Protocolized Weaning of High-Flow Nasal Cannula in Adult Patients

High-flow nasal cannula (HFNC) is a type of oxygen therapy commonly used in adults with breathing problems. While HFNC can help patients avoid breathing tubes and improve oxygen levels, there is no standard method for deciding how and when to reduce and stop this therapy once a patient improves. In many hospitals, these decisions vary from clinician to clinician. This study will compare usual care with a standardized step-by-step plan for reducing HFNC support. Eight hospitals will participate and will switch from usual care to the standardized plan at different time points during the study. The main goal is to determine whether the standardized weaning plan increases the number of patients who can successfully stop HFNC within 5 days. The study will also evaluate how long patients remain on HFNC, whether they need additional breathing support, and how long they stay in the hospital. The results may help develop clearer guidance for safely and efficiently stopping HFNC therapy.

Inclusion Criteria: * Adult patients ≥ 18 years * Receiving HFNC for ≥12 hours * Receiving HFNC to treat acute hypoxemic respiratory failure, defined as requirement of FIO2 ≥ 0.5 to maintain SpO2 at 90-97% and Evidence of increased work of breathing at initiation (e.g., tachypnea with respiratory rate \> 20-25/min, or accessory muscle use), including: * Patients using HFNC to avoid intubation * Post-extubated patients who develop acute hypoxemic respiratory failure, regardless of respiratory support device prior to HFNC use. * The bedside clinical team determines that HFNC weaning is clinically appropriate * Demonstrates clinical stability, defined as: * Respiratory rate ≤ 25 breaths per minute without use of accessory respiratory muscles * SpO₂ \> 90% on HFNC * HFNC FiO₂ ≤ 0.80 Exclusion Criteria: * • Planned procedures requiring intubation * Hypercapnia (PaCO2 ≥ 45 mmHg) * Receiving extracorporeal membrane oxygenation (ECMO) * Receiving continuous aerosol therapy via HFNC (e.g., inhaled nitric oxide \[iNO\], epoprostenol, or continuous albuterol) * Receiving chronic home use of HFNC, CPAP, or noninvasive ventilation therapy to treat chronic respiratory failure * Receiving HFNC as preventative post-extubation therapy, defined as HFNC use immediately after extubation for less than 48 hr in the absence of clinical signs of respiratory failure.