Airway Management in Head and Neck Surgery

Airway Anatomy & Challenges - Neck's Tricky Terrain

• Core Anatomy: Larynx (supraglottis, glottis, subglottis), pharynx, trachea.
• Key Spaces: Pre-epiglottic, paraglottic, retropharyngeal - critical for pathology spread & airway assessment.
• Common Challenges:
  • Distortion: Tumors, edema (post-op, infection, angioedema), hematoma.
  • Fixation: Post-radiation fibrosis, surgical scarring, trismus.
  • Limited Access: ↓ Neck mobility (e.g., cervical spondylosis, prior surgery).
  • Obstruction: Blood, secretions, foreign body.
  • Shared surgical field.

⭐ Ludwig's angina, a rapidly spreading cellulitis of the floor of mouth, can cause acute airway obstruction via posterior and superior tongue displacement, often requiring urgent airway intervention.

Preoperative Assessment - Predicting Peril

• History: Prior difficult airway, H&N surgery/RT (fibrosis, trismus), OSA, stridor.
• Examination:
  • Mouth opening < 3 cm
  • TMD < 6 cm / 3 fingerbreadths
  • Mallampati III/IV
  • Neck: Mobility ↓ (< 35° ext.), ↑circumference, mass.
  • Mandibular protrusion (ULBT Class II/III)
  • Dentition (loose/prominent).
• 📌 LEMON (Difficult Laryngoscopy):
  • Look: facial trauma, large tongue
  • Evaluate 3-3-2 rule
  • Mallampati score
  • Obstruction/Obesity: tumor, goiter
  • Neck mobility ↓

⭐ Radiotherapy in H&N cancer significantly ↑ difficult intubation risk (fibrosis, ↓ mobility).

Difficult Airway Techniques - Navigating Narrow Paths

• Awake Intubation: Gold standard for anticipated difficult airway.
  • Techniques: Fiberoptic (FOB), Video Laryngoscopy (VL).
  • Prep: Antisialagogue (Glycopyrrolate 0.2-0.4 mg), airway anesthesia (topical, nerve blocks).
• Video Laryngoscopy (VL):
  • Types: C-MAC, GlideScope.
  • Better view in ↓mouth opening, ↓neck mobility.
• Optical Stylets/Lightwands:
  • e.g., Shikani, Bonfils; Trachlight (lightwand).
  • Aid ETT placement via transillumination or direct vision.
• SADs as Intubation Conduits:
  • e.g., LMA Fastrach (ILMA), i-gel.
  • Allows ventilation then intubation.
• Retrograde Intubation: Invasive, guidewire via cricothyroid membrane.

⭐ Awake Fiberoptic Intubation (AFOI) is the technique of choice for an anticipated difficult airway, maintaining spontaneous ventilation.

Surgical Airways - Lifesaving Incisions

Indicated in CICO ("Can't Intubate, Can't Oxygenate"), failed intubation, or if intubation contraindicated (e.g., severe facial/laryngeal trauma).

• Cricothyroidotomy (CCT):
  • Quickest access via cricothyroid membrane.
  • Lifesaving, temporary; convert to tracheostomy within 24 hrs.
  • Types: Needle (children < 12 yrs), Surgical.
  • ⚠️ Risks: Bleeding, perforation, subglottic stenosis.
• Tracheostomy:
  • Definitive airway for prolonged ventilation or upper airway obstruction.
  • Incision: Horizontal/Vertical, typically between 2nd-4th tracheal rings.
  • Types: Percutaneous, Open.
  • Complications: Early (bleeding, pneumothorax), Late (stenosis, TIF).

⭐ In emergent CICO, surgical cricothyroidotomy is preferred over needle cricothyroidotomy in adults due to better ventilation.

Post-Op & Extubation - Guarding the Exit

• Post-Op Vigilance: Continuous SpO2, watch for stridor, distress.
• Extubation Criteria:
  • Awake, alert, cooperative.
  • Spontaneous ventilation: TV > 5 ml/kg, RR < 30/min, NIF > -20 cm H2O.
  • Positive Cuff Leak Test (CLT).
• Extubation Flow:

• Care After: Humidified O2, nebulized adrenaline for stridor.

  ⭐ Absence of cuff leak (airway edema) is a major predictor of post-extubation stridor; consider steroids 6-12h prior if high risk.

High‑Yield Points - ⚡ Biggest Takeaways

• Difficult airway is common in H&N surgery from tumors, radiation, or prior surgery.
• Preoperative airway assessment (Mallampati, TMD, neck mobility) is crucial.
• Awake Fiberoptic Intubation (AFOI) is gold standard for anticipated difficult intubation.
• Maintain readiness for surgical airway (tracheostomy/cricothyroidotomy).
• Video laryngoscopy can be a key adjunct for intubation.
• Strict extubation criteria are vital due to edema/hematoma risks.
• Post-operative stridor is an emergency needing immediate intervention.