Evaluation of the Accuracy and Reliability of the Percentage of Glottic Opening Score

Overview

Current classifications of the laryngeal view during laryngoscopy are criticized for being subjective. The modified CL classification is criticized as it does not predict difficult intubation and especially grade 2 is operator dependent and partial view is not well defined. The numerical expression of the percentage of the glottic aperture (POGO = percentile of glottic opening) is another score. In this score, A POGO score of 100% accounts for full visualization of the larynx starting from anterior commissure to the posterior cartilage, while 0% indicated a complete absence of glottic opening. Previous validation studies reported on the reliability of POGO; however, accuracy was not evaluated. The use of a standard and effective classification method will facilitate and accelerate communication between anesthetists in difficult life-threatening situations such as difficult airway / difficult intubation / difficult ventilation and contribute to patient safety. The use of common terminology can also facilitate the evaluation of the performance of intubation tools. The aim of this study was to evaluate the accuracy and intra and inter rater reliability of the POGO score

Reviewer anesthesiologist will be asked to score still images of laryngeal views, which will be obtained from patients requiring intubation for general anesthesia, after obtaining written informed consent. The images of the larynx will be captured first with the Macintosh blade and thereafter with the D blade. An expert panel will score these images with the Cormack Lehane and POGO scores. The set of images will be prepared from patients with both difficult and normal airway anatomy. Some images in the series will be repeated to assess intra rater variability. The anesthesiologist will be asked to rate 20 images both with the CL and POGO scores. The experience of the raters in airway management, their experience with videolaryngoscopy and scoring systems used currently when documenting videolaryngoscopy and demographic data will be also obtained. The POGO scores of the participants and investigators will be compared. The primary outcome measure was the reviewer's agreement with the correct POGO scores (accuracy).