Will This Patient Be Difficult to Intubate?

A previously healthy 27-year-old woman was scheduled for elective cholecystectomy. Examination of her airway demonstrated a modified Mallampati score of 2; however, she was unable to bite her upper lip with her lower incisors.

Is she a difficult airway ? Which test has the best +LR?

As a non- anesthesiologist , I definitely learned something new here. The widely used modified Mallampati score (>or equal then 3) had only a +LR= 4.1. The physical examination findings that best predicted a difficult intubation included a grade of class 3 on the upper lip bite test, +LR = 14

In this systematic review in the September JAMA LN issue, several physical findings increased the likelihood of difficult intubation. The best predictors were an inability to bite the upper lip with the lower incisors, a short hyomental distance, retrognathia, or a combination of findings based on the Wilson score. No risk factor or physical finding consistently ruled out a potentially difficult intubation.

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 An abnormal upper lip bite test, which is easily assessed by clinicians, raises the probability of difficult intubation from 10% to greater than 60% for the average-risk patient