title: Effect of posture on lung ventilation distribution and associations with structure in children with cystic fibrosis.
abstract: BACKGROUND
  We assessed the effect of posture on ventilation distribution and the impact on associations with structural lung disease.
  
  
  METHODS
  Multiple breath washout (MBW) was performed in seated and supine postures in 25 healthy children and 21 children with CF. Children with CF also underwent a chest CT scan. Functional residual capacity (FRC), lung clearance index (LCI) and moment ratios were calculated from the MBW test. CT scans were evaluated for CF-related structural lung disease.
  
  
  RESULTS
  FRC was lower in the supine than in the seated posture, whereas LCI was higher in the supine than in the seated posture. In children with CF, associations between LCI and the extent of structural lung disease were stronger when performed in the supine posture.
  
  
  CONCLUSIONS
  Body posture influences lung volumes and ventilation distribution in both healthy children and children with CF. MBW testing in the supine posture strengthened associations with structural lung damage.
authors.affiliation: Telethon Kids Institute, Subiaco, Western Australia, Australia; Centre for Child Health Research, University of Western Australia, Crawley, Western Australia, Australia; Cystic Fibrosis Research and Treatment Centre, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
authors.forename: Kathryn A
authors.initials: KA
authors.lastname: Ramsey
authors.affiliation: Telethon Kids Institute, Subiaco, Western Australia, Australia.
authors.forename: Caroline
authors.initials: C
authors.lastname: McGirr
authors.affiliation: Telethon Kids Institute, Subiaco, Western Australia, Australia; Centre for Child Health Research, University of Western Australia, Crawley, Western Australia, Australia; Respiratory Medicine, Princess Margaret Hospital for Children, Subiaco, Western Australia, Australia.
authors.forename: Stephen M
authors.initials: SM
authors.lastname: Stick
authors.affiliation: Telethon Kids Institute, Subiaco, Western Australia, Australia; Centre for Child Health Research, University of Western Australia, Crawley, Western Australia, Australia; School of Physiotherapy and Exercise Science, Curtin University, Bentley, Western Australia, Australia. Electronic address: Graham.Hall@telethonkids.org.au.
authors.forename: Graham L
authors.initials: GL
authors.lastname: Hall
authors.affiliation: Telethon Kids Institute, Subiaco, Western Australia, Australia; Centre for Child Health Research, University of Western Australia, Crawley, Western Australia, Australia.
authors.forename: Shannon J
authors.initials: SJ
authors.lastname: Simpson
mesh_terms: D000293:Adolescent; D001696:Biomechanical Phenomena / Q000502:physiology; D002648:Child; D003550:Cystic Fibrosis / Q000175:diagnosis / Q000503:physiopathology; D005260:Female; D005652:Functional Residual Capacity / Q000502:physiology*; D006801:Humans; D008168:Lung / Q000503:physiopathology; D008297:Male; D009079:Mucociliary Clearance / Q000502:physiology*; D011187:Posture / Q000502:physiology*; D012123:Pulmonary Ventilation / Q000502:physiology; D012129:Respiratory Function Tests / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods
keywords: Child; Computed tomography; Cystic fibrosis; Lung clearance index; Multiple breath washout; Posture; Ventilation distribution