GlideScope versus C-MAC D-blade videolaryngoscope for double-lumen tube intubation in patients with anticipated difficult airways: A multi-center, prospective, randomized, controlled trial

Study objective: Videolaryngoscopes are widely used to visualize difficult airways. Our aim was to compare the GlideScope and C-MAC D-blade videolaryngoscopes for double-lumen tube (DLT) intubation in patients with difficult airways.Design: A multi-center, prospective, randomized controlled trial. Setting: Three comprehensive tertiary, high-volume hospitals from 5 December 2020 to 4 November 2021.Patients: We included 348 adult patients with anticipated difficult airways who underwent elective thoracic surgery.Interventions: Patients were randomized into two groups: GlideScope and C-MAC D-blade. Following anesthesia induction, DLT intubation was performed using different videolaryngoscopes. Measurements: The primary outcome was the first-pass success rate of DLT intubation. All other results were recorded as secondary outcomes.Main results: No significant differences were observed in the first-pass success rate of DLT intubation between the GlideScope and C-MAC D-blade (86.21% and 89.66%, respectively; P = 0.323). However, compared with the GlideScope, the C-MAC D-blade provided a lower Cormack-Lehane grade (P < 0.001), lower rates of external laryngeal pressure (48 vs. 15, P < 0.001), and postprocedure sore throat (26 vs. 8, P < 0.001). The numerical rating score for difficulty of videolaryngoscope insertion into the oral cavity, delivery to the glottis, and intubation into the main bronchus were significantly lower when using the C-MAC D-blade (P < 0.001). Moreover, the duration of DLT intubation was shorter in the C-MAC D-blade group (81 s [70-97 s] vs. 95 s [78-115 s], P < 0.001). In each group, two patients underwent fiberoptic intubation after three attempts with a video-laryngoscope failed.Conclusions: In patients with difficult airways, the GlideScope and C-MAC D-blade provided a similar success rate on the first DLT intubation attempt; however, the C-MAC D-blade offers a better glottic view, easier and faster intubation, and lower incidence of sore throat.