Comparing Efficacy of Three Strategies for Weaning of High Flow Nasal Cannula in Critically Ill Patients with Acute Hypoxemic Respiratory Failure: Exploratory Randomized Trial; An Interim Analysis

INTRODUCTION: High Flow Nasal Cannula (HFNC) therapy is increasingly used in managing Acute Hypoxemic Respiratory Failure (AHRF) due to its ability to deliver high oxygen flow with added benefits of heated humidification. However, standardized protocols for weaning from HFNC remain underexplored, creating variability in clinical outcomes. This interim analysis assesses the efficacy of three HFNC weaning strategies to optimize patient outcomes.(1,2) OBJECTIVES: To evaluate and compare the success rates, weaning duration, and patient comfort among three weaning strategies: 1. Flow reduction first. 2. FiO(2) reduction first. 3. Simultaneous reduction of both flow and FiO(2). MATERIALS AND METHODS: A prospective randomized controlled trial was initiated at AIIMS, Rishikesh (August 2023–September 2024). Of the targeted 100 patients, interim analysis includes 65 participants randomized into three groups: Group A Flow reduction first. Group B FiO(2) reduction first. Group C Simultaneous reduction of flow and FiO(2). Randomization was done using a computer-generated system, and allocation was concealed via opaque envelopes. HFNC weaning success was defined as maintaining clinical stability on conventional oxygen therapy for 48 hours post-weaning. Comfort was assessed using a validated Visual Numerical Scale (VNS), and adverse events were recorded. Data on weaning time, patient comfort, adverse events, and ICU length of stay were collected. Statistical comparisons were performed using chi-square and Kruskal Wallis test, with significance set at p < 0.05. RESULTS: The interim analysis included 65 patients (66.2% male; mean age 46.9 ± 15.8 years). The overall weaning success rate was 87.7%. Group C exhibited the highest success rate (94.7%), followed by Group A (91.3%) and Group B (78.3%) (p = 0.218). The time to wean off HFNC was comparable across all groups (p = 0.67). Patient comfort scores were highest in Group C. Adverse events, such as nasal irritation and dryness along with air leak, were least frequent in Group C. Subgroup analysis indicated consistent results among patients with de novo AHRF and acute-on-chronic respiratory failure.(3–5) CONCLUSIONS: The interim analysis indicates that simultaneous reduction of flow and FiO(2) may be the most effective HFNC weaning strategy, yielding higher success rates, superior comfort, and lower adverse event rates. The statistically significant differences in comfort and complications underscore the potential clinical value of adopting this approach as a standardized weaning protocol. These findings are instrumental in guiding resource optimization in ICU settings and improving patient care. Completion of the study cohort will provide further validation and generalizability of these results.