title: Breathing patterns in preterm and term infants immediately after birth.
abstract: There is limited data describing how preterm and term infants breathe spontaneously immediately after birth. We studied spontaneously breathing infants >or=29 wk immediately after birth. Airway flow and tidal volume were measured for 90 s using a hot wire anemometer attached to a facemask. Twelve preterm and 13 term infants had recordings suitable for analysis. The median (interquartile range) proportion of expiratory braking was very high in both groups (preterm 90 [74-99] vs. term 87 [74-94]%; NS). Crying pattern was the predominant breathing pattern for both groups (62 [36-77]% vs. 64 [46-79]%; NS). Preterm infants showed a higher incidence of expiratory hold pattern (9 [4-17]% vs. 2 [0-6]%; p = 0.02). Both groups had large tidal volumes (6.7 [3.9] vs. 6.5 [4.1] mL/kg), high peak inspiratory flows (5.7 [3.8] vs. 8.0 [5] L/min), lower peak expiratory flow (3.6 [2.4] vs. 4.8 [3.2] L/min), short inspiration time (0.31 [0.13] vs. 0.32 [0.16] s) and long expiration time (0.93 [0.64] vs. 1.14 [0.86] s). Directly after birth, both preterm and term infants frequently brake their expiration, mostly by crying. Preterm infants use significantly more expiratory breath holds to defend their lung volume.
authors.affiliation: Division of Newborn Services, Royal Women's Hospital, Carlton, Victoria 3053, Australia. arjan.tepas@rwh.org.au
authors.forename: Arjan B
authors.initials: AB
authors.lastname: te Pas
authors.forename: Connie
authors.initials: C
authors.lastname: Wong
authors.forename: C Omar F
authors.initials: CO
authors.lastname: Kamlin
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Dawson
authors.forename: Colin J
authors.initials: CJ
authors.lastname: Morley
authors.forename: Peter G
authors.initials: PG
authors.lastname: Davis
mesh_terms: D001724:Birth Weight; D003448:Crying / Q000502:physiology; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D047928:Premature Birth / Q000503:physiopathology*; D012123:Pulmonary Ventilation / Q000502:physiology*; D015656:Respiratory Mechanics / Q000502:physiology*; D013990:Tidal Volume / Q000502:physiology*