Table 1:
Hay reference values according to age.
Values of FeNO (ppb), patients ≥ 12 years of age
Low
Intermediate
High
< 25
25 - 50
> 50
Values of FeNO (ppb), patients < 12 years of age
< 20
20 - 35
> 35
Source: Dweik RA, et al. [
21
].