What are the guidelines for managing difficult airways in 2022?

2022 Difficult Airway Management Guidelines

The 2022 difficult airway management guidelines emphasize using videolaryngoscopy as the first-line approach for patients with suspected or confirmed difficult airways, with a structured algorithm for rescue techniques when initial attempts fail. 1

Airway Assessment and Prediction

Key Assessment Components:

• Predictors of difficult direct laryngoscopy:
  • Modified Mallampati classification (Class 3-4 correlates with Cormack-Lehane Grade 2-4) 2
  • Thyromental distance (highest sensitivity and negative predictive value) 3
  • Upper lip bite test (highest specificity) 3
  • Inter-incisor gap
  • Atlantooccipital extension
  • LEMON assessment (Look, Evaluate, Mallampati, Obstruction, Neck mobility)

Risk Stratification:

• Multiple attempts at tracheal intubation increase patient morbidity 4
• When difficulty is anticipated, limit attempts to maximum of three with any chosen device 4
• Consider awake approach when multiple aspects of airway management are predicted to be difficult 5

Management Algorithm for Difficult Airways

First-Line Approach:

• Videolaryngoscopy is recommended as first-line for patients with suspected or confirmed difficult airways (Grade A; moderate recommendation) 1
• No specific videolaryngoscope type or blade is recommended over others 1
• Regular training with videolaryngoscopy in simulated difficult airway scenarios is essential 1

Airway Techniques:

1. For basic airway maneuvers:

   • Use jaw thrust rather than head tilt-chin lift when cervical spine injury is suspected 1
   • Minimize cervical spine movement during pre-oxygenation and facemask ventilation 1

2. For supraglottic airway devices (SADs):

   • Second-generation SADs are preferred over first-generation devices 1
   • Use familiar devices when intubating through an SAD 1
   • Consider using adjuncts (stylet or bougie) when performing tracheal intubation 1

3. For predicted difficult intubation:

   • Consider awake tracheal intubation when:
     • Impossible videolaryngoscopy or direct laryngoscopy is predicted
     • Multiple modes of airway management are predicted to be difficult
     • Physiological or contextual issues increase risk 5

Rescue Techniques:

1. If initial intubation fails:

   • Transition through algorithm promptly
   • Declare difficulty to the team at each stage
   • Consider second-generation SAD between attempts (better seal, less aerosol generation) 1

2. Cannot Intubate, Cannot Oxygenate (CICO) scenario:

   • Follow emergency front-of-neck airway (FONA) protocol
   • Scalpel-bougie-tube technique is preferred (especially in COVID-19 patients) 1
   • Maximum three attempts at each lifeline before escalating 1

Post-Intubation Management

1. After successful intubation:

   • Inflate cuff to 20-30 cmH₂O pressure immediately 1
   • Secure tube and confirm placement with waveform capnography 1
   • Document depth of insertion prominently 1
   • Consider early placement of nasogastric tube to minimize later interventions 1

2. Ongoing management:

   • Use closed tracheal suction when available 1
   • Monitor cuff pressure and tube depth at every shift 1
   • Check tube position before and after patient repositioning 1
   • Document and communicate difficult airway details at shift changes 1

Common Pitfalls and Caveats

• Overreliance on single predictors: No single airway test provides high sensitivity and specificity; combine multiple tests 3
• Delayed recognition of failure: Define clear triggers for moving from one technique to the next 5
• Inadequate preparation: Ensure difficult airway equipment is readily available before induction 5
• Failure to anticipate: Preoperative anticipation of difficult airways occurs in only 50% of cases; always have a backup plan 6
• Extubation risks: Carefully plan extubation of at-risk patients, including assessment of tolerance for airway support withdrawal 5

The guidelines emphasize that while prediction tools are helpful, unanticipated difficulty can always occur, necessitating a prepared strategy for every patient and institutional readiness with appropriate equipment.