Abstract
Objective Nasal continuous positive airway pressure (nCPAP) and nasal high-flow therapy (nHFT)
are the most common forms of noninvasive respiratory support in preterm infants. We
conducted this study to compare effects of nCPAP and nHFT on diaphragmatic dimensions
as assessed by bedside ultrasonography in preterm infants.
Study Design A prospective, randomized crossover study comprised 24 preterm infants. Group 1 (n = 12): started on nCPAP for 60 minutes and then switched to nHFT for 60 minutes.
Group 2 (n = 12): started on nHFT for 60 minutes then switched to nCPAP for 60 minutes. Ultrasonographic
assessment of diaphragmatic dimensions was performed at the end of each epoch.
Results There were no statistically significant differences in diaphragmatic dimensions at
the end of each epoch of nCPAP or nHFT. The diaphragm thickening fraction (DTF) was
not significantly different with either nCPAP or nHFT [23.4 (13.7–28.0) versus 23.4
(11.2–31.6), p = 0.57]. No significant differences were found regarding heart rate, respiratory
rate, Silverman–Anderson scores, and SpO2 on nCPAP and nHFT. All infants enrolled tolerated the crossover maneuver.
Conclusion Stable preterm infants (30.3 ± 2.2 weeks' gestation) with mild respiratory dysfunction
show comparable effects on diaphragm thickness and excursion during relatively brief
periods of support on nCPAP or nHFT.
Clinical Trial Registration Registry name: Clinical Trials.gov. Registration number: NCT02421328. Web link to
study on registry: https://clinicaltrials.gov/ct2/show/NCT02421328.
Keywords
CPAP - nHFT - preterm - diaphragm - ultrasound