High-Flow Nasal Cannula versus Conventional Oxygen Therapy after Planned Extubation in Post-Neurosurgical Acute Brain Injury: A Propensity Score–Matched Study

This was an observational exposure, not an investigator-assigned intervention. Participants could receive HFNC regardless of their involvement in this study. The decision to use HFNC or conventional oxygen therapy after extubation was made independently by the attending ICU physicians according to routine clinical practice and the patient’s clinical condition. Study enrolment did not determine, restrict, or provide access to HFNC. Procedures: HFNC was initiated immediately after planned extubation when selected by the treating physician. The initial flow rate was 60 L/min, with FiO2 titrated between 30–60% to maintain SpO2 between 95–100%. HFNC was planned to be continued for at least the first 24 hours after extubation. After 24 hours, the flow rate was reduced by 10 L/min every 6 hours as tolerated and discontinued when the patient remained clinically stable. The usual planned duration was 24–48 hours, with clinical outcomes assessed during the first 72 hours after extubation. Adherence assessment: HFNC use, initial settings, duration, weaning, discontinuation, escalation of respiratory support, and reintubation were assessed through prospective review of ICU medical records, bedside monitoring charts, and respiratory therapy/nursing documentation. Who delivered the exposure: HFNC was delivered by ICU physicians and nurses in the Surgical Intensive Care Unit as part of standard post-extubation care.