Impact of high- and low-flow nebulized saline on airway hydration and mucociliary transport

dc.contributor.authorKelly S
dc.contributor.authorValentine M
dc.contributor.authorChua WH
dc.contributor.authorTatkov S
dc.descriptionThis manuscript has recently been accepted for publication in the ERJ Open Research. It is published here in its accepted form prior to copyediting and typesetting by our production team. After these production processes are complete and the authors have approved the resulting proofs, the article will move to the latest issue of the ERJOR online.
dc.description.abstractBACKGROUND: Nebulised drugs, including osmotic agents and saline, are increasingly used during noninvasive respiratory support, including nasal high-flow therapy. The authors conducted an in vitro study to compare the hydration effect of nebulised isotonic 0.9% and hypertonic 7.0% saline on mucociliary transport. METHODS: In a perfused organ bath, 10 sheep tracheas were exposed to 7.5 mL nebulised 0.9% and 7.0% saline entrained into heated (38°C) and humidified air delivered at high and low flow (20 and 7 L·min-1, respectively). Simultaneous measurements of the airway surface liquid height, mucus transport velocity, cilia beat frequency and surface temperature were made over time. The data are presented as mean±sd. RESULTS: The airway surface liquid height increased significantly with both 0.9% and 7.0% saline: at low-flow by 37.2±10.0 µm and 152.7±10.9 µm, respectively, and at high-flow by 62.3±5.6 µm and 163.4±25.4 µm, respectively (p<0.001). Mucus velocity was increased by both 0.9% and 7.0% saline from a baseline of 8.2±0.8 mm·min-1 to 8.8±0.7 mm·min-1 and 17.1±0.5 mm·min-1, respectively, with low-flow and at high-flow to 9.8±0.02 mm·min-1 (p=0.04) and 16.9±0.5 mm·min-1 (p<0.05), respectively. Ciliary beating did not change with 0.9% saline, but declined from 13.1±0.6 Hz to 10.2±0.6 Hz and 11.1±0.6 Hz (p<0.05) with 7.0% saline at low- and high-flow, respectively. CONCLUSIONS: The findings demonstrate that nebulised isotonic 0.9% saline, like hypertonic 7.0% saline, significantly stimulates basal mucociliary transport, and the use of high-flow delivery had no significantly different hydration effects compared with low-flow delivery. Hypertonic 7.0% saline suppressed ciliary beating, indicating an increase in airway surface liquid osmolarity, which may have negative effects on the airway surface with frequent use.
dc.identifier.citationEuropean Respiratory Journal, 2023, 9 (2)
dc.publisherEuropean Respiratory Society
dc.relation.isPartOfEuropean Respiratory Journal
dc.rightsCopyright ©The authors 2023. This version is distributed under the terms of the Creative Commons Attribution Non-Commercial Licence 4.0. For commercial reproduction rights and permissions contact
dc.subject.anzsrc11 Medical and Health Sciences
dc.titleImpact of high- and low-flow nebulized saline on airway hydration and mucociliary transport
dc.typeJournal article
pubs.notesNot known
pubs.organisational-group/Massey University
pubs.organisational-group/Massey University/College of Health
pubs.organisational-group/Massey University/College of Health/School of Health Science
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