RECENTLY, transillumination of the soft tissue of the neck by lighted stylets (lightwands) has been reported to be useful for airway management. The overall success rates of lightwand intubation are between 97.9 and 100%. 1–5 However, the success rate on the first attempt has been variable, between 72 and 92.3%. 1–5 The manufacturer of the Trachlight (Laerdal, Armonk, New York) recommends that the device be bent at 6.5–8.5 cm (with a “bent here” maker on the shaft). It has been suggested that the bent length of a lightwand should be according to the estimated distance between the back of the pharynx and the vocal cords. 6,7 However, there were no suggestions on how this distance should be measured, and there were no previous studies about the influence of the bent length on lightwand intubation.
In our daily practice, we found that the bent length of a lightwand should be approximated to the individual's thyroid prominence–to–mandibular angle distance (TMD) for a smooth lightwand intubation. The purposes of this study were to obtain knowledge of the distribution of the TMD in adult patients and to test the applicability of the suggested bent length in patients with different TMDs.
