title: Physiologic findings in children previously ventilator dependent at home due to bronchopulmonary dysplasia.
abstract: BACKGROUND
  Bronchopulmonary dysplasia (BPD) is the primary respiratory complication of premature birth. Some preterm newborns develop chronic respiratory failure, requiring home ventilator support. While physiologic measures have been described for prematurely born children, little is known about spirometric indices in patients with severe BPD who were previously ventilator dependent at home.
  
  
  METHODS
  We retrospectively reviewed medical charts of patients with severe BPD who were ventilator dependent at home. We excluded patients with other comorbidities that could contribute to the severity of BPD. Spirometry was performed when the patient was able to follow commands.
  
  
  RESULTS
  Between 1984 and 2012, within our severe BPD cohort who previously required home ventilator support, 19 patients were able to perform reproducible spirometry meeting ATS/ERS acceptability criteria. Ten (52.6%) were females, 13 (68.4%) were Caucasians. Mean age at liberation from ventilation was 2.4 years (C.I. 2.0, 2.9) and at decannulation was 3.5 years (C.I. 2.9, 4.0); median age at first reproducible spirometry measurement was 6.6 years (IQR: 4.9, 8.3). Spirometry results revealed significant airway obstruction, as demonstrated by Z-scores values of -1.5 (C.I. -2.5, -0.4) for FVC, -2.7 (C.I. -3.3, -1.9) for FEV1 , and -3.6 (C.I. -4.3, -2.9) for FEF25-75 . More so, serial spirometric measurements' slopes revealed that the airway obstruction remained static over time (FEV1 slope: -0.07, P-value: 0.2624; FVC slope: -0.01, P-value: 0.9064; and FEF25-75 : 0.0, P-value: 0.8532).
  
  
  CONCLUSIONS
  Extreme prematurity associated with severe BPD requiring home ventilator support carries significant risks of morbidity. These patients had substantially diminished respiratory function reflecting airflow abnormalities that remained static over time.
authors.affiliation: Department of Pediatrics, Riley Hospital for Children at Indiana University Health, Indianapolis, Indiana.
authors.forename: A Ioana
authors.initials: AI
authors.lastname: Cristea
authors.affiliation: Department of Pediatrics, Riley Hospital for Children at Indiana University Health, Indianapolis, Indiana.
authors.forename: Veda L
authors.initials: VL
authors.lastname: Ackerman
authors.affiliation: Department of Pediatrics, Riley Hospital for Children at Indiana University Health, Indianapolis, Indiana.
authors.forename: Nancy L
authors.initials: NL
authors.lastname: Swigonski
authors.affiliation: Department of Biostatistics, Indiana University School of Medicine, Indianapolis, Indiana.
authors.forename: Zhangsheng
authors.initials: Z
authors.lastname: Yu
authors.affiliation: Department of Biostatistics, Indiana University School of Medicine, Indianapolis, Indiana.
authors.forename: James E
authors.initials: JE
authors.lastname: Slaven
authors.affiliation: Department of Pediatrics, Riley Hospital for Children at Indiana University Health, Indianapolis, Indiana.
authors.forename: Stephanie D
authors.initials: SD
authors.lastname: Davis
mesh_terms: D000402:Airway Obstruction / Q000209:etiology / Q000503:physiopathology*; D001997:Bronchopulmonary Dysplasia / Q000150:complications / Q000503:physiopathology* / Q000628:therapy; D002675:Child, Preschool; D002908:Chronic Disease; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D019102:Infant, Very Low Birth Weight; D008297:Male; D011247:Pregnancy; D012119:Respiration; D012131:Respiratory Insufficiency / Q000150:complications / Q000503:physiopathology* / Q000628:therapy; D012189:Retrospective Studies; D013147:Spirometry
keywords: pulmonary function testing; spirometry; tracheostomy; ventilator-dependent children