Impact of pillow height on double-lumen endotracheal tube intubation with McGRATH MAC: a prospective randomized clinical trial

•The appropriate height for DLT intubation with McGRATH MAC has not been clarified.•We evaluated the DLT intubation efficacy using McG in high (HP) and low (LP) pillow.•Intubation profile for intubation time and intubation attempt number were measured.•Intubation time and number were significantly improved in the HP compared with the LP.•The HP showed a better intubation profile with McG due to smooth tracheal intubation.

Study objectiveThis study aimed to compare the impact of pillow height on double-lumen tracheal tube (DLT) intubation with McGRATH MAC (McG) in patients undergoing elective surgery.DesignRandomized clinical trial.SettingOperating room.PatientsFifty adult patients scheduled for elective surgery under 1-lung ventilation with an American Society of Anesthesiologists physical status of 1 to 3.InterventionsDLT intubation with McG was performed with a high pillow (HP group; 25 patients) or low pillow (LP group; 25 patients) by anesthesiologists.MeasurementsIntubation time, number of laryngoscopy, number of tracheal intubation attempts to successful intubation, percentage of glottic opening score, and subjective difficulty of laryngoscopy and tube passage through the glottis were assessed.Main ResultsIntubation time was significantly shorter in the HP group compared with the LP group (HP: 32.1 ± 14.9 seconds vs LP: 49.4 ± 11.2 seconds, P < .001). The number of laryngoscopy were 1 (HP group, 22 patients; LP group, 17 patients), 2 (HP group, 3 patient; LP group, 7 patients), and 3 (HP group, 0 patient; LP group, 1 patient), with no significant difference between the 2 groups (P = .197). Although the percentage of glottic opening score did not significantly differ between HP and LP groups (HP: 95.6% ± 6.7% vs LP: 96.0% ± 12.3%, P = .08), the number of tracheal intubation attempts was significantly lower in the HP group compared with the LP group (P = .009). The visual analog scale score for laryngoscopy did not significantly differ between the 2 groups (P = .54). However, the visual analog scale for tube passage through the glottis was significantly higher in the LP group than in the HP group (P < .001).ConclusionsIntubation with an HP was associated with a better DLT intubation profile than with an LP with McG, possibly due to smoother tracheal tube progression through the glottis.