(1073) Reliability of the Cormack-Lehane Classification: A Scoping Review

Introduction: The Cormack-Lehane classification grades the quality of laryngoscopy during tracheal intubation. It is associated with first-attempt success among critically ill patients; therefore, it is widely used to measure the difficulty of laryngoscopy and intubation. Few studies have evaluated the reliability of the classification. We aimed to assess the size and scope of studies investigating the inter-rater reliability of the Cormack-Lehane classification by performing a scoping review.

Methods: We searched PubMed and Google Scholar for studies evaluating the inter-rater reliability of the Cormack-Lehane classification between at least two clinician raters assessing the same airway and reporting a kappa statistic value. There were no exclusions on patient demographics, study setting, laryngoscopic device, or clinician training level.

Results: Of the 2,264 potential studies identified from our search, seven studies met our eligibility criteria. Kappa statistic values for inter-rater reliability ranged from 0.020 to 0.87. Studies utilized still images (n=4), videos (n=2), and real-time laryngoscopy (n=2) of operating room patients (n=4), clinic patients (n=1), and mannequins (n=2) to assess Cormack-Lehane view reliability by emergency, anesthesia, sleep, otolaryngology, pediatric, neonatal attending physicians, residents, and fellows as well as paramedics and medical students. Direct (n=5), video (n=2), and flexible fiberoptic (n=1) laryngoscopes were used. We did not identify any studies including critically ill patients, nor using real-time laryngoscopy on live patients.

Conclusions: Studies assessing the reliability of the Cormack-Lehane classification are limited with heterogeneous methods and do not generalize to critically ill patients.