The mnemonic
LEMON
What each word stands for
- LLook externally — small mandible, large tongue, short neck, facial trauma
- EEvaluate 3-3-2 — mouth opening, mandible length and hyoid to thyroid notch distances in fingerbreadths
- MMallampati class III or IV
- OObstruction or obesity — tumour, abscess, epiglottitis
- NNeck mobility — limited extension, for example cervical spine injury
Why it matters clinically
A positive assessment prompts a plan for a difficult airway before induction.
Where it stops being reliable
Predicts difficulty but has modest sensitivity; unexpected difficult airways still occur.
Teaching aid, still awaiting independent review. Confirm facts in a standard source.