title: Sustained inflation at birth did not alter lung injury from mechanical ventilation in surfactant-treated fetal lambs.
abstract: BACKGROUND
  Sustained inflations (SI) are used with the initiation of ventilation at birth to rapidly recruit functional residual capacity and may decrease lung injury and the need for mechanical ventilation in preterm infants. However, a 20 second SI in surfactant-deficient preterm lambs caused an acute phase injury response without decreasing lung injury from subsequent mechanical ventilation.
  
  
  OBJECTIVE
  A 20 second SI at birth will decrease lung injury from mechanical ventilation in surfactant-treated preterm fetal lambs.
  
  
  METHODS
  The head and chest of fetal sheep at 126±1 day GA were exteriorized, with tracheostomy and removal of fetal lung fluid prior to treatment with surfactant (300 mg in 15 ml saline). Fetal lambs were randomized to one of four 15 minute interventions: 1) PEEP 8 cmH2O; 2) 20 sec SI at 40 cmH2O, then PEEP 8 cmH2O; 3) mechanical ventilation with 7 ml/kg tidal volume; or 4) 20 sec SI then mechanical ventilation at 7 ml/kg. Fetal lambs remained on placental support for the intervention and for 30 min after the intervention.
  
  
  RESULTS
  SI recruited a mean volume of 6.8±0.8 mL/kg. SI did not alter respiratory physiology during mechanical ventilation. Heat shock protein (HSP) 70, HSP60, and total protein in lung fluid similarly increased in both ventilation groups. Modest pro-inflammatory cytokine and acute phase responses, with or without SI, were similar with ventilation. SI alone did not increase markers of injury.
  
  
  CONCLUSIONS
  In surfactant treated fetal lambs, a 20 sec SI did not alter ventilation physiology or markers of lung injury from mechanical ventilation.
authors.affiliation: Division of Neonatology, Cardinal Glennon Children's Medical Center, Saint Louis University, Saint Louis, Missouri, United States of America.
authors.forename: Noah H
authors.initials: NH
authors.lastname: Hillman
authors.affiliation: School of Women's and Infants' Health, University of Western Australia, Perth, Western Australia, Australia.
authors.forename: Matthew W
authors.initials: MW
authors.lastname: Kemp
authors.affiliation: School of Women's and Infants' Health, University of Western Australia, Perth, Western Australia, Australia.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Miura
authors.affiliation: Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio, United States of America; School of Women's and Infants' Health, University of Western Australia, Perth, Western Australia, Australia.
authors.forename: Suhas G
authors.initials: SG
authors.lastname: Kallapur
authors.affiliation: Division of Pulmonary Biology, Cincinnati Children's Hospital Medical Center, University of Cincinnati, Cincinnati, Ohio, United States of America; School of Women's and Infants' Health, University of Western Australia, Perth, Western Australia, Australia.
authors.forename: Alan H
authors.initials: AH
authors.lastname: Jobe
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001992:Bronchoalveolar Lavage Fluid / Q000737:chemistry; D018834:Chaperonin 60 / Q000378:metabolism; D016207:Cytokines / Q000235:genetics / Q000378:metabolism; D005260:Female; D005652:Functional Residual Capacity / Q000187:drug effects / Q000502:physiology; D018507:Gene Expression Regulation, Developmental; D005865:Gestational Age; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism; D007327:Insufflation / Q000379:methods*; D008168:Lung / Q000187:drug effects* / Q000378:metabolism / Q000503:physiopathology; D055370:Lung Injury / Q000196:embryology / Q000209:etiology / Q000503:physiopathology*; D010920:Placenta / Q000502:physiology; D011247:Pregnancy; D012121:Respiration, Artificial / Q000009:adverse effects / Q000379:methods*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012756:Sheep; D013501:Surface-Active Agents / Q000494:pharmacology*; D013997:Time Factors
chemical_list: D018834:Chaperonin 60; D016207:Cytokines; D018840:HSP70 Heat-Shock Proteins; D013501:Surface-Active Agents