Effect of betamethasone, surfactant, and positive end-expiratory pressures on lung aeration at birth in preterm rabbits

Jessica Rose Crawshaw, Stuart Hooper, Arjan Te Pas, Beth Allison, Megan Wallace, Lauren Kerr, Rob Lewis, Colin Morley, Andrew Leong, Marcus Kitchen

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4 Citations (Scopus)


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 CDL was measured using plethysmography. Without betamethasone, PEEP increased FRC recruitment and CDL. Surfactant did not further increase FRC, but significantly increased CDL. Betamethasone 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.

Original languageEnglish
Pages (from-to)750-759
Number of pages10
JournalJournal of Applied Physiology
Issue number3
Publication statusPublished - 1 Sept 2016


  • Betamethasone
  • Functional residual capacity
  • Positive end-expiratory pressure
  • Preterm birth
  • Surfactant

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