Airway ultrasound for patients anticipated to have a difficult airway: Perspective for personalized medicine

Table 1 Cutoff values for predictors of a difficult airway

Predictor[12]	DDL or DMV	Cutoff value (sensitivity, specificity)
Distance from skin to epiglottis[22]	DDL, DMV	> 2.54 cm (82.0, 91.0)
Hyomental distance ratio[23] (extension/neutral position)	DDL	< 1.085 (75.0, 85.3)
Tongue base thickness	DMV	> 5.87 cm (85.0, 91.0)

DDL: Difficult direct laryngoscopy; DMV: Difficult mask ventilation.