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Pressure-limited sustained inflation vs. gradual tidal inflations for resuscitation in preterm lambs

journal contribution
posted on 2023-05-20, 08:14 authored by Tingay, DG, Polglase, GR, Bhatia, R, Berry, CA, Kopotic, RJ, Kopotic, CP, Yong SongYong Song, Szyld, E, Jobe, AH, Pillow, JJ
Support of the mechanically complex preterm lung needs to facilitate aeration while avoiding ventilation heterogeneities: whether to achieve this gradually or quickly remains unclear. We compared the effect of gradual vs. constant tidal inflations and a pressure-limited sustained inflation (SI) at birth on gas exchange, lung mechanics, gravity-dependent lung volume distribution, and lung injury in 131-day gestation preterm lambs. Lambs were resuscitated with either 1) a 20-s, 40-cmH2O pressure-limited SI (PressSI), 2) a gradual increase in tidal volume (Vt) over 5-min from 3 ml/kg to 7 ml/kg (IncrVt), or 3) 7 ml/kg Vt from birth. All lambs were subsequently ventilated for 15 min with 7 ml/kg Vt with the same end-expiratory pressure. Lung mechanics, gas exchange and spatial distribution of end-expiratory volume (EEV), and tidal ventilation (electrical impedance tomography) were recorded regularly. At 15 min, early mRNA tissue markers of lung injury were assessed. The IncrVt group resulted in greater tissue hysteresivity at 5 min (P = 0.017; two-way ANOVA), higher alveolar-arterial oxygen difference from 10 min (P < 0.01), and least uniform gravity-dependent distribution of EEV. There were no other differences in lung mechanics between groups, and the PressSI and 7 ml/kg Vt groups behaved similarly throughout. EEV was more uniformly distributed, but Vt least so, in the PressSI group. There were no differences in mRNA markers of lung injury. A gradual increase in Vt from birth resulted in less recruitment of the gravity-dependent lung with worse oxygenation. There was no benefit of a SI at birth over mechanical ventilation with 7 ml/kg Vt.

History

Publication title

Journal of Applied Physiology

Volume

118

Issue

7

Pagination

890-897

ISSN

8750-7587

Department/School

Menzies Institute for Medical Research

Publisher

Amer Physiological Soc

Place of publication

9650 Rockville Pike, Bethesda, USA, Md, 20814

Rights statement

Copyright 2015 the American Physiological Society

Repository Status

  • Restricted

Socio-economic Objectives

Clinical health not elsewhere classified

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