**4. Video laryngoscopy use guidelines**

The 2022 American Society of Anesthesiologists Practice Guidelines for Management of the Difficult Airway defines a difficult laryngoscopy as "not possible to visualize any portion of the vocal cords after multiple attempts at laryngoscopy". Evidence cited in the guidelines support the use of video-assisted laryngoscopy in patients with predicted difficult airways. As stated in the guidelines, meta-analyses of randomized controlled trials comparing video-assisted laryngoscopy with direct laryngoscopy in these patients reported improved laryngeal views, higher frequency of successful intubations, higher frequency of first-attempt intubations, and fewer maneuvers with video-assisted laryngoscopy [4, 11–20]. Differences in time to intubation between the two techniques were equivocal [12, 14–16, 19–22]. When comparing video-assisted laryngoscopy with airway laryngoscopy using a flexible intubation scope, randomized controlled trials reported equivocal findings for laryngeal view, visualization time, first-attempt intubation success, and time to intubation [23–26]. In terms of which video laryngoscope is recommended, when comparing hyper-angulated video laryngoscopes with non-angulated video laryngoscopes for anticipated difficult airways, randomized controlled trials reported equivocal findings for laryngoscopic view, intubation success, first-attempt intubation success, and time to intubation [18, 20]. Additionally, comparisons of channel-guided with non-channel-guided video laryngoscopes found equivocal results for laryngeal view, intubation success, first-attempt intubation, time to intubation, and needed intubation maneuvers [17, 27]. VL is currently considered a first-line airway maneuver in airway management algorithms around the world and is being viewed as essential to standard of care in airway management.
