title: Establishing functional residual capacity at birth: the effect of sustained inflation and positive end-expiratory pressure in a preterm rabbit model.
abstract: The effect of a 20 s sustained inflation (SI) and positive end-expiratory pressure (PEEP) on functional residual capacity (FRC) formation at birth were investigated. Preterm rabbit pups (28 d) were randomized at birth into four groups (n = 6 for each): 1) SI, PEEP 5 cm H2O, 2) no SI, PEEP 5 cm H2O, 3) no SI + no PEEP, 4) SI + no PEEP. FRC and tidal volume (Vt) were measured by plethysmography and uniformity of lung aeration by phase contrast x-ray imaging. Ventilation with a SI and PEEP uniformly aerated the lung and Vt and FRC were recruited by the first tidal inflation. Ventilation without a SI, with PEEP, gradually recruited Vt and FRC with each inflation but aeration was not uniform. Ventilation without a SI or PEEP, gradually recruited Vt, but no FRC. Ventilation with a SI, without PEEP, uniformly aerated the lung and recruited Vt but no FRC. FRC was greater with SI (p = 0.006) during the first minute, but was larger with PEEP than without PEEP throughout the first 7 min (p < 0.0005). Effects of PEEP and SI were additive. In ventilated preterm rabbits at birth, combining a SI and PEEP improved FRC formation and uniformity of lung aeration, but PEEP had the greatest influence.
authors.affiliation: Neonatal Services, Royal Women's Hospital, Melbourne, Victoria 3052, Australia. a.b.te_pas@lumc.nl
authors.forename: Arjan B
authors.initials: AB
authors.lastname: te Pas
authors.forename: Melissa
authors.initials: M
authors.lastname: Siew
authors.forename: Megan J
authors.initials: MJ
authors.lastname: Wallace
authors.forename: Marcus J
authors.initials: MJ
authors.lastname: Kitchen
authors.forename: Andreas
authors.initials: A
authors.lastname: Fouras
authors.forename: Robert A
authors.initials: RA
authors.lastname: Lewis
authors.forename: Naoto
authors.initials: N
authors.lastname: Yagi
authors.forename: Kentaro
authors.initials: K
authors.lastname: Uesugi
authors.forename: Susan
authors.initials: S
authors.lastname: Donath
authors.forename: Peter G
authors.initials: PG
authors.lastname: Davis
authors.forename: Colin J
authors.initials: CJ
authors.lastname: Morley
authors.forename: Stuart B
authors.initials: SB
authors.lastname: Hooper
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D005652:Functional Residual Capacity; D005865:Gestational Age; D008168:Lung / Q000000981:diagnostic imaging / Q000503:physiopathology*; D023421:Models, Animal; D010991:Plethysmography; D011175:Positive-Pressure Respiration; D047928:Premature Birth / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D012123:Pulmonary Ventilation; D011817:Rabbits; D011859:Radiography; D012121:Respiration, Artificial / Q000379:methods*; D013990:Tidal Volume; D013997:Time Factors