Table 2.

Grading scale for direct or video laryngoscopy (after Cormack-Lehane,16 Yentis17 and Cook18)

Grade	Description	Ease of laryngoscopy	Ease of tracheal intubation
Grade 1	All or most of vocal cords are visible	Easy	Intubation is generally non-problematic
Grade 2a	Partial view of vocal cords can be obtained
Grade 2b	Only the posterior cartilages are visible	Moderately difficult	Intubation is often manageable with adjuncts, e.g., a tracheal tube introducer (“bougie”) or rigid or semi-malleable stylet
Grade 3a	Only the epiglottis is visible, but it can be lifted off the posterior pharyngeal wall
Grade 3b	Only the epiglottis is visible, and it cannot be readily elevated	Failed	Intubation is often difficult or impossible; an alternate device is generally required
Grade 4	Neither the epiglottis nor glottis is visible