What are the recommended approaches for managing a difficult airway in patients with restricted neck extension?

Difficult Airway Management with Restricted Neck Extension

In patients with restricted neck extension, awake fiberoptic intubation is the gold standard approach, as it allows for minimal cervical manipulation while maintaining spontaneous ventilation and airway control 1.

Primary Approach: Awake Intubation

Awake intubation should be performed when restricted neck extension is combined with any of the following 1:

• Anticipated difficult mask ventilation or supraglottic airway ventilation
• Increased aspiration risk
• Patient unable to tolerate brief apneic episodes
• Expected difficulty with emergency invasive airway rescue

Technique Selection for Awake Approach

Flexible fiberoptic bronchoscopy (nasotracheal or orotracheal) remains the preferred method for severe cervical restriction, as demonstrated in recent case reports of ankylosing spondylitis patients with complete loss of cervical mobility 2, 3. This can be facilitated with:

• Remifentanil infusion for sedation while maintaining spontaneous breathing 2, 3
• Topical anesthesia (lidocaine) to airway structures 2, 3

When fiberoptic equipment is unavailable, awake videolaryngoscopy under remifentanil sedation with topical anesthesia is an acceptable alternative 2. The C-MAC D-Blade has been successfully used in this context 2.

Alternative Noninvasive Approaches

If proceeding after induction is deemed safer (benefits outweigh risks), the following sequence is recommended 1:

First-Line Devices:

• Videolaryngoscopy with adjuncts (bougies, stylets)
• Combination techniques: videolaryngoscope + flexible bronchoscope (higher first-attempt success rates) 1
• Supraglottic airways as rescue devices or conduits for fiberoptic intubation

Novel Adjuncts:

A catheter-assisted modification technique (epidural catheter threaded through ETT to provide anterior deflection) has shown technical feasibility in a single case report, though this requires further validation 4.

Critical Positioning Considerations

A major caveat: While maximal neck extension is recommended for emergency front-of-neck airway (eFONA) procedures 5, this is contraindicated in patients with restricted neck mobility due to cervical pathology (e.g., ankylosing spondylitis, cervical fractures). In these patients:

• Maintain neutral cervical alignment during intubation attempts 3
• Do NOT force neck extension, as this risks spinal cord injury
• For supraglottic airway insertion when standard positioning fails, shoulder elevation with jaw thrust can facilitate placement 6

Emergency Front-of-Neck Airway (Plan D)

If a "cannot intubate, cannot oxygenate" (CICO) scenario develops, proceed with eFONA using the vertical scalpel-bougie-tube technique 5:

Key modifications for restricted neck extension:

• Attempt to achieve maximal neck extension "where feasible" 5 - but recognize this may be impossible in your patient population
• If extension is contraindicated, proceed with available positioning
• Consider retaining or reinserting a supraglottic airway during eFONA, as this increases cricothyroid membrane height by 26% 7
• Use full neuromuscular blockade before eFONA 5

The DAS 2025 vertical technique involves: 8 cm vertical midline skin incision → blunt finger dissection → identify cricothyroid membrane → transverse stab incision → rotate scalpel 90° caudally → railroad bougie alongside blade → advance 6.0 mm cuffed tube over bougie 5.

Algorithm for Decision-Making

Step 1: Assess severity of neck restriction + other difficult airway features

Step 2: If severe restriction (e.g., ankylosing spondylitis, cervical fracture):

• Choose awake fiberoptic intubation (nasotracheal or orotracheal)
• If unavailable → awake videolaryngoscopy
• If patient uncooperative → consider elective surgical airway by trained surgeon 1

Step 3: If moderate restriction with cooperative patient:

• Awake approach still preferred
• If declining awake intubation → videolaryngoscopy after induction with immediate eFONA readiness

Step 4: Monitor time, attempts, and oxygen saturation continuously 1

• Limit intubation attempts to avoid trauma
• Test mask ventilation after each attempt when feasible

Step 5: If CICO develops → immediate eFONA without delay 5

Common Pitfalls

• Forcing neck extension in patients with cervical pathology - this can cause catastrophic spinal cord injury
• Proceeding with asleep intubation without eFONA preparation - restricted neck extension makes both intubation AND emergency cricothyroidotomy more difficult
• Multiple intubation attempts without calling for help - each attempt increases trauma and edema
• Removing supraglottic airway before eFONA - evidence suggests retaining it may improve cricothyroid membrane access 7