Comparison of heated humidified high-flow nasal cannula flow rates (1-L·kg·min-1 vs 2-L·kg·min -1 ) in the management of acute bronchiolitis

Abstract

Objective: We aimed to compare the heated humidified high-flow nasal cannula (HHHFNC) flow rate of 1-L·kg·min^-1 (1 L) with 2-L·kg·min ^-1 (2 L) in patients with severe bronchiolitis presenting to the pediatric emergency department.

Study design: We performed a study in which all patients were allocated to receive these two flow rates. The primary outcome was admitted as treatment failure, which was defined as a clinical escalation in respiratory status. Secondary outcomes covered a decrease of respiratory rate (RR), heart rate (HR), the clinical respiratory score (CRS), rise of peripheral capillary oxygen saturation (SpO₂ ), and rates of weaning, intubation, and intensive care unit (ICU) admission.

Results: One hundred and sixty-eight cases (88 received the 1-L flow rate and 80, the 2-L flow rate) were included in the analyses. Treatment failure was 11.4% (10 of 88) in the 1-L group, and 10% (8 of 80) in the 2-L group (P = .775). Significant variation in the intubation rate or the ICU admission rate was not determined. At the 2nd hour, the rate of weaning (53.4% vs 35%; P = .017), the falling down of the CRS (-2.1 vs -1.5; P < .001), RR (-15.2 vs -11.8; P < .001), and HR (- 24.8 vs - 21.2; P < .001), and the increase of SpO ₂ (4.8 vs 3.6; P < .001) were significantly more evident in the 1-L group.

Conclusion: HHHFNC with the 1-L·kg·min^-1 flow rate, which provides a more frequent earlier effect, reached therapy success as high as the 2-L·kg·min ^-1 flow rate in patients with severe acute bronchiolitis.

Keywords: bronchiolitis; emergency deparment; flow rate; high flow nasal cannula.