FRCA Notes

Airway injury

This topic is yet to be the subject of a CRQ/SAQ, though the relatively recent BJA Education article on laryngeal complications does seem a prime target.

Exams aside, it's important to understand the potential trauma one can cause from an activity performed daily at work.

NB this page does not cover tracheostomy-associated complications, which can be found on the tracheostomy page.

Resources

  • Instrumentation of the airway can lead to damage of the airway and surrounding structures
  • Indeed, 85% of airway injuries occur following short-term tracheal intubation
  • There is a higher risk with repeated intubation attempts, during difficult intubation or during periods of prolonged intubation
  • However, 80% of airway injuries follow routine, not-difficult tracheal intubation
  • Injuries to the oesophagus account for 18% of airway injuries

Risk factors

  • Female gender
  • Age >60yrs
  • Difficult intubation inc. use of bougies or other thin introducers

Clinical features

  • Sore throat
  • Neck/cervical pain
  • Cough
  • Fever (a symptom less likely in tracheal rupture)
  • Dysphagia (also less likely in tracheal rupture)
  • Subcutaneous emphysema | pneumomediastinum | pneumothorax

Management

  • The surgical holy trifecta of NBM, IV antibiotics and surgical repair
  • TPN may be necessary

Sequelae

  • Such an occurrence is no bueno and may lead to:
    • Retropharyngeal abscess formation
    • Acute mediastinitis
    • Pneumonia
    • MODS

  • 15% of airway injuries are to the trachea

  • Reportedly ~5% of bougie-assisted intubations result in minor airway trauma
  • As such, bougies and airway exchange catheters should be inserted to a maximum of 26cm to avoid tracheobronchial tree damage

  • At the more severe end of the spectrum is tracheal rupture
  • Typically it occurs following difficult intubation or repeated airway trauma, but can follow uneventful intubations owing to incorrect ETT sizing or cuff over-inflation

Clinical features

  • Subcutaneous emphysema | pneumomediastinum | pneumothorax
  • Dyspnoea
  • Dysphonia
  • Cough
  • Haemoptysis

Management

  • I&V with cuff inflation distal to the rupture
  • Tracheal aspiration
  • Pleural drain
  • Empirical antibiotics
  • ± Surgical correction

  • Localised ischaemia of the tracheal mucosa predisposes to granulation tissue formation and consequent stenosis of the tracheal lumen
  • With a reported incidence of 4.9/1,000,000/yr, intubation-associated stenosis accounts for 80% of all acquired tracheal stenosis
  • The incidence increases with prolonged periods of intubation
  • Use of high-volume, low-pressure cuffs and maintaining cuff pressure <30cmH2O reduces the incidence
  • May be amenable to balloon dilatation with early recognition and treatment (<3 months)

  • Laryngeal injury (~33% airway injuries) typically presents with hoarseness and dysphonia immediately after extubation
  • The majority of injuries are minor, transient and result from mild erythema/oedema

Injuries

  • Vocal cord haematoma
  • Vocal cord palsy/paresis
  • Vocalis muscle laceration

  • Laryngeal stenosis
  • Laryngeal oedema

  • Mucosal laceration
  • Mucosal thickening
  • Ulcer or granuloma formation

Risk factors


Patient factors Intubation factors
Age >50yrs (3x ↑ risk vocal cord paralysis) Larger ETT size
Diabetes mellitus or HTN (2x ↑ risk) Use of bougie/airway catheter
Smoking Intubating without NMBA
Female gender Prolonged intubation (15x risk of vocal cord paralysis if I&V for >6hrs)
GORD Critical illness
Obesity
Malnutrition + hepatic or renal failure

Management

  • Treat oedema with steroids
  • If GORD contributing, add PPI
  • Reduce secretion burden: ventilator care bundle, supra- and sub-glottic suctioning or anti-cholinergic pharmacotherapy e.g. atropine, glycopyrrolate, hyoscine
  • Restore trans-laryngeal flow e.g. cuff deflation, speaking valves, above-cuff vocalisation
  • SLT input
  • Pharyngeal electrical stimulation
  • Surgical intervention e.g. vocal cord medialisation, vocal fold injection, laryngeal framework surgery or arytenoid adduction procedures

  • 19% of airway injuries occur in the pharynx, including the uvula
  • Uvular necrosis is a rare occurrence following mechanical trauma during intubation or suctioning

Clinical features

  • Sensation of a foreign body
  • Sore throat
  • Odynophagia
  • Coughing
  • ± airway obstruction if severe

Management

  • Usually conservative e.g. steroids, antibiotics, topical adrenaline, anti-histamines

  • Arises from direct trauma to the cricoarytenoid joint during intubation
  • Symptoms include persistent dysphonia, dysphagia, sore throat and stridor
  • Requires early operative correction to prevent articular adhesions or ankylosis


Injury Comments
Soft-tissue facial injuries e.g. abrasions, ulcers Face masks esp. CPAP/NIV
TMJ Injury Accounts for 10% of airway injuries
Nasal injury Accounts for 5% of airway injuries
Epistaxis In up to 50% of nasal intubations
Mental nerve or mandibular nerve neuropraxia Transient, due to excessive force from anaesthetic hands holding airways
Lingual nerve, hypoglossal nerve or recurrent laryngeal nerve neuropraxia Transient, due to supra-glottic devices esp. with over-inflation of LMA cuffs