[Correlation of fractional exhaled nitric oxide in the upper and lower airways with the level of asthma control].

OBJECTIVE

To study the clinical value of combined measurement of fractional exhaled nitric oxide (FeNO) and nasal fractional exhaled nitric oxide (FnNO) and its correlation with the level of asthma control.

METHODS

A total of 120 children who were diagnosed with asthma from January to June, 2018 and were in the chronic persistent stage were enrolled as subjects. The childhood asthma control test (C-ACT) was performed for all the 120 children. According to the C-ACT score, these children were divided into 4 groups: complete control group with a C-ACT score of >23, partial control group with a C-ACT score of 20-23, and uncontrolled group with a C-ACT score of ≤19 (n=40 each). According to the presence or absence of allergic rhinitis, they were divided into 2 groups: non-rhinitis group with 55 children and rhinitis group with 65 children. A total of 40 children who underwent physical examination during the same period of time were enrolled as the control group. FeNO and FnNO levels were measured for all the 120 children.

RESULTS

The uncontrolled group had the highest level of FeNO, followed by the partial control group and the complete control group (P<0.05). The uncontrolled and partial control groups had a significantly higher level of FeNO than the control group (P<0.05). The uncontrolled and partial control groups had a significantly higher level of FnNO than the complete control and control groups (P<0.05). The rhinitis group had significantly higher FeNO and FnNO levels than the non-rhinitis group (P<0.05).

CONCLUSIONS

FeNO can be used to assess the level of asthma control in children, and its combination with FnNO may be useful for the evaluation of the degree of inflammation in the upper and lower airways and provide a basis for the combined treatment of the upper and lower airways.