title: The Effect of Continuous Positive Airway Pressure in a Mouse Model of Hyperoxic Neonatal Lung Injury.
abstract: BACKGROUND
  Continuous positive airway pressure (CPAP) and supplemental oxygen have become the mainstay of neonatal respiratory support in preterm infants. Although oxygen therapy is associated with respiratory morbidities including bronchopulmonary dysplasia (BPD), the long-term effects of CPAP on lung function are largely unknown. We used a hyperoxia-induced mouse model of BPD to explore the effects of daily CPAP in the first week of life on later respiratory system mechanics.
  
  
  OBJECTIVE
  We wanted to test the hypothesis that daily CPAP in a newborn-mouse model of BPD improves longer-term respiratory mechanics.
  
  
  METHODS
  Mouse pups from C57BL/6 pregnant dams were exposed to room air (RA) or hyperoxia (50% O2, 24 h/day) for the first postnatal week with or without exposure to daily CPAP (6 cm H2O, 3 h/day). Respiratory system resistance (Rrs) and compliance (Crs) were measured following a subsequent 2-week period of RA recovery. Additional measurements included radial alveolar and macrophage counts.
  
  
  RESULTS
  Mice exposed to hyperoxia had significantly elevated Rrs, decreased Crs, reduced alveolarization and increased macrophage counts at 3 weeks when compared to RA-treated mice. Daily CPAP treatment significantly improved Rrs, Crs and alveolarization and decreased lung macrophage infiltration in the hyperoxia-exposed pups.
  
  
  CONCLUSIONS
  We have demonstrated that daily CPAP had a longer-term benefit on baseline respiratory system mechanics in a neonatal mouse model of BPD. We speculate that this beneficial effect of CPAP was the consequence of a decrease in the inflammatory response and resultant alveolar injury associated with hyperoxic lung injury in newborns.
authors.affiliation: Division of Neonatology, Department of Pediatrics, Rainbow Babies and Children's Hospital, Case Western Reserve University, Cleveland, Ohio, USA.
authors.forename: Brent
authors.initials: B
authors.lastname: Reyburn
authors.forename: Juliann M
authors.initials: JM
authors.lastname: Di Fiore
authors.forename: Thomas
authors.initials: T
authors.lastname: Raffay
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Martin
authors.forename: Y S
authors.initials: YS
authors.lastname: Prakash
authors.forename: Anjum
authors.initials: A
authors.lastname: Jafri
authors.forename: Peter M
authors.initials: PM
authors.lastname: MacFarlane
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001997:Bronchopulmonary Dysplasia / Q000628:therapy*; D045422:Continuous Positive Airway Pressure; D004195:Disease Models, Animal; D005260:Female; D018496:Hyperoxia / Q000150:complications*; D055370:Lung Injury / Q000628:therapy*; D008264:Macrophages / Q000473:pathology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010100:Oxygen / Q000009:adverse effects; D012129:Respiratory Function Tests
chemical_list: D010100:Oxygen