Baseline characteristics of study patients.

Background
High-flow nasal cannula (HFNC) therapy has gained popularity in the pediatric intensive care unit (PICU). However, the nationwide effect of HFNC on mechanical ventilation duration has not been studied.
Methods
We retrospectively analyzed pediatric patients (28 days to 17 years old) admitted to tertiary ICUs for respiratory support from 2012 to 2019 using the Korean National Health Insurance database. Pre-/post-HFNC periods were defined as the 12 months before and after the application of HFNC in any hospital, respectively, allowing a 6-month transition period. Mechanical ventilation duration and ventilator-free days during these two periods were compared using a multivariable regression model.
Results
Using data from 46 hospitals, 4,705 and 4,864 respective pre-/post-HFNC period patients were evaluated. During the post-HFNC period, 14.8% of patients were treated by HFNC, and 67.1% were treated using invasive mechanical ventilation. In adjusted analysis, mechanical ventilation duration was reduced by 0.99 days (confidence interval [CI]: -1.86, -0.12). The duration was significantly reduced by 17.81 days (CI: -35.46, -0.16) among patients whose ventilation duration was longer than 28 days. In subgroup analysis, mechanical ventilation duration was reduced by 1.49 days (CI: -2.78, -0.19) in the overall surgical group and 6.71 days (CI: -11.71, - 1.71) in the neurologic subgroup. Ventilator-free days were increased only in the overall surgical group, by 0.31 days (CI: 0.01, 0.61).
Conclusions
Application of HFNC to PICU patients could reduce mechanical ventilation duration, especially in patients requiring prolonged mechanical ventilator support or in post-operative patients.