Spirometry and FeNO in Children with Mild-Moderate and Severe Asthma

Abstract

Introduction: severe asthma (S) is defined by the need of high dose inhaled steroids (GINA). Physiopathological differences between S and mild/moderate (MM) asthma are not clear.

Objective: to compare FeNO and spirometry values between MM and S asthmatic children.

Methods: 12 months, multicentric, prospective, cross-sectional study. Children with MM and S asthma followed at Pediatric Pulmonology Section, General University Hospital, and S followed at a National Pediatric Hospital were included. Asthma severity was classified according to GINA.

Asthma Control Test (ACT), physical examination, FeNO, and spirometry with bronchodilator test (BDR) were performed. Results were presented as medians and interquartile range (IQR); Student t test and Mann-Whitney were used. Significant difference: p < 0.05.

Results: 163 children [median 10 (6-18 years), 82 M], MM 51% (n=84) and S 49% (n=79). According to ACT, all MM children had well controlled asthma (G1). Of the S children, 61 (77%) had well control (G2) and 18 (23%) uncontrolled asthma (G3).

FeNO median (IQR) was G1 25 ppb (14-42), G 22 ppb (13-36) and G3 42 ppb (26-91); (1 vs 2 p=0.35; 1 vs 3 p= 0.01 and 2 vs 3 p= 0.006).

VEF1 median (IQR) G1 104% (91-116), G2 106% (95-117), and G3 98% (90-108) (p NS).

FEF 25-75 median (IQR) G1 97% (77-112), G2 88% (66-107) and G3 72% (61-92) (1 vs 2 p= 0.03; 1 vs 3 p= 0.007 and 2 vs 3 NS).

Conclusion: high FeNO values (inflammation) were related to poor asthma control in S and FEF 25-75 was associated to severity according to GINA.