Abstract
Background: Noninvasive respiratory support with nasal high flow (NHF) as an alternative to continuous positive airway pressure (CPAP) is commonly used in neonates who require supplemental O2 to maintain arterial blood O2 saturation (SpO2). It has been shown that upsizing the high flow nasal cannula (HFNC) interface increases pressure during NHF and the beneficial role of positive airway pressure in respiratory failure is well known.
Objectives: To compare an effect of smaller (S) and larger (L) HFNC on SpO2 in newborns with respiratory failure requiring NHF with supplemental O2 as a standard therapy protocol.
Methods: In a prospective crossover study of 24 neonates with mean gestational age 36.4 ± 1.97 weeks, 2 types of HFNC with NHF 8 L/min were randomly assigned to 2 groups with 3 periods (30 min/period) in the following sequences L-S-L or S-L-S. The fraction of inspired oxygen (FiO2) was set at the start of the first period to maintain SpO2 between 90% and 94%. Apart from SpO2, transcutaneous CO2 and O2 as well as respiratory frequency and effort using inductance plethysmography were measured. Each period was assessed by a fixed effects analysis of variances.
Results: NHF therapy via the L interface resulted in higher SpO2 than via the S interface (92.2% vs. 91.3%) with a difference of 0.90 (CI 0.271 - 1.529), p = 0.006, at the same FiO2. Individual actual and mean LOESS profile plots demonstrated the difference in SpO2 throughout all 3 study periods. The secondary outcomes did not change significantly.
Conclusion: Enlarged prongs in the HFNC interface led to higher SpO2, indicating an improved gas exchange that can be related to increased positive airway pressure.
Footnotes
Cite this article as Eur Respir J 2022; 60: Suppl. 66, 4456.
This article was presented at the 2022 ERS International Congress, in session “-”.
This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).
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