and also with the concomitant use of the GlideScope with double-lumen endobronchial intubation. The ratio of operators to cases was comparable, with 30 operators/80 cases (38%) in Toronto and 17/50 (34%) at our institution. Secondly, the authors reported a 17% failure for first attempt at intubation with the GlideScope, compared with 9% with the Macintosh, stating that these results are similar to those in our study. We indeed reported a failure rate of 26% on the first attempt with the GlideScope in our study, but the time allowed to succeed was 60 s, as opposed to 120 s in Toronto. In Quebec City, our failure rate was 4% at 120 s (unpublished data). Thirdly, Russell et al. reported that three out of 40 cases had cuff rupture with the GlideScope, but none in the Macintosh group. Unfortunately, they did not mention how many subjects had upper teeth. In our study, we had 17/50 (34%) subjects with upper teeth and we had no tracheal cuff ruptures. This occurs frequently in the presence of upper teeth when using a double-lumen endobronchial tube. We described in 1999 a technique to help minimise this problem, simply by inserting the tube in the mouth before the laryngoscope, and we use it successfully with the GlideScope as well 3. Fourthly, the main difference between these two studies is that we used the GlideRite Double-Lumen Tube Stylet (GR-DLT-S) we designed in 2009, in collaboration with Verathon Medical Inc. (Bothell, Washington, USA). This semi-rigid stylet is a safe and effective way to ease the insertion of the double-lumen endobronchial tube with minimal trauma. In Toronto, the original malleable stylet supplied with the double-lumen endobronchial tube was used. The operator shaped it to replicate the curve of the GlideScope or the Macintosh blade's curvature as needed. In our experience, this original aluminium stylet is too malleable and does not maintain its curvature when facing any obstruction in the upper airway. We postulate that the difference in the rate of success at 120 s (96% in our study vs 83% in the Toronto study) might be explained by the use of different stylets, knowing that operators had similar expertise with the GlideScope. We agree with the authors that the GlideScope is not an easy device to use for double-lumen endobronchial intubation, particularly with novices. Our conclusion is that using GlideScope in combination with a double-lumen endobronchial tube requires training. The presence of upper teeth and small mouth opening might add some degree of difficulty but the use of special techniques and facilitating tools, such as the GR-DLT-S, can greatly improve the success rate of intubation. In our teaching institution, we encourage the use of the GlideScope/DLT/GR-DLT-S combination for every case in order to develop our expertise with these devices and to enable us to be more efficient when facing a difficult intubation.