Airway, Difficult/Critical — L.E.M.O.N. Method — Clinical Pathway: All Settings

Difficult/Critical Airway Clinical Pathway — All Settings

L.E.M.O.N. Method

The L.E.M.O.N. Method is often used to identify patients with potential difficult airway.

Physical Signs Less Difficult Airway More Difficult Airway
L
Look Externally
  • Normal face and neck
  • No face or neck pathology
  • Abnormal face shape
  • Sunken cheeks
  • Edentulous or “Buck” teeth
  • Receding mandible
  • “Bull- neck”
  • Narrow mouth
  • Obesity
  • Face or neck pathology
E
Evaluate the
3-3-2 rule
  • Mouth opens ≥ 3 fingers
  • Hyoid-chin distance ≥ 3 fingers
  • Thyroid cartilage-mouth floor distance ≥ 2 fingers
  • Mouth opens < 3 fingers
  • Hyoid-chin distance < 3 fingers
  • Thyroid cartilage-mouth floor distance < 2 fingers
M
Mallampati
  • Class I and II
  • Can see the soft palate, uvula, fauce,
  • +/- faucial pillars
  • Class III and IV
  • Can only see the hard palate +/- soft palate
  • +/- base of uvula
O
Obstruction
  • None
  • Pathology within or surrounding the upper airway
  • (e.g. peritonsillar abscess, epiglottitis)
  • Retropharyngeal abscess
N
Neck Mobility
  • Can flex and extend the neck normally
  • Limited range of motion of the neck