Airway Assessment

Table 20. Arne risk index.
Risk factors
Points of the
exact score
Points of the
simplified score
Previous knowledge of difficult intubation
No 0 0
Yes 3.28 10
Pathologies associated with difficult intubation
No 0 0
Yes 1.63 5
Clinical symptoms of airway pathology
No 0 0
Yes 0.98 3
Inter-incisor gap (IIG) and mandible luxation
IIG ≥ 5cm or ML > 0 0 0
3.5 < IG < 5 and ML = 0 1.09 3
IG < 3.5cm and ML < 0 4.12 13
Thyromental distance
≥ 6.5 cm 0 0
< 6.5cm 1.36 4
Maximum range of head and neck movement
Above 100° 0 0
90° ± 10° 0.65 2
Below 80° 1.46 5
Modified Mallampati Test
Class 1 0 0
Class 2 0.66 2
Class 3 1.93 6
Class 4 2.52 8
Total possible 15.35 48
NAGUIB MODEL
This model 62 uses logistic regression and includes thyromental distance, Mallampati score,
inter-incisor gap and height. This model is 82.5 per cent sensitive and 85.6 per cent specific
with an area under the receiver operating characteristic curve of 0.90.
27 Airway Assessment