Assessment of laryngeal view: Percentage of glottic opening score vs Cormack and Lehane grading

Purpose: To examine the intra- and inter-rater reliability of two methods t hat categorize laryngeal view during direct laryngoscopy, the Cormack-Lehan e grading system and a new scale, the percentage of glottic opening (POGO) scale. Methods: Seven anesthesiologists from the University of Pennsylvania Health System viewed 25 identical pain of slides of laryngeal views during direct laryngoscopy. Each anesthesiologist rated the 50 slides for both Cormack-L ehane grades and POGO scores. The latter CL replaces grades 1 and 2 C-L gra des with a percentage of glottic opening: the POGO score. Inter and intra-p hysician reliability for the Cormack-Lehane grades were determined using th e kappa statistic analysis, comparison of POGO scores was performed using t he intraclass correlation coefficients (r(1)). Results: The POGO score had a better inter and intra-physician reliability than the Cormack-Lehane grading system. The intra-physician reliability for the POGO score was very good with an average interclass r(1) value of 0.88 . The inter-physician score was good with a r(1) of 0.73. The Cormack-Lehan e grading system had excellent intra-physician concordance (average kappa = 0.83.) but the inter-physician reliability was poor (kappa = 0.16.) Conclusion: The Cormack-Lehane grading system has very poor inter-physician reliability The lack of inter-physician reliability with Cormack-Lehane gr ading calls into question the results of previous studies in which differen t laryngoscopists used this method to assess laryngeal view. The POGO score appears to have good intra and inter-rater reliability. It has several the oretical advantages and may prove to be more useful for research studies in direct laryngoscopy.