Risk factors for treatment failure of heated humidified high-flow nasal cannula as an initial respiratory support in newborn infants with respiratory distress

Background: Humidified high-flow nasal cannula (HHFNC) has gained popularity because it is easier to use, more comfortable for babies, and advantageous for mother-infant bonding. HHFNC is not inferior to other non-invasive ventilators for preventing adverse outcomes, but more studies are needed to ensure the safe use of HHFNC as an initial respiratory support for newborns. The aim of this study was to investigate risk factors for treatment failure of HHFNC as an initial respiratory support in newborns with respiratory distress after birth. Methods: We included 97 newborns who required non-invasive respiratory support within 24 h after birth. The success group included 68 infants who were successfully managed only on HHFNC, and 29 infants were the failure group who required other respiratory support because of respiratory acidosis, hypoxia, or apnea. Results: Compared with the success group, the failure group had lower GA, a higher rate of antenatal steroid use, prolonged rupture of membrane, lower pH, higher pCO₂ on blood-gas analysis after HHFNC application and higher incidence of respiratory distress syndrome of newborn (RDS). After adjusting for GA, higher FiO₂ settings during acidosis, hypercarbia after the application of HHFNC shown on blood-gas analysis and the presence of RDS remained significant. The rate of treatment failure was 16.2% for ≥36 weeks, 19.3% for ≥34 weeks, and 22.1% for ≥33 weeks. Conclusion: Treatment failure of HHFNC should be considered a risk for newborns of less than 34 weeks and infants with respiratory distress from RDS. Higher FiO₂ settings during HHFNC, and acidosis and hypercarbia after the application of HHFNC shown on blood-gas analysis may help identify high-risk newborns for other non-invasive ventilators or intubation.