Cormack-Lehane classification revisited.
BACKGROUND
The Cormack-Lehane (CL) classification is broadly used to describe laryngeal view during direct laryngoscopy. This classification, however, has been validated by only a few studies reporting inconclusive data concerning its reliability. This discrepancy between widespread use and limited evidence prompted us to investigate the knowledge about the classification among anaesthesiologists and its intra- and inter-observer reliability.


METHODS
One hundred and twenty interviews were performed at a major European anaesthesia congress. Participants were interviewed about their general knowledge on grading systems to classify laryngeal view during laryngoscopy and were subsequently asked to define the grades of the CL classification. Inter- and intra-observer reliabilities were tested in 20 anaesthesiologists well familiar with the CL classification, who performed 100 laryngoscopies in a full-scale patient simulator.


RESULTS
Although 89% of interviewed subjects claimed to know a classification to describe laryngeal view during laryngoscopy, 53% were able to name a classification. When specifically asked about the CL classification, 74% of the interviewed subjects stated to know this classification, whereas 25% could define all four grades correctly. In the simulator-based part of the study, inter-observer reliability was fair with a kappa coefficient of 0.35 and intra-observer reliability was poor with a kappa of 0.15.


CONCLUSIONS
The CL classification is poorly known in detail among anaesthesiologists and reproducibility even in subjects well familiar with this classification is limited.
Krage
R
R
Department of Anaesthesiology, VU University Medical Center, De Boelelaan 1117, Amsterdam, The Netherlands.
van Rijn
C
C
van Groeningen
D
D
Loer
S A
SA
Schwarte
L A
LA
Schober
P
P
D000328:Adult; D000368:Aged; D000776:Anesthesiology / Q000592:standards; D002983:Clinical Competence; D005260:Female; D006801:Humans; D007442:Intubation, Intratracheal / Q000379:methods; D007828:Laryngoscopy / Q000592:standards*; D007830:Larynx / Q000473:pathology*; D008297:Male; D008348:Manikins; D008875:Middle Aged; D015588:Observer Variation; D015203:Reproducibility of Results; D055815:Young Adult