High-flow nasal cannula (HFNC) therapy is routinely used in the treatment of infants with bronchiolitis. This study sought to identify markers associated with failure of HFNC therapy that serve as warnings for early staging of other ventilatory support products. A retrospective study of infants with a diagnosis of bronchiolitis, receiving HFNC and admitted to the pediatric intensive care unit from January 2016 to June 2017, was conducted. The subjects were divided into two study groups according to the success or failure of HFNC therapy. Risk factors were assessed using the following variables: age, time between hospital admission and start of HFNC, equipment model, and the need for a nasogastric tube. Eighty-one infants were studied, and 18 (21.7%) of them exhibited therapy failure. The results of the logistic models showed that the chances of failure for patients requiring a nasogastric tube during HFNC use were more likely than those for patients with oral nutrition (OR = 8.17; 95% CI 2.30–28.99; p = 0.001). The HFNC failure was not associated with the device used (OR = 1.56; 95% CI 0.54–4.52; p = 0.41), time between hospital admission and HFNC installation (OR = 1.01; 95% CI 0.98–1.03; p = 0.73), or age (OR = 0.98; 95% CI 0.82–1.17; p = 0.82). Among late outcomes evaluated, the patients with therapy failure had longer total durations of O2 use (p < 0.001) and longer hospital stays (p < 0.001). The need to use a nasogastric tube during HFNC use was associated with HFNC therapy failure and can be considered as a marker of severity in children with bronchiolitis.

Objective: To evaluate the evolution of clinical outcomes in children with bronchiolitis who used a high-flow nasal cannula, and to determine after long of non-clinical improvement the therapy should be discontinued, and treatment should be escalated to other forms of ventilatory support. Methods: An observational retrospective study of infants with bronchiolitis who used a highflow nasal cannula. Patients were divided into two study groups according to success or failure of high-flow nasal cannula therapy, namely the Success Group and the Failure Group. The main demographics and clinical variables were assessed 30 minutes and 6 hours after initiating therapy until removal of the high-flow nasal cannula. Results: A total of 83 children were studied and 18 children (21.7%) failed therapy. Among subjects with successful therapy, a significant decrease in respiratory rate (p<0.001), and a significant increase in peripheral oxygen saturation (p<0.001) were observed within 30 minutes. The Success Group was significantly different from the Failure Group after 6 hours, for both respiratory rate (p<0.01) and peripheral oxygen saturation (p<0.01). Conclusion:The absence of clinical sign improvement within 30 minutes and for up to a maximum of 6 hours can be considered as failure of the high-flow nasal cannula therapy. If this time elapses with no improvements, escalating to another type of ventilatory support should be considered.