Comparison of High-Flow Nasal Cannula versus Continuous Positive Airway Pressure in the Management of Bronchiolitis: A Systematic Review of Randomized Controlled Trials

Abstract

Bronchiolitis is the leading cause of hospitalization in infants. While Continuous Positive Airway Pressure (CPAP) has been the gold standard for non-invasive respiratory support, High-Flow Nasal Cannula (HFNC) therapy has emerged as a popular alternative. However, evidence on their comparative efficacy remains contradictory. This systematic review aimed to compare the efficacy, safety, and practical implications of HFNC versus CPAP for managing moderate to severe bronchiolitis in infants, based on recent randomized controlled trials (RCTs). Following PRISMA guidelines, a systematic search was conducted in PubMed/MEDLINE, Embase, Cochrane CENTRAL, and Web of Science for RCTs published from 2014 to 2024. Studies comparing HFNC and CPAP in infants (1-24 months) with bronchiolitis were included. Primary outcome was treatment failure, defined as escalation of respiratory support. Secondary outcomes included intubation rate, length of stay, and tolerance. Risk of bias was assessed using the Cochrane RoB 2 tool. Five RCTs (n=628) were included. The evidence for the primary outcome was conflicting. Two trials demonstrated superior efficacy for CPAP in preventing treatment failure, particularly in infants ≤6 months old. In contrast, one more recent trial found HFNC superior to bubble CPAP. However, no study found a statistically significant difference in the rate of endotracheal intubation. HFNC was consistently associated with better patient tolerance and comparable safety, with no increase in serious adverse events. Current RCT evidence does not establish clear superiority of one modality. CPAP may be more effective in preventing treatment failure, especially in younger infants, while HFNC offers superior comfort without increasing the risk of intubation. The choice may be guided by patient age, disease severity, and clinical context, with HFNC serving as a well-tolerated first-line option and CPAP as a robust intervention for higher-risk patients or after HFNC failure. Protocol heterogeneity highlights the need for standardized, optimized approaches in future research.