Comparison of high-flow nasal cannula and noninvasive ventilation in COVID-19-related hypoxemic respiratory failure: a retrospective observational study

Abstract

Background
High-flow nasal cannula (HFNC) and noninvasive ventilation (NIV) are widely used noninvasive respiratory support modalities in COVID-19-related hypoxemic respiratory failure. However, comparative data on their effectiveness and safety remain limited.


Methods
We conducted a retrospective observational study involving 50 patients with COVID-19-induced hypoxemic respiratory failure, with 25 patients receiving HFNC and 25 receiving NIV. Baseline characteristics, clinical outcomes, physiological responses, and safety events were analyzed.


Results

Despite the NIV group having more severe baseline illness—including higher APACHE II scores, greater comorbidity burden, and lower initial SpO₂—there were no significant differences between groups in in-hospital mortality (
P
 = 0.248), ICU and hospital length of stay, or need for invasive mechanical ventilation. Although post-therapy respiratory rate and serum lactate levels were lower in the HFNC group, the magnitude of change from baseline did not differ significantly between groups. Safety outcomes, including sedation needs, vasopressor use, acute kidney injury, renal replacement therapy, pneumothorax, and surgical emphysema, were similar between groups.



Conclusion
HFNC and NIV were associated with similar observed clinical and safety outcomes in COVID-19-related hypoxemic respiratory failure, However, interpretation is limited by baseline imbalances between groups, potential confounding by indication, and the relatively small sample size. These findings should be considered hypothesis-generating and warrant validation in larger, well-designed prospective studies.