High-flow nasal oxygen (HFNO) is a potentially life-saving adjunct in the emergency management of the obstructed airway. HFNO has multiple beneficial applications in critical care and respiratory support, but its use in emergency-obstructed airway management has not been defined. This case report describes spontaneous respiration using intravenous anesthesia and high-flow nasal oxygen to successfully manage acute adult epiglottitis with rapidly progressing airway obstruction. Oxygenation, carbon dioxide levels, and airway patency were maintained, which facilitated endotracheal intubation while the patient was spontaneously breathing during general anesthesia. The application of HFNO can be extended to emergency airway obstruction.