title: Are Infants with Bronchopulmonary Dysplasia Prone to Gastroesophageal Reflux? A Prospective Observational Study with Esophageal pH-Impedance Monitoring.
abstract: OBJECTIVE
  To perform an observational cohort study with esophageal pH-multichannel intraluminal impedance (pH-MII) monitoring in symptomatic preterm infants with and without bronchopulmonary dysplasia (BPD).
  
  
  METHODS
  We prospectively studied 46 infants born ≤32 weeks gestational age: 12 infants with BPD and 34 infants without BPD. Each patient had symptoms consistent with gastroesophageal reflux and had 24-hour pH-MII, which were compared between BPD and non-BPD by univariate analysis and quantile regression analysis.
  
  
  RESULTS
  Demographic and clinical characteristics were similar between infants with and without BPD, except for fluid administration (145 vs 163 mL/kg/d, P = .003), length of stay (92 vs 69 days, P = .019), and time to achieve complete oral feeding (76 vs 51 days, P = .013). The analysis of 1104 hours of pH-MII tracings demonstrated that infants with BPD compared with infants without BPD had increased numbers of pH-only events (median number 21 vs 9) and a higher symptom sensitivity index for pH-only events (9% vs 4.9%); the number and characteristics of acid, weakly acid, nonacid and gas gastroesophageal reflux events, acid exposure, esophageal clearance, and recorded symptoms did not significantly differ between the 2 groups.
  
  
  CONCLUSIONS
  The increased number of (and sensitivity for) pH-only events among infants with BPD may be explained by several factors, including lower milk intake, impaired esophageal motility, and a peculiar autonomic nervous system response pattern.
authors.affiliation: Maternal and Child Department, Salesi Children's Hospital, Ancona, Italy.
authors.forename: Stefano
authors.initials: S
authors.lastname: Nobile
authors.affiliation: Maternal and Child Department, Salesi Children's Hospital, Ancona, Italy.
authors.forename: Carmine
authors.initials: C
authors.lastname: Noviello
authors.affiliation: Maternal and Child Department, Salesi Children's Hospital, Ancona, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Cobellis
authors.affiliation: Maternal and Child Department, Salesi Children's Hospital, Ancona, Italy.
authors.forename: Virgilio Paolo
authors.initials: VP
authors.lastname: Carnielli
mesh_terms: D001997:Bronchopulmonary Dysplasia / Q000150:complications*; D015331:Cohort Studies; D050782:Esophageal pH Monitoring; D004947:Esophagus / Q000503:physiopathology*; D005260:Female; D005764:Gastroesophageal Reflux / Q000175:diagnosis* / Q000209:etiology; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male; D011446:Prospective Studies