Alternative techniques for tracheal intubation

Alternative rigid blade intubation devices have become available in recent years: retro-molar straight blades, Glidescope, Airtraq and Bonfils laryngoscopes. Conventional rigid curved blades work by displacing the tongue to one side and also into the submandibular space. Under less favourable intubating conditions, the tongue tends to be compressed and the blade tip cannot be drawn forward (hence the incorrect description of an ‘anterior larynx’ because it is usually the blade that is posterior). Retro-molar instruments try to avoid this problem by starting from a lower position in the mouth and approaching the larynx alongside the tongue. The potential to do this is dependent on the local dental and maxilla/mandibular alignment. Under ideal conditions, the Airtraq sits on the posterior pharyngeal wall and the view is maintained without additional effort. With moderate head flexion and the bulk of the instrument, tongue compression becomes feasible. The Bonfils acts as a rigid stylet inside a small tracheal tube (6.0 mm internal diameter) and is used from a retro-molar position; thus, it requires the minimum of tongue displacement. Tongue compression with the Macintosh blade is addressed in different ways and to different degrees by the new devices. Improved viewing conditions have not necessarily resulted in easier intubation conditions, shorter intubation times or improved success rates. As with the Macintosh blade, they all have the disadvantage of requiring general anaesthesia for normal use. Some also have learning curves to maximize their potential. Unfortunately, new complications appear to be associated with at least some of them.