To explore clinical effects of heated humidified high flow nasal cannula (HHHFNC) and nasal continuous positive airway pressure (NCPAP) in initial respiratory support to neonates with mild neonatal respiratory distress syndrome (NRDS).

A total of 73 cases of neonates with mild NRDS in neonatal intensive care unit (NICU) of Xuzhou Central Hospital from June 2017 to November 2018 were selected as research subjects. According to random digits table method, they were divided into HHHFNC group (n=38) and NCPAP group (n=35), and they received HHHFNC and NCPAP non-invasive ventilation mode, respectively. The arterial blood gas analysis indexes, such as pH value, arterial partial pressure of carbon dioxide (PaCO₂) and arterial partial pressure of oxygen (PaO₂) before and after initial respiratory support were observed and compared by independent-samples t test between two groups or by pairwise t test within each group. Duration of non-invasive mechanical ventilation, rates of invasive mechanical ventilation treatment and non-invasive mechanical ventilation-related complications of two groups were compared by independent-samples t test or chi-square test. The study was approved by the Medical Ethics Committee of Xuzhou Central Hospital (Approval No. XZXY-LJ-20161122-010) and the informed clinical research consents were signed by the parents of NRDS children. There were no significant differences in the general clinical data between two groups, such as gender composition ratio, gestational age at birth, birth weight, age at enrollment, glucocorticoid utilization rate from 24 h before birth to 7 d after childbirth of pregnant mother, and treatment rate of pulmonary surfactant (PS) during HHHFNC or NCPAP treatment (P>0.05).

①The arterial blood gas analysis indexes pH value and PaO₂ at 1 h and 24 h after initial respiratory support in HHHFNC group were obviously higher than those before treatment, while PaCO₂ at 24 h after initial respiratory support was obviously lower than that before treatment, and all the differences were statistically significant (pH value comparison: t=2.090, 2.945, P=0.040, 0.004; PaO₂ comparison: t=8.250, 7.730, both P<0.001; PaCO₂ comparison: t=9.677, P<0.001). The pH value and PaO₂ at 1 h and 24 h after initial respiratory support in NCPAP group were obviously higher than those before treatment, while PaCO₂ at 1 h and 24 h after initial respiratory support were obviously lower than that before treatment, and all the differences were statistically significant (pH value comparison: t=2.020, 3.632, P=0.047, 0.001; PaO₂ comparison: t=10.380, 10.797, both P<0.001; PaCO₂ comparison: t=2.666, 10.627, P=0.010, <0.001). There were no statistical differences in pH value, PaCO₂ and PaO₂ at 1 h and 24 h after initial respiratory support between two groups (P>0.05). ②There were no statistically significant differences between two groups in duration of non-invasive ventilation and rate of transferring to invasive mechanical ventilation treatment (P>0.05). The incidence of nasal injury in HHHFNC group was 0, which was significantly lower than that 17.1% (6/35) of NCPAP group, and the difference was statistically different (χ²=5.007, P=0.025).

HHHFNC is equally effective compared with NCPAP in initial respiratory support for mild NRDS and the incidence of nasal injury is significantly lower than that of NCPAP. Because the sample size in this study is relatively small, and stratified analysis based on the gestational age and birth weight of NRDS children has not been conducted, the clinical effect of HHHFNC and NCPAP in initial respiratory support for NRDS still needs multi-center, large-sample, randomized controlled trials for further research and confirmation.