The Cormack-Lehane scale
[1] describes the best view of the glottis during laryngoscopy, with grades defined by the structures that can be seen, as follows:
- Grade 1 – Most of the glottis
- Grade 2 – Only the posterior extremity of the glottis
- Grade 3 – Only the epiglottis
- Grade 4 – Neither the glottis nor the epiglottis
A modified version
[2] of the Cormack-Lehane grading system divides Grade 2 into Grade 2a and 2b:
- Grade 2a – Only part of the vocal cords is visible
- Grade 2b – Only the arytenoids or the very posterior origin of the cords are visible
- Grade 3a - Epiglottis can be seen and lifted (eg, with a bougie)
- Grade 3b - Epiglottis can be seen but not lifted