Two-handed jaw thrust in patients undergoing intubation with a double-lumen endobronchial tube

Editor, We read with great interest the article written by Park et al.,1 which evaluated the effect of two-handed jaw thrust on postoperative sore throat in patients undergoing double-lumen endobronchial tube intubation. The authors stated that the jaw thrust manoeuvre could decrease resistance and physical damage to the vocal cords when the double-lumen endobronchial tube was passed through the glottic opening, resulting in decreased vocal cord lesions and reduced the incidence of postoperative sore throat. We highly appreciate their efforts on their innovative study. However, we note two issues in this study that were not clearly addressed, which may affect the validity of the conclusions. First, to our knowledge, the lubrication of tracheal tube is helpful to decrease resistance and attenuate airway injuries,2 and topical lubricants (such as lidocaine gel, benzydamine hydrochloride gel etc.) have been shown to be effective in preventing postoperative sore throat.3 However, whether topical lubricants were used when performing double-lumen endobronchial tube intubation and whether the types of local lubricants were the same in both groups are not clearly described in this article. In other words, whether the two-handed jaw thrust manoeuvre could reduce the incidence of postoperative sore throat in patients undergoing insertion of a double-lumen endobronchial tube remains controversial. Furthermore, it is more difficult to deliver the double-lumen endobronchial tube to the laryngeal inlet because of its wider external diameter, less compliant characteristics and straighter shape. Therefore, the technique of modifying tube shape according to each patient's upper airway axes is often used for intubation with a double-lumen endobronchial tube to facilitate double-lumen endobronchial tube delivery to the glottis and reduce intubation complications.4 However, whether the technique of modifying the shape of the tube was used in both groups was not clearly described. Thus, we are curious about whether the reduction of postoperative sore throat was due to the jaw thrust manoeuvre or the technique of modifying the shape of the tube. We believe that this would help to convince readers by clarifying the above issues.