title: Serial measurements of lung function in a cohort of young children with bronchopulmonary dysplasia.
abstract: OBJECTIVE
  We aimed to prospectively and longitudinally measure lung function in a cohort of children with bronchopulmonary dysplasia (BPD) during their first 3 years of life.
  
  
  METHODS
  Forty-four children with BPD with a mean (+ or - SD) gestational age of 25.6 (+ or - 1.7) weeks and birth weight of 0.767 (+ or - 0.2) kg underwent serial measurements of lung function (maximum flow at functional residual capacity [V(max)FRC] and functional residual capacity [FRC]) at 6, 12, and 24 months after initial discharge from the neonatal care unit.
  
  
  RESULTS
  Compared with normative data, children with BPD had low partial expiratory airflow, measured by V(max)FRC, with mean z score (+ or - SD) of -1.92 (+ or - 1.04), -1.79 (+ or - 1.5), and -1.67 (+ or - 1.5) at 6, 12, and 24 months, respectively. Over time there was no significant improvement in z scores (P = .66), and 45% of the patients had a z score value of less than -2 (2 SDs below the mean) at the end of the study. FRC measurements steadily and significantly increased over time. Partial expiratory flow showed no correlation with gestational age, birth weight, or length of mechanical ventilation. Mean FRC was significantly higher in children who were using bronchodilators and inhaled steroids but showed no correlation with clinical symptoms. Bronchodilator response was initially present in 30% of the patients and declined to 20% at the end of the study.
  
  
  CONCLUSIONS
  During the first 3 years of life, children with mostly moderate-to-severe BPD continue to show significant abnormalities with airflow limitation according to lung-function testing.
authors.affiliation: Pulmonary Section, Department of Pediatrics, Baylor College of Medicine, Texas Children's Hospital, Houston, TX 77030, USA. akhoury@bcm.edu
authors.forename: Khoulood F
authors.initials: KF
authors.lastname: Fakhoury
authors.forename: Charles
authors.initials: C
authors.lastname: Sellers
authors.forename: E O'Brian
authors.initials: EO
authors.lastname: Smith
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Rama
authors.forename: Leland L
authors.initials: LL
authors.lastname: Fan
mesh_terms: D001997:Bronchopulmonary Dysplasia / Q000503:physiopathology*; D003430:Cross-Sectional Studies; D005260:Female; D005652:Functional Residual Capacity; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature / Q000502:physiology*; D016014:Linear Models; D008168:Lung / Q000503:physiopathology*; D008297:Male; D010991:Plethysmography; D011446:Prospective Studies; D012123:Pulmonary Ventilation; D012129:Respiratory Function Tests