Randomized controlled trial of the A.P. Advance, McGrath, and Macintosh laryngoscopes in normal and difficult intubation scenarios: a manikin study.

BACKGROUND Several videolaryngoscopes are available which may facilitate tracheal intubation in difficult airways. We compared the McGrath(®) Series 5 and the Venner™ A.P. Advance™ (APA) videolaryngoscopes with a Macintosh laryngoscope by studying the performance of experienced anaesthetists using manikins in normal and difficult airway scenarios. METHODS We recruited 48 anaesthetists into a randomized trial. Each performed tracheal intubation with each laryngoscope in one easy and one difficult laryngoscopy scenario. The primary endpoint was time to intubation. Other endpoints were time to best glottic visualization, grade of view, and number of glottic advances. RESULTS There were no dropouts. In the easy scenario, the time to intubation was greater using the McGrath [median time 40.7 s, inter-quartile range (IQR) 31.0, 57.4, P<0.001] than the other devices. In the difficult scenario, the time to intubation using the APA with Difficult Airway Blade (DAB) was less (median time 23.2 s, IQR 19.8, 29.0, P<0.001) than the other devices. Time to glottic visualization was reduced using the McGrath and the APA with DAB. Glottic advances were fewer using the APA with DAB. CONCLUSIONS Experienced anaesthetists required a longer time for intubation in a standard manikin using a McGrath compared with other laryngoscopes, but a shorter time for intubation in a difficult manikin using an APA with DAB, and with fewer glottic advances, compared with other laryngoscopes.