title: Lung volumes and distribution of ventilation in survivors to congenital diaphragmatic hernia (CDH) during infancy.
abstract: The assessment of lung volumes, particularly functional residual capacity (FRC), is crucial for understanding lung development during infancy in CDH patients.
  
  
  OBJECTIVE
  To evaluate changes in lung function during infancy in subjects with CDH treated with a "gentle ventilation" technique and delayed surgery strategy in the neonatal period.
  
  
  METHODS
  13 CDH infants were studied twice and compared with a population of 28 healthy infants (HI). Tidal-Volume (Vt), respiratory rate (RR) and time to peak expiratory flow/expiratory time ratio (tPTEF/Te) were measured with an ultrasonic flow meter; Compliance (Crs) and Resistance (Rrs) of the respiratory system were studied with the single occlusion technique; FRC and Lung Clearance Index (LCI), were assessed with the sulfur hexafluoride (SF6) wash-in/wash-out technique. The differences between the first (T1) and second (T2) measurement in the CDH group were assessed by the Student's t-test for paired values. For each set of measurement (T1 and T2) the values were compared with HI by Student's t-test.
  
  
  RESULTS
  Mean age at test was 7.5 +/- 5.2 months for HI, 4.5 +/- 2.5 at T1 and 11.9 +/- 4.5 months at T2 for CDH infants. At T1 there were no significant differences between CDH infants and HI in Vt, Crs, and FRC, while tPTEF/te ratio was lower and RR, Rrs, and LCI were higher in CDH patients than in HI. At T2 Vt, Crs, and FRC remained normal in CDH patients as well as RR that, at this time was not different between CDH and healthy infants; tPTEF/te remained below and Rrs and LCI remained above normal ranges, indicating a persistent impairment in lower airways patency.
  
  
  CONCLUSIONS
  Lung function in infants with severe CDH is characterized by a persistent impairment in airways patency and significant inhomogeneity of ventilation, suggesting a peripheral bronchial obstruction even if the other lung function tests are within normal ranges.
authors.affiliation: Department of Medical and Surgical Neonatology, Bambino Gesù Children's Hospital-IRCCS, Rome, Italy. dotta@opbg.net
authors.forename: Andrea
authors.initials: A
authors.lastname: Dotta
authors.forename: Sabrina
authors.initials: S
authors.lastname: Palamides
authors.forename: Annabella
authors.initials: A
authors.lastname: Braguglia
authors.forename: Francesco
authors.initials: F
authors.lastname: Crescenzi
authors.forename: Maria Paola
authors.initials: MP
authors.lastname: Ronchetti
authors.forename: Flaminia
authors.initials: F
authors.lastname: Calzolari
authors.forename: Barbara Daniela
authors.initials: BD
authors.lastname: Iacobelli
authors.forename: Pietro
authors.initials: P
authors.lastname: Bagolan
authors.forename: Carlo
authors.initials: C
authors.lastname: Corchia
authors.forename: Marcello
authors.initials: M
authors.lastname: Orzalesi
mesh_terms: D005260:Female; D005500:Follow-Up Studies; D006548:Hernia, Diaphragmatic / Q000503:physiopathology* / Q000628:therapy; D065630:Hernias, Diaphragmatic, Congenital; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008168:Lung / Q000254:growth & development*; D008176:Lung Volume Measurements; D008297:Male; D009929:Organ Size; D017741:Survivors