Abstract
Purpose
To examine the intra- and inter-rater reliability of two methods that categorize laryngeal view during direct laryngoscopy, the Cormack-Lehane 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 pairs of slides of laryngeal views during direct laryngoscopy. Each anesthesiologist rated the 50 slides for both Cormack-Lehane grades and POGO scores. The latter CL replaces grades 1 and 2 C-L grades with a percentage of glottic opening: the POGO score. Inter and intra-physician reliability for the Cormack-Lehane grades were determined using the kappa statistic analysis, comparison of POGO scores was performed using the intraclass correlation coefficients (r1).
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 r1 value of 0,88. The inter-physician score was good with a r1 of 0.73. The Cormack-Lehane grading system had excellent intraphysician 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 interphysician reliability with Cormack-Lehane grading calls into question the results of previous studies in which different laryngoscopists used this method to assess laryngeal view. The POGO score appears to have good intra and inter-rater reliability. It has several theoretical advantages and may prove to be more useful for research studies in direct laryngoscopy.
Résumé
Objectif
Vérifier la fiabilité intra et interobservateur de deux méthodes de classification de la vue du larynx pendant la laryngoscopie directe: le système de cotation de Cormack-Lehane et une nouvelle échelle, le pourcentage d’ouverture glottique (POG).
Méthode
Sept anesthésiologistes de l’University of Pennsylvania Health System ont visionné 25 paires identiques de diapositives du larynx sous laryngoscopie directe. Chaque anesthésiologiste a coté les 50 diapositives selon les échelons Cormack-Lehane et les scores POG. Cette dernière échelle remplace les rangs 1 et 2 C-L par un pourcentage d’ouverture glottique: le score POG. La fiabilité inter et intraobservateur des rangs Cormack-Lehane a été déterminée par une analyse statistique kappa, la comparaison des scores POG a été réalisée en utilisant des coefficients de corrélation interclasses (r1).
Résultats
Le POG a fourni une meilleure fiabilité inter et intraobservateur que le système de cotation Cormack-Lehane. La fiabilité intraobservateur du score POG a été très bonne, la valeur interclasse moyenne r1 étant de 0,88. Le score interobservateur a été bon selon un r1 de 0,73. Le système de Cormack-Lehane a donné une excellente concordance intraobservateur (kappa moyen = 0,83) mais la fiabilité interobservateur a été pauvre (kappa = 0,16).
Conclusion
Le système de cotation Cormack-Lehane a présenté une très pauvre fiabilité interobservateur. Cette lacune remet en question les résultats d’études antérieures où différents médecins ont utilisé la méthode pour évaluer la vue du larynx. Le score POG semble avoir une bonne fiabilité intra et interévaluateur. Il présente certains avantages théoriques et peut se révéler plus utile lors de recherches en laryngoscopie directe.
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Ochroch, E.A., Hollander, J.E., Kush, S. et al. Assessment of laryngeal view: Percentage of glottic opening scorevs Cormack and Lehane grading. Can J Anesth 46, 987–990 (1999). https://doi.org/10.1007/BF03013137
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DOI: https://doi.org/10.1007/BF03013137