LAUSR

We would like to ask Angerman et al. some questions about their observational study of routine bougie use during videolaryngoscopy [1]. Firstly, do the authors think that their positive findings reflect the benefits of using a bougie with a C-MAC , or merely the inflexible implementation of a treatment algorithm? Secondly, do they think that they should have included cases where standard Macintosh laryngoscopes were used in the ‘before’ group? Thirdly, do they consider that a simple comparison of C-MAC bougie vs. stylet may have had broader significance? The authors’ desire to standardise bougie use with the videolaryngoscope is perhaps reflective of growing concern amongst anaesthetists that strategies for ‘getting the tube in’ are suboptimal. The work (quoted in their discussion) by Trimmel et al., describing common failure in advancing the tracheal tube (TT) despite being able to see the vocal cords easily, supports this concern [2]. Although we accept that many clinicians are very skilled at using stylets safely, we agree with elective bougie use in the context of videolaryngoscopy, and believe that stylets may end up following trochars into medical antiquity. However, bougies are by no means perfect, and can also cause trauma when used inappropriately. The Frova intubating introducer (Cook Medical, Bloomington, USA) used in the study, for example, has been shown to transmit much greater forces in manikin studies than traditional, reusable gum elastic bougies [3]. Masters and Rope have highlighted the usefulness of a curved Yankauer suction catheter as a conduit for a smaller bougie, to facilitate ‘getting around the corner’ created by the C-MAC [4]. They claimed this also facilitated the ‘railroading’ of smaller tracheal tubes, such as micro-laryngoscopy/laser tubes, as a thinner 10-Fr bougie could be used regardless of whether it retained its bend, even if this technique requires an assistant to advance/retract the bougie at the request of the intubator, whose other hand is gripping the handle of the C-MAC. We have been working on an ergonomic solution, which enables the intubator to use their free hand to deploy a 10-Fr bougie around the corner created by the C-MAC Dblade – itself more curved than the Macintosh blades. The principle is akin to that of the Seldinger technique – where in place of a wire, there is a 10 Fr-bougie. The bougie introducer (OS introducer, AgorIP, Swansea University, Fig. 1a) enables accurate advancement of the softer bougie in a straight line into the glottis, without catching on the tracheal rings. Small rotational movements at the wrist enable the tip of the OS introducer to hover precisely over the glottis (Fig. 1b), and the bougie can then be advanced by the operator’s thumb into the trachea (Fig. 1c), without causing abrasions or trauma to the mucosa (Fig. 1d). Although this turns intubation into a three-stage process, we feel the security of ‘knowing you are in’ is of greater importance than a cumbersome, and potentially traumatic one or two-stage technique.