title: Effect of betamethasone, surfactant, and positive end-expiratory pressures on lung aeration at birth in preterm rabbits.
abstract: Antenatal glucocorticoids, exogenous surfactant, and positive end-expiratory pressure (PEEP) ventilation are commonly provided to preterm infants to enhance respiratory function after birth. It is unclear how these treatments interact to improve the transition to air-breathing at birth. We investigated the relative contribution of antenatal betamethasone, prophylactic surfactant, and PEEP (3 cmH2O) on functional residual capacity (FRC) and dynamic lung compliance (CDL) in preterm (28 day GA) rabbit kittens at birth. Kittens were delivered by cesarean section and mechanically ventilated. FRC was calculated from X-ray images, and CDLwas measured using plethysmography. Without betamethasone, PEEP increased FRC recruitment and CDLSurfactant did not further increase FRC, but significantly increased CDLBetamethasone abolished the benefit of PEEP on FRC, but surfactant counteracted this effect of betamethasone. These findings indicate that low PEEP levels are insufficient to establish FRC at birth following betamethasone treatment. However, surfactant reversed the effect of betamethasone and when combined, these two treatments enhanced FRC recruitment irrespective of PEEP level.
authors.affiliation: The Ritchie Centre, Hudson Institute for Medical Research, Melbourne, Australia; Department of Obstetrics and Gynaecology, Monash University, Clayton, Victoria, Australia;
authors.forename: Jessica R
authors.initials: JR
authors.lastname: Crawshaw
authors.affiliation: The Ritchie Centre, Hudson Institute for Medical Research, Melbourne, Australia; Department of Obstetrics and Gynaecology, Monash University, Clayton, Victoria, Australia; stuart.hooper@monash.edu.
authors.forename: Stuart B
authors.initials: SB
authors.lastname: Hooper
authors.affiliation: Division of Neonatology, Department of Pediatrics, Leiden University Medical Center, Leiden, the Netherlands;
authors.forename: Arjan B
authors.initials: AB
authors.lastname: Te Pas
authors.affiliation: The Ritchie Centre, Hudson Institute for Medical Research, Melbourne, Australia; Department of Obstetrics and Gynaecology, Monash University, Clayton, Victoria, Australia;
authors.forename: Beth A
authors.initials: BA
authors.lastname: Allison
authors.affiliation: The Ritchie Centre, Hudson Institute for Medical Research, Melbourne, Australia; Department of Obstetrics and Gynaecology, Monash University, Clayton, Victoria, Australia;
authors.forename: Megan J
authors.initials: MJ
authors.lastname: Wallace
authors.affiliation: The Ritchie Centre, Hudson Institute for Medical Research, Melbourne, Australia; Department of Obstetrics and Gynaecology, Monash University, Clayton, Victoria, Australia;
authors.forename: Lauren T
authors.initials: LT
authors.lastname: Kerr
authors.affiliation: Medical Imaging and Radiation Sciences, Monash University, Melbourne, Australia; Department of Medical Imaging, University of Saskatchewan, Saskatoon, Canada; and.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Lewis
authors.affiliation: The Royal Women's Hospital, Melbourne, Australia; and.
authors.forename: Colin J
authors.initials: CJ
authors.lastname: Morley
authors.affiliation: School of Physics and Astronomy, Monash University, Melbourne, Victoria, Australia.
authors.forename: Andrew F
authors.initials: AF
authors.lastname: Leong
authors.affiliation: School of Physics and Astronomy, Monash University, Melbourne, Victoria, Australia.
authors.forename: Marcus J
authors.initials: MJ
authors.lastname: Kitchen
keywords: betamethasone; functional residual capacity; positive end-expiratory pressure; preterm birth; surfactant