Korean J Pediatr.  2012 Sep;55(9):330-336. 10.3345/kjp.2012.55.9.330.

Fractional exhaled nitric oxide and forced expiratory flow between 25% and 75% of vital capacity in children with controlled asthma

• Yoon JY
• Woo SI
• Kim H
• Sun YH
• Hahn YS

• KMID: 2284391
• DOI: http://doi.org/10.3345/kjp.2012.55.9.330

Abstract

PURPOSE
Fractional exhaled nitric oxide (FeNO) and forced expiratory flow between 25% and 75% of vital capacity (FEF25-75) are not included in routine monitoring of asthma control. We observed changes in FeNO level and FEF25-75 after FeNO-based treatment with inhaled corticosteroid (ICS) in children with controlled asthma (CA).
METHODS
We recruited 148 children with asthma (age, 8 to 16 years) who had maintained asthma control and normal forced expiratory volume in the first second (FEV1) without control medication for > or =3 months. Patients with FeNO levels >25 ppb were allocated to the ICS-treated (FeNO-based management) or untreated group (guideline-based management). Changes in spirometric values and FeNO levels from baseline were evaluated after 6 weeks.
RESULTS
Ninety-three patients had FeNO levels >25 ppb. These patients had lower FEF25-75% predicted values than those with FeNO levels < or =25 ppb (P<0.01). After 6 weeks, the geometric mean (GM) FeNO level in the ICS-treated group was 45% lower than the baseline value, and the mean percent increase in FEF25-75 was 18.% which was greater than that in other spirometric values. There was a negative correlation between percent changes in FEF25-75 and FeNO (r=-0.368, P=0.001). In contrast, the GM FeNO and spirometric values were not significantly different from the baseline values in the untreated group.
CONCLUSION
The anti-inflammatory treatment simultaneously improved the FeNO levels and FEF25-75 in CA patients when their FeNO levels were >25 ppb.

Keyword

Nitric oxide; Spirometry; Inhaled corticosteroids; Asthma; Child

MeSH Terms

Asthma
Child
Forced Expiratory Volume
Humans
Nitric Oxide
Spirometry
Vital Capacity
Nitric Oxide