ASSESSMENT OF AIRWAY VISUALIZATION - VALIDATION OF THE PERCENTAGE OF GLOTTIC OPENING (POGO) SCALE

Objective: Research defining optimal methods of intubation has been li mited by the lack of a validated outcome measure to assess airway visu alization. The objective of this study was to develop a reliable scale for the assessment of airway visualization during endotracheal intuba tion. Methods: This prospective study was performed to assess the intr a- and interphysician reliabilities of emergency physicians (EPs) for estimating the percentage of glottic opening (POGO) that is visualized during direct laryngoscopy. Using video images of laryngeal views obt ained from a commercially available video-tape, still slide images wer e prepared representing glottic openings ranging from 0% to 100%. Five EPs, blinded to study objective, reviewed 25 pairs of airway slides ( 50 slides total). For each slide, the physicians recorded the POGO and their scores using a modified Cormack-Lehane (MCL) scale, where grade I is a view of the full glottic opening, MCL grade II is a partial vi ew of the glottic opening, and MCL grade III is a view of the epiglott is only. Inter- and intraphysician reliabilities were assessed using t he kappa statistic (kappa) for MCL grade and intraclass correlation co efficient for the POGO scores. Results: For the POGO score, the degree of intrarater reliability was very goad, with an intraphysician corre lation of 0.85 and an interphysician correlation of 0.74. For the MCL score, the intraphysician concordance had a kappa of 0.71, and interph ysician concordance was also good, with a kappa of 0.59. Conclusion: B oth the modified version of the Cormack-Lehane grading classification and the POGO score have good interphysician and intraphysician reliabi lities. Because the POGO score can distinguish patients with large and small degrees of partial glottic visibility, it might provide a bette r outcome for assessing the difference between various intubation tech niques.