To the Editor:

In a recent study of Ching et al. [1] assessing the effect of incorporating lingual traction on success rate of fiberoptic orotracheal intubation(FOI), many known predictors of difficult airways were used to identify patients enrolled into the two groups. Besides the modified Mallampati score, however, other predictors were not reported and compared. The size of used fiberoptic bronchoscope (FOB) and orientation of tube on the FOB were also not mentioned. Actually, a close match between the external diameter of the FOB and the internal diameter of the tube is an important determinant of successful FOI. Furthermore, first-attempt success rate of FOI with the bevel facing posteriorly is significantly higher than that with the bevel facing left. The external laryngeal manipulation, jaw thrust, and adjusting the patient’s head and neck position were permitted at the discretion of operator, but the authors did not show whether uses of these maneuvers were comparable between groups. Did an imbalance in the above uncontrolled factors confound their results?

When used alone, lingual traction fails to produce full airway clearance for FOI in a significant number of patients [2]. According to their study design, the lingual traction group really used two maneuvers to aid FOI: Williams airway and lingual traction. Thus, it would be more appropriate to conclude that combined Williams airway and lingual traction can provide a higher success rate of first-attempt FOI than the use of Williams airway alone in anesthetized patients with anticipated difficult airways.