Unexpected difficult airway management and usefulness of high-flow nasal oxygenation for awake fiberoptic tracheal intubation: a case report.

BACKGROUND: Unexpected difficult airway management, although rare, may occur after induction of anesthesia. In such cases, appropriate airway management is required to prevent life-threatening hypoxia. CASE PRESENTATION: In a 44-year-old woman without predicted difficult airway, after induction of general anesthesia, repeated attempts at tracheal intubation using videolaryngoscopes had failed, and ventilation using both a facemask and a supraglottic airway became difficult; the patient was awakened and the surgery cancelled. One week later, awake nasotracheal intubation using a flexible bronchoscope was attempted under high-flow nasal oxygenation. A clear view of the glottis was obtained by bronchoscopy and the trachea was intubated successfully without hypoxia. CONCLUSIONS: In patients with unexpected difficult airway management, appropriate airway management (including awakening the patient) is required to prevent life-threatening hypoxia. High-flow nasal oxygenation would be useful for awake fiberoptic intubation, by providing a clear view of the glottis and by preventing hypoxia.