151. Frequency distribution of breath sounds as an indicator of bronchoconstriction during histamine challenge test in asthmatic children
- Author
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Anssi Sovijärvi, Ritva Sorva, and L. Pekka Malmberg
- Subjects
Pulmonary and Respiratory Medicine ,Spirometry ,Male ,Adolescent ,Bronchoconstriction ,Provocation test ,Bronchial Provocation Tests ,chemistry.chemical_compound ,Forced Expiratory Volume ,medicine ,Humans ,Respiratory sounds ,Child ,Asthma ,Respiratory Sounds ,Analysis of Variance ,medicine.diagnostic_test ,business.industry ,medicine.disease ,Histamine Challenge Test ,Bronchodilatation ,chemistry ,Evaluation Studies as Topic ,Anesthesia ,Pediatrics, Perinatology and Child Health ,Regression Analysis ,Female ,medicine.symptom ,business ,Histamine - Abstract
In order to study changes in respiratory sounds associated with acute bronchoconstriction and -dilatation, breath sounds of 11 children with asthma (age range, 10–14 years) were recorded at the chest and at the trachea during histamine challenge test and after subsequent bronchodilatation. The changes in frequency spectra of breath sounds were compared with simultaneous changes in forced expiratory volume in 1 second (FEV1). In seven children who responded to histamine with a decrease in FEV, of more than 15%, there was a significant relationship between percentage change in FEV1 (ΔFEV1) and percentage change in median frequency (ΔF50) of expiratory breath sounds recorded at the chest (r = 0.865; β = −0.706, P = 0.0001) and at the trachea (r = 0.888; β = 1.12, P = 0.0001). The association between breath sound intensity and FEV1 was weaker. Based on ANOVA, the increase of F50 during the challenge test was significantly larger in children who responded to histamine than in those who were non-responsive (P = 0.0016). At the chest, a decrease of 15% in FEV1 corresponded to an increase of 8% in expiratory F50. The provocative dose of histamine inducing a decrease of 15% in FEV1 (PD15FEV1) and the provocative dose causing an increase of 8% in F50 (PD8F50) were significantly related (r = 0.927, P = 0.003). We conclude that spectral analysis of breath sounds can be used to indicate airway obstruction during bronchial challenge tests in children, and may be adapted for tests in pre-school children. The results suggest that the same mechanisms that induce airflow limitation due to inhaled histamine may generate an increase in frequency content of breath sounds in children with asthma.Pediatr Pulmonol. 1994;18:170–177. © 1994 Wiley-Liss, Inc.
- Published
- 1994