Objective. The competency of using video laryngoscopes (VL) for double-lumen tube (DLT) endobronchial intubations can be improved with constant training as assessed by measuring the learning curves. We hypothesized that the time to DLT intubation would be reduced over the intubation attempts. Design. A crossover manikin study. Settings. University-affiliated hospital. Participants. Forty-two novice medical students unfamiliar with DLT intubation. Interventions. Participants were randomly allocated to two sequences, including DLT intubation, using King Vision and McGrath VLs. Each participant completed 100 DLT intubation attempts on both simulated easy and difficult airways on two different mannikins using the study devices (25 attempts for each). Measurements and Main Results. The primary outcome was the time to DLT intubation. The secondary outcomes included the best glottic view, optimizing maneuvers, and intubation first-pass success. The use of King Vision VL was associated with a significantly shorter time to DLT intubation (P < 0.044 and P < 0.05, respectively) and a higher percentage of glottic opening (POGO) compared to the McGrath VL (P < 0.011 and P < 0.002, respectively) in the simulated "easy" and "difficult" over most of the intubation attempts. In the simulated "easy" airway, the first-pass success ratio was higher when using the King Vision VL (median [Minimum-Maximum] 100% [100%-100%] and 100% [88%-100%], P = 0.012). Conclusion. Novice medical students developed skills over intubation attempts, meaning achievement of a faster DLT intubation, better laryngeal exposure, and higher success rate on simulated "easy" and "difficult" airways. A median of 9 DLT intubations was required to achieve a 92% or greater DLT intubation success rate.
Keywords: Mcgrath®; double-lumen tube; king vision®; learning curve; video laryngoscope.