Airway management in head and neck cancer

Surgical approach (typical head & neck cancer pathways impacting the airway)

• Diagnostic/airway assessment procedures
  • Flexible nasendoscopy in clinic; panendoscopy (laryngoscopy/bronchoscopy/oesophagoscopy) under GA
  • Biopsy of tumour (oral cavity/oropharynx/larynx/hypopharynx) ± laser debulking to improve airway
• Definitive oncological surgery (often shared airway)
  • Transoral surgery (TLM/TORS), partial/total laryngectomy, pharyngectomy; neck dissection
  • Reconstruction: pedicled flap or free flap (e.g., radial forearm, fibula) with microvascular anastomosis
• Airway procedures performed by surgeons
  • Elective tracheostomy (surgical) or tracheostomy as part of laryngectomy
  • Emergency front-of-neck access (FONA): surgical cricothyrotomy/tracheostomy if CICO

Anaesthetic management (overview)

• Type of anaesthesia
  • Usually GA with shared airway; awake airway techniques frequently required (awake fibreoptic or awake videolaryngoscopy)
  • Regional techniques are adjuncts (e.g., scalp blocks not relevant; consider local infiltration/nerve blocks for tracheostomy in selected cases)
• Airway device
  • ETT almost always: oral RAE, reinforced/armoured tube, microlaryngoscopy tube (MLT), nasal RAE (if appropriate), or tracheostomy tube
  • SGA rarely definitive; may be rescue/bridge only if tumour anatomy allows and surgery not involving airway
• Duration
  • Panendoscopy/biopsy: ~0.5–2 h; major resections with free flap: often 6–12+ h
• How painful
  • Panendoscopy: mild–moderate; major resections/neck dissection/free flap: severe (multimodal + opioid infusion/PCA; consider ketamine; avoid excessive sedation if airway risk post-op)
• Key anaesthetic priorities
  • Secure airway safely (often awake), manage shared airway, minimise bleeding/aspiration risk, plan extubation/ICU, anticipate difficult re-intubation and tracheostomy issues

Why head & neck cancer airways are difficult

• Anatomical distortion: tumour mass, supraglottic obstruction, reduced mouth opening (trismus), limited neck movement, friable bleeding tissue
• Functional compromise: stridor, positional obstruction, secretion load, aspiration risk, poor cough, OSA
• Treatment effects: radiotherapy/chemoradiotherapy → oedema, fibrosis, reduced compliance, difficult mask ventilation and laryngoscopy; previous surgery alters landmarks
• Shared airway with surgeon: access conflicts, tube displacement, fire risk (laser/diathermy), need for apnoeic periods

Preoperative assessment (history, exam, investigations)

• Symptoms suggesting critical obstruction
  • Stridor at rest, dyspnoea, inability to lie flat, voice change, dysphagia, drooling, haemoptysis, recurrent aspiration, weight loss/frailty
• Airway history and previous records
  • Prior difficult intubation, prior tracheostomy/laryngectomy, radiotherapy, previous awake technique success/failure, ENT notes and endoscopy images
• Examination
  • Mouth opening (inter-incisor distance), Mallampati, dentition, mandibular protrusion, neck movement, thyromental distance; look for trismus and fixed neck
  • Signs of obstruction: work of breathing, stridor, use of accessory muscles; assess ability to tolerate supine position
  • Nasal patency if considering nasal route; anticoagulation/platelets if epistaxis risk
• Investigations and airway imaging
  • Review CT/MRI neck: level and degree of narrowing, deviation, subglottic/tracheal involvement; discuss with ENT
  • Flexible nasendoscopy findings: glottic view, mobility, supraglottic collapse, secretions
  • Baseline labs: Hb (bleeding), U&E, coagulation; group and save/crossmatch for major surgery
• Comorbidity assessment
  • Smoking/COPD, alcohol-related liver disease, malnutrition, anaemia, cardiac disease; aspiration risk and reflux

Planning and communication

• Make an explicit airway plan with ENT present where possible
  • Plan A (primary), Plan B (backup), Plan C (rescue oxygenation), Plan D (FONA) with triggers for escalation
  • Decide: awake intubation vs asleep; oral vs nasal; fibreoptic vs videolaryngoscope; need for pre-induction tracheostomy
• Environment and staffing
  • Theatre with full difficult airway kit; second anaesthetist; ENT scrubbed/ready for emergency airway; ICU bed if high risk
• Consent and patient counselling
  • Explain awake technique, topicalisation, discomfort, possibility of tracheostomy, postoperative ventilation, dental injury/bleeding risk

Choice of airway strategy (principles)

• Awake tracheal intubation is preferred when loss of airway on induction is likely
  • Indications: stridor/critical narrowing, cannot lie flat, anticipated impossible mask ventilation, large supraglottic tumour, severe trismus, post-radiotherapy fibrosis, high aspiration risk
• Asleep intubation may be acceptable if low risk and clear rescue options
  • Maintain spontaneous ventilation if any doubt; avoid paralysing until ability to ventilate confirmed
  • Consider inhalational induction only with experienced team and clear plan for obstruction; beware worsening dynamic obstruction
• Primary tracheostomy under local anaesthesia
  • Consider if upper airway not safely negotiable (e.g., near-complete obstruction, bleeding tumour, failed awake attempts, severe trismus preventing scope passage)
  • Requires cooperative patient, experienced surgeon, and ability to oxygenate throughout; may be difficult in radiated neck

Awake tracheal intubation: practical approach

• Preparation
  • Standard monitoring + capnography once intubated; IV access; suction ready; difficult airway trolley; backup oxygenation (HFNO) and FONA kit
  • Position head-up; preoxygenate (consider HFNO throughout); avoid oversedation
• Topicalisation (aim: comfortable, cooperative, breathing patient)
  • Lidocaine to nasal/oral cavity, oropharynx, larynx and trachea (nebulised, spray-as-you-go, soaked pledgets, atomiser); consider vasoconstrictor for nasal route
  • Keep within safe local anaesthetic dosing; account for all routes and concentrations
• Sedation (if needed)
  • Titrate to minimal sedation: remifentanil TCI/infusion or dexmedetomidine; maintain verbal contact and airway reflexes
  • Avoid deep sedation in obstructed airway; have reversal/rescue ready (naloxone, airway adjuncts)
• Technique choice
  • Awake fibreoptic intubation (AFOI): useful with limited mouth opening, distorted anatomy; can be nasal or oral (with bite block/airway)
  • Awake videolaryngoscopy (AVL): can be quicker; needs sufficient mouth opening; may be limited by blood/secretions and tumour bulk
• Confirmation and induction
  • Confirm tracheal position with capnography before inducing GA; secure tube well (shared airway, head/neck movement)
  • Only then deepen anaesthesia and consider neuromuscular blockade

Intraoperative management (shared airway cases)

• Tube selection and fixation
  • Reinforced tube reduces kinking; oral RAE for oral surgery; nasal RAE if nasal route appropriate; MLT for laryngeal surgery to improve access
  • Secure firmly; consider throat pack (document in/out); protect eyes and pressure areas in long cases
• Ventilation strategies
  • Controlled ventilation usually; allow apnoeic windows if needed with preoxygenation/HFNO; close communication with surgeon
  • Be prepared for tube displacement/obstruction by blood/secretions; frequent suction and capnography vigilance
• Fire risk (laser/diathermy in airway)
  • Minimise FiO2, avoid N2O, use laser-safe tube when indicated, saline/wet swabs available; agreed fire drill
• Haemorrhage and aspiration
  • Large-bore IV access, arterial line for major cases; crossmatched blood; cell salvage may be used depending on tumour policy
  • Protect lungs: cuff pressure, suction, consider bronchoscopy if contamination suspected
• Analgesia and PONV
  • Multimodal: paracetamol, NSAID if appropriate, opioids (often infusion/PCA), ketamine; consider dexmedetomidine for opioid-sparing
  • PONV prophylaxis important (bleeding/airway risk if vomiting)
• Free flap considerations
  • Maintain flap perfusion: avoid hypotension, anaemia, hypothermia; cautious vasopressors (often acceptable in titrated doses); good analgesia and normocapnia

Extubation and postoperative airway strategy

• Extubation is high risk: plan early and document
  • Factors favouring delayed extubation/ICU: airway oedema, difficult intubation, major resection, bleeding risk, free flap bulk, OSA, aspiration risk, prolonged surgery, significant fluid shifts
• Options
  • Elective tracheostomy (often safest) for major oral cavity/oropharyngeal resections or anticipated swelling
  • Delayed extubation in ICU with sedation/ventilation and planned re-assessment
  • Awake extubation with airway exchange catheter (AEC) in selected cases; ensure immediate re-intubation plan and skilled staff
• Postoperative complications to anticipate
  • Airway obstruction (oedema/haematoma/flap), bleeding, aspiration, laryngospasm/bronchospasm, tracheostomy blockage/displacement, pain and agitation

Tracheostomy and laryngectomy-specific airway points

• Tracheostomy
  • Early problems: bleeding, false passage, displacement (especially fresh tracheostomy), pneumothorax, subcutaneous emphysema, blockage with secretions
  • Emergency approach: call for help, oxygen to face and stoma, suction, remove inner cannula, attempt to pass suction catheter; if cannot ventilate, remove tube and oxygenate via stoma; oral intubation may be possible depending on upper airway
• Total laryngectomy
  • Patient is a permanent neck breather: upper airway is disconnected from trachea; ventilation/intubation must be via stoma only
  • In emergency: apply oxygen to stoma; if needed, intubate stoma with cuffed tube; do not attempt oral/nasal ventilation

CICO and emergency FONA in head & neck cancer

• Higher risk of CICO due to obstruction + difficult mask ventilation
• Have a low threshold to move to FONA if oxygenation failing
  • Radiated neck/tumour may make landmarks difficult; ensure experienced operator and scalpel-bougie-tube technique readiness
• ENT presence is valuable but do not delay oxygenation attempts