title: New reference ranges for interpreting forced expiratory manoeuvres in infants and implications for clinical interpretation: a multicentre collaboration.
abstract: The raised volume rapid thoracoabdominal compression (RVRTC) technique is commonly used to obtain full forced expiratory manoeuvres from infants, but reference equations derived from 'in-house' equipment have been shown to be inappropriate for current commercially available devices.
  
  
  OBJECTIVE
  To explore the impact of equipment differences on RVRTC outcomes, derive robust equipment-specific RVRTC reference ranges and investigate their potential clinical impact on data interpretation.
  
  
  METHODS
  RVRTC data from healthy subjects using Jaeger BabyBody or the 'Respiratory Analysis Software Program, RASP' systems were collated from four centres internationally. Data were excluded if gestational age <37 weeks or birth weight <2.5 kg. Reference equations for RVRTC outcomes were constructed using the LMS (lambda-mu-sigma) method, and compared with published equations using data from newborn screened infants with cystic fibrosis (CF).
  
  
  RESULTS
  RVRTC data from 429 healthy infants (50.3% boys; 88% white infants) on 639 occasions aged 4-118 weeks were available. When plotted against length, flows were significantly higher with RASP than Jaeger, requiring construction of separate equipment-specific regression equations. When comparing results derived from the new equations with those from widely used published equations based on different equipments, discrepancies in forced expiratory volumes and flows of up to 2.5 z-scores were observed, the magnitude of which increased with age. According to published equations, 25% of infants with CF fell below the 95% limits of normal for FEV0.5, compared with only 10% when using the new equations.
  
  
  CONCLUSIONS
  Use of equipment-specific prediction equations for RVRTC outcomes will enhance interpretation of infant lung function results; particularly during longitudinal follow-up.
authors.affiliation: Respiratory, Critical Care & Anaesthesia section in IIIP Programme, UCL, Institute of Child Health, London, UK.
authors.forename: Sooky
authors.initials: S
authors.lastname: Lum
authors.affiliation: Respiratory, Critical Care & Anaesthesia section in IIIP Programme, UCL, Institute of Child Health, London, UK.
authors.forename: Vassiliki
authors.initials: V
authors.lastname: Bountziouka
authors.affiliation: Department of Clinical Epidemiology, Nutrition and Biostatistics Section, UCL, Institute of Child Health, UK.
authors.forename: Angela
authors.initials: A
authors.lastname: Wade
authors.affiliation: Respiratory, Critical Care & Anaesthesia section in IIIP Programme, UCL, Institute of Child Health, London, UK Respiratory Medicine, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK.
authors.forename: Ah-Fong
authors.initials: AF
authors.lastname: Hoo
authors.affiliation: Respiratory, Critical Care & Anaesthesia section in IIIP Programme, UCL, Institute of Child Health, London, UK Respiratory Medicine, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK.
authors.forename: Jane
authors.initials: J
authors.lastname: Kirkby
authors.affiliation: Paediatric Pulmonology Unit, Hospital Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Moreno-Galdo
authors.affiliation: Paediatric Pulmonology Unit, Hospital Vall d'Hebron, Universitat Autònoma de Barcelona, Barcelona, Spain.
authors.forename: Ines
authors.initials: I
authors.lastname: de Mir
authors.affiliation: Division of Paediatric Respiratory Medicine, Donostia University Hospital, San Sebastian, Spain Department of Paediatrics, University of the Basque Country, San Sebastian, Spain.
authors.forename: Olaia
authors.initials: O
authors.lastname: Sardon-Prado
authors.affiliation: Division of Paediatric Respiratory Medicine, Donostia University Hospital, San Sebastian, Spain.
authors.forename: Paula
authors.initials: P
authors.lastname: Corcuera-Elosegui
authors.affiliation: School of Medicine and Public Health, University of Newcastle, Newcastle, Australia Department of Paediatric Respiratory & Sleep Medicine, John Hunter Children's Hospital, Newcastle, Australia.
authors.forename: Joerg
authors.initials: J
authors.lastname: Mattes
authors.affiliation: Centro de Alergia, CUF Descobertas Hospital, Lisbon, Portugal CEDOC, NOVA Medical School, Lisbon, Portugal.
authors.forename: Luis Miguel
authors.initials: LM
authors.lastname: Borrego
authors.affiliation: Respiratory, Critical Care & Anaesthesia section in IIIP Programme, UCL, Institute of Child Health, London, UK Respiratory Medicine, Great Ormond Street Hospital for Children NHS Foundation Trust, London, UK.
authors.forename: Gwyneth
authors.initials: G
authors.lastname: Davies
authors.affiliation: Respiratory, Critical Care & Anaesthesia section in IIIP Programme, UCL, Institute of Child Health, London, UK.
authors.forename: Janet
authors.initials: J
authors.lastname: Stocks
mesh_terms: D003550:Cystic Fibrosis / Q000175:diagnosis / Q000503:physiopathology*; D045853:Exhalation; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume / Q000502:physiology*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008168:Lung / Q000503:physiopathology*; D008297:Male; D012016:Reference Values; D012189:Retrospective Studies; D012720:Severity of Illness Index; D014797:Vital Capacity / Q000502:physiology
keywords: Paediatric Lung Disaese; Respiratory Measurement