High-flow oxygen therapy delivered through tracheostomy: A scoping review of physiology, clinical applications, safety, and pediatric evidence gaps

Introduction High-flow oxygen therapy delivered through tracheostomy (HFTO) is used for oxygenation, heated humidification, secretion management, ventilator weaning, and decannulation. Its effects depend on flow, tracheostomy interface, cuff status, and the expiratory pathway, while pediatric evidence is poorly defined. Methods We conducted a PRISMA-ScR-guided scoping review of adult and pediatric HFTO evidence. MEDLINE/PubMed, Embase, Scopus, Web of Science, and CINAHL were searched from inception through June 30, 2026 without age or database-level language restrictions. Adult evidence was included as a comparator to define pediatric evidence gaps. Results Of 487 records identified, 319 remained after deduplication; 134 underwent full-text/full-record assessment, 99 were excluded, and 35 sources were included (32 completed and 3 ongoing trial/protocol records). Adult flows were commonly 40-60 L/min, with experimental settings of 10-80 L/min; the pediatric simulation used 5-30 L/min. Several adult studies reported improved oxygenation, whereas others found no change; effects on work of breathing, carbon dioxide clearance, airway pressure, and lung volume were variable. Safety reporting was inconsistent. Direct pediatric evidence was limited to one infant/toddler aerosol-delivery simulation. Discussion HFTO is an interface-dependent respiratory therapy rather than a tracheostomy equivalent of nasal high-flow therapy. Cuff status, speaking-valve configuration, expiratory patency, flow, humidification, and treatment purpose should be reported explicitly. Adult feasibility cannot be assumed to establish pediatric effectiveness or safety. Conclusion HFTO is feasible but incompletely defined. Standardized reporting of flow, interface/cuff configuration, humidification, monitoring, adverse events, secretion outcomes, and pediatric-specific clinical outcomes is needed.