What is the step-by-step approach for airway blocks in preparation for awake intubation in a patient with a predicted difficult airway and history of neck surgery, radiation, or respiratory disease?

Step-by-Step Airway Blocks for Awake Intubation

For awake intubation in patients with predicted difficult airways, perform systematic topical anesthesia of the airway using a combination of direct application to nasal passages, oropharynx, and larynx, supplemented by targeted nerve blocks to achieve complete anesthesia from the nares to the vocal cords. 1

Patient Preparation Before Nerve Blocks

Positioning and Oxygenation

• Position the patient head-up (30-45 degrees) to reduce aspiration risk and improve respiratory mechanics 2
• Initiate active pre-oxygenation with high-flow nasal oxygen before beginning topicalization 2
• Maintain continuous oxygen supplementation throughout the entire procedure 3

Psychological Preparation

• Explain the procedure in simple language to reduce patient anxiety 4
• Titrate sedative medications carefully to achieve patient comfort without compromising airway patency 4
• Ensure minimal sedation only—the patient must remain cooperative and able to maintain their airway 2

Topical Anesthesia Application

Nasal Passage Preparation (for nasotracheal approach)

• Apply topical local anesthetic (typically lidocaine 4-10%) directly to both nasal passages using cotton pledgets or atomized spray 2
• Allow 3-5 minutes for adequate mucosal anesthesia before proceeding 4
• Consider using a vasoconstrictor (phenylephrine or oxymetazoline) to reduce bleeding risk 2

Oropharyngeal Anesthesia

• Apply topical anesthetic to the oropharynx using spray, gargle, or "swish and swallow" technique 1, 2
• Target the base of tongue, posterior pharyngeal wall, and tonsillar pillars 4
• Multiple applications may be needed to achieve adequate depth of anesthesia 1

Laryngeal and Tracheal Anesthesia

• Apply local anesthetic directly to the larynx and vocal cords 1, 2
• Ensure vocal cords are open and non-reactive before advancing any instruments 1, 2
• Consider "spray-as-you-go" technique through the fiberoptic scope's working channel for deeper airway structures 4

Specific Nerve Blocks (Optional but Recommended)

While the guidelines emphasize topical anesthesia as the primary method 1, 2, targeted nerve blocks can supplement topical techniques in challenging cases 4. The specific nerve blocks are not detailed in the highest-quality guidelines provided, but clinical practice typically includes:

• Glossopharyngeal nerve block: For posterior tongue and oropharynx
• Superior laryngeal nerve block: For supraglottic structures
• Transtracheal injection: For subglottic trachea and vocal cords

Critical Safety Considerations

Dosing and Timing

• Topical lidocaine has dose-dependent duration of 40 minutes, but return of laryngeal reflexes may take longer 1
• Keep patients nil by mouth for at least 2 hours following airway topicalization 1
• Monitor total local anesthetic dose to avoid systemic toxicity 4

Equipment and Backup Planning

• Have difficult airway equipment immediately available including videolaryngoscope, flexible bronchoscope, and supraglottic devices 1, 2
• Ensure an individual trained in front-of-neck airway (FONA) techniques is present 1
• Formulate a clear backup plan for failed awake intubation before starting 2

Monitoring During Procedure

• Maintain continuous pulse oximetry and capnography monitoring 4
• Limit attempts to maximum 3 attempts plus 1 additional by the most experienced operator 1, 2
• If awake intubation fails, immediately call for help, apply 100% oxygen, stop and reverse sedatives, and prepare for emergency FONA 1, 2

Common Pitfalls to Avoid

• Inadequate topicalization: Rushing the procedure before achieving complete anesthesia leads to patient discomfort, coughing, and failed intubation 4
• Excessive sedation: Over-sedation compromises airway patency and patient cooperation, defeating the purpose of awake intubation 2, 4
• Poor communication: Failing to explain the procedure adequately increases patient anxiety and reduces cooperation 4
• Ignoring anatomical distortion: In patients with neck surgery, radiation, or tumors, standard landmarks may be unreliable—use fiberoptic visualization throughout 5

Post-Intubation Management

• Verify tracheal placement with continuous waveform capnography before removing the fiberoptic scope 2
• Document the technique used, number of attempts, and any difficulties encountered 1
• Plan for high-risk extubation following Difficult Airway Society extubation guidelines, as these patients remain at elevated risk 1