Abstract

Background: Type II respiratory failure remains a significant cause of morbidity and mortality in critically ill patients. While non-invasive ventilation (NIV) is the established standard of care, high-flow nasal cannula (HFNC) has emerged as a promising alternative respiratory support modality.
Objective: To compare the clinical efficacy, safety, and patient tolerance of HFNC versus NIV in patients with acute type II respiratory failure.
Methods: This prospective randomized controlled trial was conducted over 18 months in a tertiary care respiratory intensive care unit. Eighty patients with acute type II respiratory failure were randomly allocated to receive either HFNC (n=40) or NIV (n=40). Primary outcome measures included improvement in arterial blood gas parameters (pH, PaCO₂, PaO₂), respiratory rate, heart rate, and treatment failure rates. Secondary outcomes included patient comfort scores, complications, duration of respiratory support, intensive care unit length of stay, and in-hospital mortality.
Results: Both groups demonstrated significant improvement in arterial blood gas parameters at 1, 6, 12, and 24 hours. The NIV group showed faster correction of hypercapnia and respiratory acidosis at 1 hour (mean PaCO₂: 52.3±6.8 vs 58.7±7.2 mmHg, p<0.001). However, by 24 hours, differences in pH and PaCO₂ were not statistically significant between groups. HFNC demonstrated superior patient comfort scores (8.2±1.1 vs 5.6±1.4, p<0.001) and significantly lower rates of skin breakdown (2.5% vs 22.5%, p=0.006). Treatment failure rates were comparable (HFNC: 12.5% vs NIV: 15.0%, p=0.74). No significant differences were observed in ICU length of stay or mortality rates.
Conclusion: HFNC represents an effective and well-tolerated alternative to NIV in managing acute type II respiratory failure, particularly in patients who may not tolerate NIV. While NIV provides faster initial correction of hypercapnia, HFNC offers comparable efficacy with superior comfort and fewer interface-related complications.