HIGH-FLOW NASAL CANNULA VERSUS NON-INVASIVE VENTILATION IN ADULTS WITH ACUTE HYPOXEMIC RESPIRATORY FAILURE AN UPDATED SYSTEMATIC REVIEW AND QUANTITATIVE DESCRIPTIVE SYNTHESIS

High-flow nasal cannula and non-invasive ventilation are widely used to support adults with acute hypoxemic respiratory failure while attempting to avoid invasive ventilation. HFNC offers heated humidified high flow, stable inspired oxygen, washout of nasopharyngeal dead space, and modest positive pressure; NIV provides greater pressure support and positive end-expiratory pressure but can be less tolerated and may risk injurious tidal volumes or delayed intubation. Objective: To evaluate the effectiveness, safety, and implementation implications of the specified noninvasive respiratory-support strategy in adults with acute hypoxemic respiratory failure. Methods: This PRISMA 2020-aligned updated systematic-review draft maps PubMed-indexed and publisher-verified evidence available through 29 August 2026. Comparative trials, evidence syntheses, and relevant Saudi/GCC implementation studies were extracted. Heterogeneous populations, comparators, and outcome definitions precluded a new pooled meta-analysis; published estimates are displayed descriptively. Results: Nine core reports were mapped. Comparative syntheses generally found no clear difference between HFNC and NIV in intubation or mortality, with low-certainty and heterogeneous evidence. In COVID-19 AHRF, pooled intubation was similar (RR 1.01, 95% CI 0.85–1.20), while NIV improved PaO2/FiO2 more. A Saudi cohort found HFNC failure and intubation in 66%, with high SOFA and low ROX associated with failure. Conclusion: HFNC and NIV appear similarly effective for many adults with acute hypoxemic respiratory failure, but confidence is limited and neither strategy is universally superior.