title: Lung function by impulse oscillometry at age 5-7 years after bronchiolitis at age 0-6 months.
abstract: BACKGROUND
  Viral bronchiolitis in infancy has been associated with increased bronchial reactivity and reduced lung function in later childhood and even in adulthood. However, lung function at preschool age is less studied, mainly due to technical difficulties. The purpose of the study was to evaluate lung function and bronchial reactivity at preschool age in children who were hospitalized for bronchiolitis in early infancy.
  
  
  METHODS
  Airway resistance and reactance, and bronchial reactivity to exercise were studied with impulse oscillometry (IOS) at the mean age of 6.3 years in 103 children hospitalized for bronchiolitis at less than 6 months of age.
  
  
  RESULTS
  In baseline lung-function measurement, resistance (n = 8; 7.8%) or reactance (19; 18.4%) at 5 Hz were pathological in 20% of children compared to Finnish population-based height-adjusted reference values. Increased bronchial reactivity by exercise challenge (5; 4.9%) or bronchodilatation (11; 10.7%) tests was present in 16%. Irreversible changes were revealed in only one case.
  
  
  CONCLUSIONS
  Though reduced lung function and increased airway reactivity were rather common, evidence for persistent lung function reduction was rare, less than 1%, at preschool age in children hospitalized for bronchiolitis caused mainly by respiratory syncytial virus at age less than 6 months.
authors.affiliation: Tampere Center for Child Health Research, Tampere University and University Hospital, Tampere, Finland.
authors.forename: Eero
authors.initials: E
authors.lastname: Lauhkonen
authors.forename: Petri
authors.initials: P
authors.lastname: Koponen
authors.forename: Kirsi
authors.initials: K
authors.lastname: Nuolivirta
authors.forename: Marita
authors.initials: M
authors.lastname: Paassilta
authors.forename: Jyri
authors.initials: J
authors.lastname: Toikka
authors.forename: Matti
authors.initials: M
authors.lastname: Korppi
mesh_terms: D000403:Airway Resistance / Q000502:physiology; D016535:Bronchial Hyperreactivity / Q000503:physiopathology; D001990:Bronchiolitis, Viral / Q000503:physiopathology*; D001993:Bronchodilator Agents; D002648:Child; D002675:Child, Preschool; D015444:Exercise / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009991:Oscillometry / Q000379:methods*
chemical_list: D001993:Bronchodilator Agents
keywords: asthma & early wheeze; bronchial hyper-reactivity; pulmonary function testing; viral bronchiolitis