What are the guidelines for awake tracheal intubation?

Guidelines for Awake Tracheal Intubation

Awake tracheal intubation must be considered in the presence of predictors of difficult airway management and should follow a systematic approach focusing on preparation, performance, and post-procedure management to ensure patient safety. 1, 2

Indications and Decision Making

• Awake tracheal intubation is considered the gold standard for managing predicted difficult airways 3
• Despite its high success rate and favorable safety profile, it is underutilized (only 0.2% of all intubations in the UK) 1
• Key benefit: Maintains spontaneous ventilation and intrinsic airway tone until the trachea is intubated 1

Preparation and Equipment

• A cognitive aid or checklist is strongly recommended before and during performance of awake tracheal intubation 1, 2
• Essential equipment must include:
  • Flexible bronchoscope or videolaryngoscope
  • Topical anesthetics
  • Sedative medications
  • Oxygen delivery systems
  • Emergency airway equipment 2

The sTOP Framework for Performance

1. Sedation

• Cautious use of minimal sedation is beneficial but not mandatory 1, 2
• Sedation should ideally be administered by an independent practitioner 1
• Important: Sedation should not substitute for inadequate airway topicalization 1
• Effective regimens include:
  • Midazolam (0.02-0.05 mg/kg) with fentanyl (2.2-2.3 μg/kg) 4
  • Remifentanil at ED50 of 0.62 μg/kg bolus followed by 0.062 μg·kg⁻¹·min⁻¹ infusion when combined with midazolam 0.1 mg/kg 5

2. Topicalization

• Effective topicalization must be established and tested before proceeding 1, 2
• Maximum lidocaine dose should not exceed 9 mg/kg lean body weight 1, 2
• Complete upper airway anesthesia can be achieved through:
  • Bilateral glossopharyngeal nerve blocks
  • Bilateral superior laryngeal nerve blocks
  • Recurrent laryngeal nerve block 2
• For nasal routes, phenylephrine 0.5% combined with lidocaine is recommended to reduce epistaxis 2
• Caution: Avoid cocaine due to potential toxic cardiovascular complications 2
• Monitor for signs of local anesthetic toxicity (lightheadedness, perioral numbness, tinnitus) 2

3. Oxygenation

• Supplemental oxygen should always be administered during the procedure 1, 2
• This is particularly mandatory in pediatric patients 2

4. Performance

• Limit attempts to three, with one further attempt by a more experienced operator (3+1 rule) 1, 2
• Verify tracheal tube position with a two-point check:
  1. Visual confirmation (tracheal lumen with flexible bronchoscope or tube through cords with videolaryngoscope)
  2. Capnography to exclude esophageal intubation 1, 2
• Critical: Only induce anesthesia after confirming correct tracheal tube position 1, 2

Post-Procedure Management

• Patients should remain nil by mouth for at least 2 hours following airway topicalization due to prolonged effect on laryngeal reflexes 2
• Thorough documentation of the technique used is essential for future airway management 2

Complications and Their Management

• Potential complications include:
  • Respiratory depression
  • Hemodynamic instability
  • Inadequate topicalization leading to cough, laryngospasm, or bronchospasm 2
  • Unsuccessful ATI (1-2% of cases) 1
• Have lipid emulsion available in case of local anesthetic toxicity 2

Training and Competency

• All departments should support anesthesiologists in attaining and maintaining competency in awake tracheal intubation 1, 2
• Regular practice and simulation are essential to maintain skills 2
• Despite being a crucial skill for patient safety, ATI is practiced infrequently (1-2% of all intubations) 3

Common Pitfalls and How to Avoid Them

1. Inadequate topicalization: Ensure thorough application and testing of local anesthetics before proceeding
2. Over-sedation: Remember that the goal is minimal sedation that maintains spontaneous ventilation
3. Rushing the procedure: Allow adequate time for topical anesthetics to take effect
4. Exceeding maximum local anesthetic dose: Calculate and track cumulative doses, especially when combining with other procedures requiring local anesthesia
5. Failure to confirm tube placement: Always perform the two-point check before inducing anesthesia

By following these guidelines systematically, clinicians can improve the success rate and safety profile of awake tracheal intubation, making it more accessible for managing difficult airways.