title: Sensitivity of newly defined impulse oscillometry indices in preschool children.
abstract: Early origins of chronic obstructive pulmonary disease have been recognized. Impulse oscillometry (IOS) is suitable for assessment of lung function also in preschool children, and some novel indices have been connected to assessment of small airway function. However, limited data exist on the sensitivity of these new indices to detect lung function deficits in young symptomatic children.
  
  
  
  IOS measurements of 103 healthy preschool children were evaluated to establish reference equations for the difference between respiratory resistance at 5 and 20 Hz (R5-20), the relative difference of R5-20 (R5-20%), and area under the reactance curve (AX). Thereafter, IOS results of children with late-onset troublesome lung symptoms (n = 20), a history of early wheeze (n = 37), or a history of bronchopulmonary dysplasia (BPD, n = 8) were compared to healthy children.
  
  
  
  None of the patient groups differed from healthy regarding respiratory resistance at 5 Hz (R5), and only children with a history of BPD differed from healthy regarding respiratory reactance at 5 Hz (X5). In contrast, z-scores of R5-20, R5-20%, and AX were significantly higher in all patient groups than in healthy children (P < 0.001), showing improved sensitivity (20-55%) compared to R5 and X5 (5-6%).
  
  
  
  R5-20, R5-20%, and AX are superior to conventional IOS parameters in distinguishing children with current or past lower respiratory tract symptoms from healthy, and may prove valuable for screening early lung function deficits. Pediatr Pulmonol. 2017;52:598-605. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Pediatric Unit of the Department of Allergology, Skin and Allergy Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.|Faculty of Medicine, University of Helsinki, Helsinki, Finland.
authors.forename: Hanna
authors.initials: H
authors.lastname: Knihtilä
authors.affiliation: Pediatric Unit of the Department of Allergology, Skin and Allergy Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.
authors.forename: Anne
authors.initials: A
authors.lastname: Kotaniemi-Syrjänen
authors.affiliation: Pediatric Unit of the Department of Allergology, Skin and Allergy Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.
authors.forename: Anna S
authors.initials: AS
authors.lastname: Pelkonen
authors.affiliation: Pediatric Unit of the Department of Allergology, Skin and Allergy Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.
authors.forename: Satu
authors.initials: S
authors.lastname: Kalliola
authors.affiliation: Pediatric Unit of the Department of Allergology, Skin and Allergy Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.|Faculty of Medicine, University of Helsinki, Helsinki, Finland.
authors.forename: Mika J
authors.initials: MJ
authors.lastname: Mäkelä
authors.affiliation: Pediatric Unit of the Department of Allergology, Skin and Allergy Hospital, University of Helsinki and Helsinki University Hospital, Helsinki, Finland.
authors.forename: L Pekka
authors.initials: LP
authors.lastname: Malmberg
mesh_terms: D000403:Airway Resistance / Q000502:physiology; D001997:Bronchopulmonary Dysplasia / Q000175:diagnosis* / Q000503:physiopathology; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008168:Lung / Q000503:physiopathology*; D008297:Male; D009991:Oscillometry / Q000379:methods*; D029424:Pulmonary Disease, Chronic Obstructive / Q000175:diagnosis* / Q000503:physiopathology; D012129:Respiratory Function Tests
keywords: asthma and early wheeze; impulse oscillometry; pulmonary function testing; reference values; small airways