Efficacy of High-Velocity Nasal Insufflation in the Treatment of Hypercapnic Respiratory Failure: A Systematic Review and Meta-Analysis

High-velocity nasal insufflation (HVNI) is a nasal cannula-based respiratory support modality that may offer an alternative interface to noninvasive positive-pressure ventilation (NPPV).However, randomized evidence specific to HVNI in acute hypercapnic respiratory failure remains limited.We conducted a systematic review and meta-analysis of randomized controlled trials comparing HVNI with NPPV in adults with acute hypercapnic respiratory failure.MEDLINE, EMBASE, CENTRAL, ClinicalTrials.gov,and the WHO International Clinical Trials Registry Platform were searched initially on August 24, 2025, and updated on October 17, 2026.Prespecified primary outcomes were treatment failure, patient-reported discomfort, time to successful liberation from assisted ventilation, length of stay, and health-related quality of life.Random-effects meta-analyses used DerSimonian-Laird estimation with Hartung-Knapp-adjusted confidence intervals.The protocol was prospectively registered on the Open Science Framework (OSF; by3je).Four RCTs involving 190 participants were included.HVNI did not show a clear difference in treatment failure compared with NPPV (RR 0.85, 95% CI 0.30-2.45;very low-certainty evidence).Hospital length of stay also showed no clear difference (MD -1.17 days, 95% CI -2.38 to 0.03), and the estimate for ICU length of stay was highly imprecise (MD -0.95 days, 95% CI -6.04 to 4.15).Patient discomfort was reported by one trial and favored HVNI (MD -23.12 points, 95% CI -38.36 to -7.88).No trial reported time to successful liberation from assisted ventilation.Interpretation was limited by the small number and sample sizes of included trials and differences in outcome definitions across studies.Current evidence is insufficient to determine whether HVNI provides clinically comparable outcomes to NPPV in acute hypercapnic respiratory failure.Additional adequately powered randomized trials are required.