Use of a lighted stylet for intubation via the laryngeal mask airway

To assess a new technique for intubation via the laryngeal mask airway (LMA) in which a lighted stylet is used to optimise the position of the LMA before intubation.

In 114 patients, following LMA insertion, the lighted stylet (Trachlight Wand) with mounted tracheal tube (TT) was advanced 1.5 cm beyond the mask aperture bars and the anterior neck observed for a distinct central point of light at the cricothyroid membrane (CTM). If this was not seen, the LMA was repositioned in the pharynx, depending on the location of the light, by manually advancing, withdrawing or rotating the device, manipulating the head/neck or trying an alternative size. Tracheal intubation was attempted only when transillumination was correct. The TT with lighted stylet was advanced until the supra-sternal notch was transilluminated.

In 89 patients (78%) the CTM was transilluminated without repositioning, in 12 (10%) a single positional adjustment was required, and in 10 (9%) a change of LMA size was required. In three patients (3%) transillumination of the CTM was impossible. In the 97% of patients in whom transillumination was correct, tracheal intubation was successful in all at the first attempt without the need for further repositioning or size change.

The lighted stylet is useful in facilitating intubation via the LMA in anaesthetised adult patients when used as a guide to optimal LMA position.