Design: Prospective multicentre observational study, 44 hospitals
Population: 5,302 videolaryngoscopic tracheal intubations with paired assessments
Primary outcome: Relationship between glottic view (POGO) and tube delivery; inter-rater reliability
Effect: Difficult or failed in 6.3% with POGO above 75%; easy in 24.5% with POGO below 25%; alpha 0.86

This prospective study across 44 hospitals assessed 5,302 videolaryngoscopic intubations twice, by the operator and an independent observer, using a three-part description: blade type, glottic view by percentage of glottic opening (POGO), and how tube delivery went.

The two raters agreed closely, so the framework is reproducible. But view and ease came apart. With an excellent view, more than 75% of the glottis visible, the first approach was still difficult or failed in about one in 16 cases. With any view of at least 25%, about one in ten intubations was difficult or failed. And about a quarter of intubations with a poor view were rated easy.

With hyperangulated blades in particular, seeing the cords and getting the tube to them are separate problems. A record that says only 'grade 1 view' tells the next anaesthetist very little about what they will face.

This is observational and the difficulty ratings are partly subjective. The practical lesson is about documentation: record what was used, what was seen and what was done, so an airway alert carries useful information.

Document blade type, glottic view and ease of tube delivery after every videolaryngoscopic intubation.
Do not record a videolaryngoscopic intubation as easy on the basis of the view alone.
Have a stylet or bougie ready when using a hyperangulated blade, even with a good view.
Record adjuncts and number of attempts in airway alerts.
Teach trainees that tube delivery is a separate skill from obtaining the view.

Why it matters

Airway records that report only the view mislead the next team about how hard the tube will be to pass.

The statistics, in plain English

A Krippendorff's alpha of 0.86 means the two raters agreed closely, well above chance. The 6.3% figure means about 1 in 16 intubations with an excellent view were still difficult or failed on the first approach.