Lung volume distribution in preterm infants on non-invasive high-frequency ventilation

Vincent D Gaertner; Andreas D Waldmann; Peter G Davis; Dirk Bassler; Laila Springer; Jessica Thomson; David Gerald Tingay; Christoph Martin Rüegger

doi:10.1136/archdischild-2021-322990

Lung volume distribution in preterm infants on non-invasive high-frequency ventilation

Arch Dis Child Fetal Neonatal Ed. 2022 Sep;107(5):551-557. doi: 10.1136/archdischild-2021-322990. Epub 2022 Jan 31.

Authors

Vincent D Gaertner¹, Andreas D Waldmann², Peter G Davis^{3

4

5}, Dirk Bassler¹, Laila Springer⁶, Jessica Thomson^{4

5}, David Gerald Tingay^{4

5

7}, Christoph Martin Rüegger⁸

Affiliations

¹ Newborn Research, Department of Neonatology, University Hospital and University of Zurich, Zurich, Switzerland.
² Department of Anesthesiology and Intensive Care Medicine, Rostock University Medical Center, Rostock, Germany.
³ Newborn Research Centre and Neonatal Services, The Royal Women's Hospital, Melbourne, Victoria, Australia.
⁴ Murdoch Children's Research Institute, Melbourne, Victoria, Australia.
⁵ University of Melbourne, Melbourne, Victoria, Australia.
⁶ Department of Neonatology, University Children's Hospital Tubingen, Tubingen, Germany.
⁷ Department of Neonatology, The Royal Children's Hospital Melbourne, Parkville, Victoria, Australia.
⁸ Newborn Research, Department of Neonatology, University Hospital and University of Zurich, Zurich, Switzerland christoph.rueegger@usz.ch.

PMID: 35101993
DOI: 10.1136/archdischild-2021-322990

Abstract

Introduction: Non-invasive high-frequency oscillatory ventilation (nHFOV) is an extension of nasal continuous positive airway pressure (nCPAP) support in neonates. We aimed to compare global and regional distribution of lung volumes during nHFOV versus nCPAP.

Methods: In 30 preterm infants enrolled in a randomised crossover trial comparing nHFOV with nCPAP, electrical impedance tomography data were recorded in prone position. For each mode of respiratory support, four episodes of artefact-free tidal ventilation, each comprising 30 consecutive breaths, were extracted. Tidal volumes (V_T) in 36 horizontal slices, indicators of ventilation homogeneity and end-expiratory lung impedance (EELI) for the whole lung and for four horizontal regions of interest (non-gravity-dependent to gravity-dependent; EELI_NGD, EELI_midNGD, EELI_midGD, EELI_GD) were compared between nHFOV and nCPAP. Aeration homogeneity ratio (AHR) was determined by dividing aeration in non-gravity-dependent parts of the lung through gravity-dependent regions.

Main results: Overall, 228 recordings were analysed. Relative V_T was greater in all but the six most gravity-dependent lung slices during nCPAP (all p<0.05). Indicators of ventilation homogeneity were similar between nHFOV and nCPAP (all p>0.05). Aeration was increased during nHFOV (mean difference (95% CI)=0.4 (0.2 to 0.6) arbitrary units per kilogram (AU/kg), p=0.013), mainly due to an increase in non-gravity-dependent regions of the lung (∆EELI_NGD=6.9 (0.0 to 13.8) AU/kg, p=0.028; ∆EELI_midNGD=6.8 (1.2 to 12.4) AU/kg, p=0.009). Aeration was more homogeneous during nHFOV compared with nCPAP (mean difference (95% CI) in AHR=0.01 (0.00 to 0.02), p=0.0014).

Conclusion: Although regional ventilation was similar between nHFOV and nCPAP, end-expiratory lung volume was higher and aeration homogeneity was slightly improved during nHFOV. The aeration difference was greatest in non-gravity dependent regions, possibly due to the oscillatory pressure waveform. The clinical importance of these findings is still unclear.

Keywords: intensive care units; neonatal; neonatology.

Publication types

Randomized Controlled Trial

MeSH terms

Continuous Positive Airway Pressure / methods
High-Frequency Ventilation* / methods
Humans
Infant
Infant, Newborn
Infant, Premature
Intermittent Positive-Pressure Ventilation / methods
Noninvasive Ventilation* / methods
Tidal Volume