Predictive factors for high-flow nasal cannula failure in patients with acute viral bronchiolitis admitted to the pediatric intensive care unit.

Abstract

Objective: To identify predictive factors for failure in the installation of high-flow nasal cannulas in children diagnosed with acute viral bronchiolitis under 24 months of age admitted to the pediatric intensive care unit.

Methods: This work was a retrospective single-center cohort study conducted from March 2018 to July 2023 involving infants under 24 months of age who were diagnosed with acute viral bronchiolitis and who received high-flow nasal cannulas upon admission to the pediatric intensive care unit. Patients were categorized into two groups, the Success Group and Failure Group, on the basis of high-flow nasal cannula therapy efficacy. The primary outcome was treatment failure, which was defined as the transition to invasive or noninvasive ventilation. The analyzed variables included age, sex, weight, high-flow nasal cannula parameters, vital signs, risk factors, comorbidities, and imaging. Acute viral bronchiolitis severity was assessed using the Wood-Downes Scale, and functional status was assessed via the Functional Status Scale, both of which were administered by trained physiotherapists.

Results: In total, 162 infants with acute viral bronchiolitis used high-flow nasal cannulas, with 17.28% experiencing treatment failure. The significant differences between the Failure and Success Groups included age (p = 0.001), weight (p = 0.002), bronchiolitis severity (p = 0.004), initial high-flow nasal cannula flow (p = 0.001), and duration of use (p = 0.000). The cutoff values for initial flow (≤ 12L/min), weight (≤ 5kg), and Wood-Downes score (≥ 9 points) were determined from the ROC curves. Initial flow ≤ 12L/min was the most predictive for failure (AUC = 0.71; 95%CI: 0.61 - 0.84; p = 0.001). Multivariate analysis indicated that weight was a protective factor (RR = 0.87; 95%CI: 0.78 - 0.98), duration of use reduced the risk of failure (RR = 0.49; 95%CI: 0.38 - 0.64; p = 0.000), and Wood-Downes score was not significant (RR = 1.04; 95%CI: 0.95 - 1.14; p = 0.427). Weight explained 84.7% of the variation in initial flow.

Conclusion: Risk factors for high-flow nasal cannula therapy failure in bronchiolitis patients include younger age, consequently lower weight, and a lower initial flow rate.