3.2-Secondary outcome measures
Our results showed that HR, RR, and CRS significantly decreased over time relative to the baseline values within both therapy groups. In the comparison of groups, the mean difference (MD) in the reduction of HR and RR were the greatest at 4 h (MD −19.75 [95% CI, −28.57 to −10.92] and MD −10.61 [95% CI, −14.10 to −7.12], respectively; both P < .001; Table 2; Supplement Table 3; p10-12). The decrease in CRS relative to baseline over time was significantly higher in children treated with HFNCO than those treated with LFO (Table 2; Supplement Table 4; p13,14). The longitudinal analyses for HR, RR, and CRS were given in Supplement Table 5,6; p15-20.
While we found a shorter duration of oxygen therapy in children who received HFNCO (19.0 h [4.0-30.0]; P = .009), there was no significant difference in LOS between the groups (HFNCO; 5.0 d [4.0-7.0]; P = .22; Table 2]. The proportion of treatment failure was present in one patient on HFNCO and ten patients on LFO ​(3% vs. 21%; P = 0.02; Supplement Table 7; p21,22). First, HFNCO was performed on all ten patients. Two patients were transferred to the ICU after further deterioration. Eight patients had a clinical improvement. We did not observe severe AEs, such as pneumothorax, pressure injuries, or child death. Transient bradycardia was seen in both groups (three in HFNCO vs. one in LFO). Epistaxis was found in two patients who received HFNCO therapy (Table 2).