There is no one perfect tool.

UK-style HAVNOT

H: History – including previous difficult airway
A: Anatomy – anatomical features that may cause difficulty
V: Visual clues – such as obesity and the presence of a beard
N: Neck mobility and accessibility (including immobilisation)
O: Opening of the mouth
T: Trauma

US-style: LEMON

LOOK (WOWWWWWW) - beard, receding chin...
Evaluate 3-3-2
- 3 fingers between incisors
- 3 fingers between hyoid and floor of mandible
- 2 fingers between base of chin and thyroid cartilage
Mallampati score
Obesity/fixed upper airway obstruction
Neck mobility
https://www.ncbi.nlm.nih.gov/books/NBK493235/

Mallampati definition

Class | - Soft palate, uvula, fauces, pillars visible
Class Il - soft palate, uvula, fauces visible
Class Ill - soft palate, base of uvula visible
Class IV - hard palate only visible

3-3-2 rule

Distance between the patient's incisor teeth should be at least 3 finger breadths (3) = mouth opening
Distance between hyoid bone and chin should be at least 3 finger breadths (3)
Distance between thyroid notch and floor of mouth should be at least 2 finger breadths (2) = thyromental distance

Cormack Lehane classification

If you've got to views on laryngoscopy then we're already committed sooooo

#airway