Risk Factors of Chhina et al for Difficult Intubation

Patient selection: intubation

Parameters:

(1) modified Mallampati scale

(2) head-neck movement, as flexion from maximum extension in degrees

(3) neck circumference at the level of the thyroid cartilage in cm

where:

• A large neck circumference is also a risk factor for obstructive sleep apnea.

number of risk factors =

= SUM(points for the 3 parameters)

Interpretation:

• minimum number of risk factors: 0

• maximum number of risk factors: 3

Performance:

• A multivariate model based on these 3 parameters had a sensitivity of 75% and specificity of 82% for difficult intubation.

• The area under the ROC curve for the model was 0.90.