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

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.