High-flow oxygen nasal cannula for treating acute bronchiolitis in infants: A systematic review and meta-analysis

Oxygen therapy through a high-flow nasal cannula is thought to improve the work of breathing and the comfort of patients with acute bronchiolitis. It is widely used in hospital wards and critical care of pediatric patients. However, there is uncertainty on the magnitude of the effect on critical and important outcomes in these patients.

The objective of this review is to evaluate the available evidence on the use of oxygen administered through high-flow cannula versus low-flow oxygen for the treatment of acute bronchiolitis in children under two years of age.

We carried out a systematic review and a meta-analysis following the PRISMA standards for reporting. The search was carried out in electronic databases by two researchers independently. The evidence was summarized using the GRADE methodology.

Six randomized and non-randomized clinical trials were included, including 1867 individuals younger than 24 months of age with acute bronchiolitis in pediatric emergency, hospitalization, and intensive care services. Mortality was not reported in the included studies. Treatment failure occurred in 108/933 in the high flow group and 233/934 in the low flow group (relative risk: 0.46; 95% confidence interval: 0.35 to 0.62), which shows 11.7% less treatment failure (95% confidence interval between 7.9% and 14.5% less) in the high flow group with a number needed to treat of 7.5 (95% confidence interval 6 to 10) with moderate certainty in the evidence.

The use of humidified and heated oxygen with high flow compared to oxygen at low flow is probably associated with decreased treatment failure in children younger than two years with acute bronchiolitis. There is uncertainty about the effect on hospitalization days and clinical progression.