Serial fluid overload assessment in critically ill children using chest ultrasound (FOCUS): a prospective cohort study
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Background
Excessive intravenous fluid administration can prolong invasive mechanical ventilation (IMV) in critically ill children. In ventilated adults, lung point-of-care ultrasound (POCUS) is increasingly used to assess fluid status. We aimed to assess the correlation between B-lines on daily lung POCUS in ventilated children, contemporaneous oxygenation markers and cumulative fluid balance.
Methods
This prospective single-centre observational cohort study was conducted between March 2023 and May 2024. Doctors and physiotherapists utilised POCUS to measure B-line scores (BLS) across 8 zones in children expected to remain ventilated beyond 24 h. Daily scans were conducted until ventilation liberation or IMV day 7. Contemporaneous oxygen saturation (SpO2):fraction of inspired oxygen (FiO2) (SF) ratio and fluid balance (cumulative fluid balance [CFB] and clinical oedema) were measured. Mixed effects linear regression was used to assess the association between daily B-line scores and SF ratio, CFB and oedema.
Results
Thirty seven children were enrolled (78 scans) with median age 18 months (IQR 9–44). The most common admission reason was respiratory (76%, n = 28). Scans took a median of 10 min (IQR 5–10). Median B-line score was 4 (IQR 2–9). Median IMV duration was 92.5 h (IQR 54–132). In mixed-effects linear models adjusting for patient-level predictors (age, PIM3 score), there was a significant association between SF ratio and BLS (p = 0.004), but no significant association between CFB and BLS (p = 0.6) or oedema.
Conclusion
This study describes the use of bedside POCUS assessment to serially assess fluid status in ventilated children. B-line scores correlated with SF ratio, although not with measured fluid balance or oedema. Larger studies are needed to definitively establish clinical utility in this setting.
Excessive intravenous fluid administration can prolong invasive mechanical ventilation (IMV) in critically ill children. In ventilated adults, lung point-of-care ultrasound (POCUS) is increasingly used to assess fluid status. We aimed to assess the correlation between B-lines on daily lung POCUS in ventilated children, contemporaneous oxygenation markers and cumulative fluid balance.
Methods
This prospective single-centre observational cohort study was conducted between March 2023 and May 2024. Doctors and physiotherapists utilised POCUS to measure B-line scores (BLS) across 8 zones in children expected to remain ventilated beyond 24 h. Daily scans were conducted until ventilation liberation or IMV day 7. Contemporaneous oxygen saturation (SpO2):fraction of inspired oxygen (FiO2) (SF) ratio and fluid balance (cumulative fluid balance [CFB] and clinical oedema) were measured. Mixed effects linear regression was used to assess the association between daily B-line scores and SF ratio, CFB and oedema.
Results
Thirty seven children were enrolled (78 scans) with median age 18 months (IQR 9–44). The most common admission reason was respiratory (76%, n = 28). Scans took a median of 10 min (IQR 5–10). Median B-line score was 4 (IQR 2–9). Median IMV duration was 92.5 h (IQR 54–132). In mixed-effects linear models adjusting for patient-level predictors (age, PIM3 score), there was a significant association between SF ratio and BLS (p = 0.004), but no significant association between CFB and BLS (p = 0.6) or oedema.
Conclusion
This study describes the use of bedside POCUS assessment to serially assess fluid status in ventilated children. B-line scores correlated with SF ratio, although not with measured fluid balance or oedema. Larger studies are needed to definitively establish clinical utility in this setting.
Date Issued
2025-07-17
Date Acceptance
2025-06-24
Citation
Intensive Care Medicine – Paediatric and Neonatal, 2025, 3
ISSN
2731-944X
Publisher
Springer Science and Business Media LLC
Journal / Book Title
Intensive Care Medicine – Paediatric and Neonatal
Volume
3
Copyright Statement
© The Author(s) 2025. Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
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Publication Status
Published
Article Number
23
Date Publish Online
2025-07-17