Brian E. Driver MD, Matthew E. Prekker MD, Richard M. Levitan MD, Jeffrey Corajod MD, Erin Karl MD, Andrew D. Smith BS and Robert F. Reardon MD
Annals of Emergency Medicine, Copyright © 2021 American College of Emergency Physicians
When using a standard geometry laryngoscope, experts recommend engaging the hyoepiglottic ligament—a ligament deep to the vallecula not visible to the intubator. The median glossoepiglottic fold (hereafter termed midline vallecular fold) is a superficial mucosal structure, visible to the intubator, that lies in the midline of the vallecula. We aimed to determine whether engaging the midline vallecular fold with a standard geometry blade tip during orotracheal intubation improved laryngeal visualization.
We reviewed laryngoscopic videos from intubations by emergency physicians using standard geometry video laryngoscopes over a 2-year period. Two reviewers watched each video and recorded whether the blade tip engaged the midline vallecular fold (obscured the fold with the blade tip) and the best modified Cormack-Lehane grade and percent of glottic opening obtained. We compared laryngeal views in the presence and absence of fold engagement.
We analyzed 183 discrete laryngoscopic episodes, including 113 instances in which the midline vallecular fold was engaged and 70 instances in which the fold was not engaged. The proportion with a Cormack-Lehane grade 1 or 2a was higher with fold engagement (96%) than without (87%) (absolute difference 9% [95% confidence interval (CI) 1 to 18%]). Ordinal logistic regression demonstrated that midline vallecular fold engagement was associated with a more favorable Cormack-Lehane grade (odds ratio 2.1 [95% CI 1.1 to 4.2]). The median percent of glottic opening score was 95% (interquartile range 90 to 100%) with fold engagement and 95% (65 to 100%) without engagement (median difference 0% [95% CI 0 to 5%]).
Engaging the midline vallecular fold with the laryngoscope blade tip during orotracheal intubation when using a standard geometry blade was associated with improved laryngeal visualization.