High-pitched breath sounds indicate airflow limitation in asymptomatic asthmatic children

• Published in: Respirology (Carlton, Vic.) Vic.), 2009-04, Vol.14 (3), p.399-403
• Main Authors: HABUKAWA, Chizu, NAGASAKA, Yukio, MURAKAMI, Katsumi, TAKEMURA, Tsukasa
• Format: Article
• Language: English
• Subjects: Adolescent; airway obstruction; Androstadienes - therapeutic use; asthma; Asthma - diagnosis; Asthma - drug therapy; Asthma - physiopathology; Bronchodilator Agents - therapeutic use; Child; children; Female; Fluticasone; Humans; lung sound; Male; Predictive Value of Tests; Respiratory Function Tests; Respiratory Mechanics - physiology; Respiratory Sounds - physiopathology; Severity of Illness Index; Sound Spectrography; Spirometry; Young Adult
• ISSN: 1323-7799; 1440-1843
• DOI: 10.1111/j.1440-1843.2008.01465.x

ABSTRACT Background and objective:  Asthmatic children may have airway dysfunction even when asymptomatic, indicating that their long‐term treatment is less than optimal. Although airway dysfunction can be identified on lung function testing, performing these tests can be difficult in infants. We studied whether breath sounds reflect subtle airway dysfunction in asthmatic children. Methods:  The highest frequency of inspiratory breaths sounds (HFI) and the highest frequency of expiratory breath sounds (HFE) were measured in 131 asthmatic children while asymptomatic and with no wheezes for more than 2 weeks. No child was being treated with inhaled corticosteroids (ICS). Breath sounds were recorded and analysed by sound spectrography and compared with spirometric parameters. After initial evaluation, cases with more than step 2 (mild persistent) asthma were treated using inhaled fluticasone (100–200 µg/day) for 1 month, and then breath sound analysis and pulmonary function testing were repeated. Results:  On initial evaluation, HFI correlated with the percentage of predicted FEF50 (%FEF50), (r = −0.45, P