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

**Authors:** Takero Arai, Ryosuke Osawa, Takashi Asai

PMC · DOI: 10.1186/s40981-026-00850-y · JA Clinical Reports · 2026-02-06

## TL;DR

A patient with an unexpected difficult airway was successfully intubated using high-flow nasal oxygenation and a flexible bronchoscope after initial attempts failed.

## Contribution

Demonstrates the usefulness of high-flow nasal oxygenation in managing unexpected difficult airways during awake fiberoptic intubation.

## Key findings

- Awakening the patient and using high-flow nasal oxygenation enabled successful intubation after failed attempts under anesthesia.
- High-flow nasal oxygenation provided a clear view of the glottis and prevented hypoxia during the procedure.
- Flexible bronchoscopy was effective for intubation in a patient with an unexpected difficult airway.

## Abstract

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.

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.

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.

## Full-text entities

- **Diseases:** hypoxia (MESH:D000860), airway obstruction (MESH:D000402), laryngeal edema (MESH:D007819), edema (MESH:D004487), neuromuscular blockade (MESH:D020879), sleep apnea syndrome (MESH:D012891), ovarian malignancy (MESH:D010051), lymph node metastasis (MESH:D008207), deformities (MESH:D009140)
- **Chemicals:** remifentanil (MESH:D000077208), propofol (MESH:D015742), Fentanyl (MESH:D005283), epinephrine (MESH:D004837), oxygen (MESH:D010100), povidone-iodine (MESH:D011206), Sevoflurane (MESH:D000077149), Sugammadex (MESH:D000077122), carbon dioxide (MESH:D002245), dexmedetomidine (MESH:D020927), rocuronium (MESH:D000077123), lidocaine (MESH:D008012), HFNO (-)
- **Species:** Homo sapiens (human, species) [taxon 9606]

## Full text

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## Figures

3 figures with captions in the complete paper: https://tomesphere.com/paper/PMC12972484/full.md

## References

1 references — full list in the complete paper: https://tomesphere.com/paper/PMC12972484/full.md

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Source: https://tomesphere.com/paper/PMC12972484