Assessment of small airway function and reversibility in symptom-controlled asthma in pediatric patients

The goals of asthma management aim to control the symptoms and minimize future risk. There is, however, an option to stop controller medication if the patient has been well-controlled for at least 6-12 months. To assess control, both clinical symptom assessment and lung function should be monitored periodically. In practical clinical practice of pediatric patients, lung function is not available at all health centers.

to determine lung function with a focus on small airway function and the risk of reversibility among children who have been symptom-controlled.

Our participants were symptom-controlled asthmatic children according to GINA Guideline for at least 6 months with low dose inhaled corticosteroid. Written informed-consent was given by the parents and the children. They performed a self-evaluated symptom-controlled test (C-ACT) and a spirometric assessment. Abnormal lung function was defined as FEV1±80%, FEV1/FVC < 80%, and FEF25-75 <65% predicted. Airway reversibility was determined by the change of FEV1 >12% and FEF25-75 >30% post bronchodilator.

Forty children (65% male) were enrolled. Age ranged between 6.7 and 15.0 years. The mean C-ACT score was 25.2 ± 1.7. Spirometry results were: mean FEV1 84.0 %, FEV1/FVC 87.8%, and FEF25-75 85.5% predicted. Normal FEV1 was found among 72.5% of participants compared to normal FEF25-75 in 87.5%. Among the abnormal FEV1 and FEF25-75, all were of mild severity as 10% retained airway reversibility.

Children with well-controlled asthma, based on their symptom assessment, may have persistent abnormal lung function. Spirometry should be performed before considering cessation of controller medication.