Association between glottic view and tracheal intubation during videolaryngoscopy: a prospective observational study

INTRODUCTION: A good view of the glottis with videolaryngoscopy does not translate consistently into straightforward tracheal tube delivery, suggesting a dissociation between visualisation and procedural execution. When videolaryngoscopy documentation is based on laryngeal view alone, it does not reliably reflect the performance of tracheal intubation. We evaluated this relationship and the reproducibility of a structured classification framework for videolaryngoscopic tracheal intubation. METHODS: We conducted a prospective multicentre observational study across 44 hospitals. Videolaryngoscopic tracheal intubations were assessed independently by an airway operator and an observer using a three-domain classification: blade geometry; glottic view using the percentage of glottic opening (POGO) score; and tracheal tube delivery. Inter-rater reliability was assessed. The relationship between glottic view and tracheal tube delivery was analysed across predefined POGO categories. RESULTS: A total of 5302 tracheal intubations with paired assessments were analysed. The overall inter-rater agreement for the three-domain classification was high (Krippendorff's α = 0.86, 95%CI 0.85-0.87). Among tracheal intubations with poor view (POGO < 25%), 37/151 (24.5%) were classified as easy. Among tracheal intubations with POGO ≥ 25%, 527/5151 (10.2%) were classified as difficult or failed. Even with excellent glottic view (POGO > 75%), the initial strategy was classified as difficult or failed in 252/4025 (6.3%) of cases. DISCUSSION: The ease of tracheal intubation with videolaryngoscopy cannot be inferred from glottic view alone. A structured approach that incorporates what was used, what was seen and what was done may improve communication in clinical practice.