The use of paraglossal straight blade laryngoscopy in difficult tracheal intubation.

In 10 cases of unexpected difficult tracheal intubation using the Macintosh laryngoscope blade, the larynx could not be seen. In each case, a good view was achieved using the Miller blade lateral to the tongue, which enabled tracheal intubation under direct vision. The results achieved using narrow, low-profile straight laryngoscope blades with this technique are reviewed. The improved view obtained with this technique is a consequence of reduced tongue compression as compared with the Macintosh technique. This leads both to an improved line of sight, and to a reduced risk of backward displacement of the tongue and epiglottis. In addition, the molar or retromolar variation of the technique reduces the intrusion of maxillary structures into the line of sight, so that a better view of the larynx is achieved for a given degree of soft tissue compression. Paraglossal straight blade laryngoscopy may have an advantage over use of the Macintosh technique when intubation proves unexpectedly difficult. It is perhaps time to question standard teaching about the role of the curved blade in such patients or, more particularly, whether the technique of laryngoscopy as currently taught is optimal. The paraglossal straight blade technique needs to be practised in routine intubation before it can be used with confidence in difficult cases.