Post-Extubation Laryngeal Oedema

Post-extubation laryngeal oedema is swelling of the supraglottic, glottic or subglottic mucosa after intubation, leading to stridor or failure of extubation. It is a common pathological cause of post-extubation stridor.

Epidemiology. Endoscopic laryngeal oedema occurs in most patients intubated over 24 hours, but only 5% to 20% have symptomatic stridor. Reintubation follows in 1% to 15%.

Risk factors. Intubation longer than 36 to 48 hours, large tube, traumatic or difficult intubation, high cuff pressure, repeated intubation, female sex, fluid overload, head and neck surgery, sepsis, steroids free ventilation and absent cuff leak.

Pathophysiology.

Pressure ischaemia and abrasion damage mucosa and cause capillary leak, venous congestion and lymphatic obstruction. The loose submucosa of the supraglottis and subglottis swells quickly.

Stridor within minutes to 24 hours of extubation, hoarse voice, cough, dyspnoea, sore throat, dysphagia and respiratory distress.

Red flags.

• Biphasic stridor with exhaustion.
• Cyanosis or silent chest.
• Rapid progression over 30 minutes.

Cuff leak test before extubation: leak under 110 mL, or under 24% of delivered tidal volume, predicts oedema. Flexible nasendoscopy confirms oedema, ulceration and cord mobility. CT or ultrasound for neck pathology.

Differential diagnosis.

• Vocal cord paralysis.
• Arytenoid dislocation.
• Laryngospasm.
• Neck haematoma.
• Tracheal injury or stenosis.
• Anaphylaxis.

Sit the patient up, give humidified oxygen, and start the following. Reintubate early if exhaustion or hypoxaemia develops.

• Adrenaline (nebulised): 5 mg (5 mL of 1 mg/mL) in adults; repeat after 20 minutes; maximum 3 doses in the first hour; monitor heart rate and rhythm; observe 2 to 4 hours for rebound; use caution in ischaemic heart disease.
• Dexamethasone: 8 mg IV every 8 hours for 24 hours (children 0.5 mg/kg, maximum 10 mg); maximum 24 mg daily in adults; monitor glucose and blood pressure.
• Methylprednisolone: 40 mg IV every 6 hours for 24 hours before planned extubation in high risk patients (started 12 to 24 hours before); maximum 160 mg daily for this use; monitor glucose; avoid in uncontrolled infection.

Use awake fibreoptic reintubation with a smaller tube if possible, keep patient sitting and have surgical airway equipment ready.

Prevention. Cuff leak test, steroids for high risk patients, reduce fluid excess, minimise tube size and cuff pressure (20 to 30 cmH2O), and avoid unnecessary tube movement.

Monitoring. Stridor, saturation, voice and swallow for at least 24 hours after extubation.

Referral and escalation. ENT and critical care for stridor with distress. Laryngoscopy review for hoarseness lasting over 2 weeks.