Objective To determine whether electrical activity of the diaphragm (Edi) changes with weaning nasal high-flow (HF) therapy in preterm infants according to a standardised protocol.
Design Prospective observational cohort study.
Setting Neonatal intensive care unit.
Patients Preterm infants born at <32 weeks gestation, receiving nasal HF as part of routine clinical care.
Interventions Infants recruited to the study had their HF weaned according to set clinical criteria. Edi was measured using a modified gastric feeding tube serially from baseline (pre-wean) to 24-hours post-wean.
Main outcome measures Change in Edi from baseline was measured at four time points up to 24 hours after weaning. Minimum Edi during expiration, maximum Edi during inspiration and amplitude of the Edi signal (Edidelta) were measured. Clinical parameters (heart rate, respiratory rate and fraction of inspired oxygen) were also recorded.
Results Forty preterm infants were recruited at a mean corrected gestational age of 31.6 (±2.7) weeks. Data from 156 weaning steps were analysed, 91% of which were successful. Edi did not change significantly from baseline during flow reduction steps, but a significant increase in diaphragm activity was observed when discontinuing HF (median increase in Edidelta immediately post-discontinuation 1.7 µV (95% CI: 0.6 to 3.0)) and at 24 hours 1.9 µV (95% CI: 0.7 to 3.8)). No significant difference in diaphragm activity was observed between successful and unsuccessful weaning steps.
Conclusions A protocolised approach to weaning has a high probability of success. Edi does not change with reducing HF rate, but significantly increases with discontinuation of HF from 2 L/min.
- Respiratory Medicine
Data availability statement
All data relevant to the study are included in the article or uploaded as supplemental information.
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MB, SH and CO contributed equally.
Contributors RN, ACF, MB, SH and CO'B conceptualised and designed the study. RN collected data. RN, SH, MB and CO'B analysed and interpreted data. RN drafted the initial manuscript. MB, SH, CO'B, ACF and RN reviewed and revised the initial manuscript. RN is guarantor.
Funding This study was funded by Tiny Lives (registered charity 1150178).
Disclaimer The funders had no role in the study design or analysis.
Competing interests RN, ACF, SH, CO'B: None. Not related to this work, MB received investigator-led research grants from Pfizer and Roche Diagnostics; speaker fees paid to Newcastle University from Novartis, Roche Diagnostics and TEVA; travel expenses to educational meetings from Boehringer Ingelheim and Vertex Pharmaceuticals.
Provenance and peer review Not commissioned; externally peer reviewed.
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