What topics should be prepared for a fiberoptic intubation viva, including indications, contraindications, equipment, patient preparation, sedation, technique, troubleshooting, alternative airway strategies, and potential complications?

Fiberoptic Intubation Viva Preparation Guide

For your fiberoptic intubation viva, you must master the 2022 ASA Difficult Airway Algorithm framework, awake intubation decision-making criteria, and the technical execution of airway topicalization and sedation protocols. 1, 2

Core Decision-Making Framework

When to Choose Awake Fiberoptic Intubation

Any single "YES" answer mandates consideration of awake intubation 1:

• Suspected difficult laryngoscopy/intubation with direct or video laryngoscope?
• Suspected difficult ventilation with facemask or supraglottic device?
• Significantly increased risk of aspiration?
• Increased risk of rapid desaturation?

The 2022 ASA guidelines explicitly position flexible bronchoscopy as a primary awake intubation technique alongside videolaryngoscopy and direct laryngoscopy 1. This represents the gold standard approach when you cannot guarantee post-induction ventilation 2.

Absolute Indications You Must Know

Prepare to discuss these clinical scenarios where awake fiberoptic intubation is the safest choice 2, 3:

• Anticipated difficult airway with concurrent difficult mask ventilation
• Cervical spine instability requiring immobilization
• Hypophyseal and craniofacial surgery with anatomic distortion
• Upper airway masses or tumors
• Severe maxillofacial trauma
• Morbid obesity with multiple predictors of difficulty

Contraindications

Relative contraindications include 2:

• Patient refusal or inability to cooperate
• Local anesthetic allergy (extremely rare)
• Severe coagulopathy with bleeding risk
• Time-critical emergencies where awake technique would delay definitive airway

Equipment Checklist

You must demonstrate systematic equipment preparation 2:

Essential Components

• Fiberoptic bronchoscope (appropriate size: typically 4.0-5.0mm outer diameter for adults)
• Endotracheal tube (loaded and lubricated)
• Bite block
• Oxygen delivery system (nasal cannula or specialized oxygen port)
• Suction apparatus
• Topical anesthesia delivery devices
• Monitoring equipment (pulse oximetry, capnography, blood pressure)

The 2020 Difficult Airway Society guidelines strongly recommend using a cognitive aid or checklist before and during awake tracheal intubation 2. This is a high-yield viva point.

Patient Preparation Protocol

Airway Topicalization

Maximum lidocaine dose: 9 mg/kg lean body weight 2. This is a critical safety limit you must state.

Effective topicalization techniques include 2, 4:

• Nebulized lidocaine (4-5 mL of 4% solution)
• "Spray-as-you-go" through the working channel
• Superior laryngeal nerve blocks (bilateral)
• Transtracheal injection
• Atomized lidocaine to oropharynx and tongue base

The evidence shows all local anesthesia methods perform similarly well, with no significant differences in success rates 4. Choose the technique matching your experience level.

Antisialagogue Administration

Glycopyrrolate 0.2-0.4 mg IV or IM 30-60 minutes pre-procedure 5. This reduces secretions that obscure visualization—a common pitfall leading to failed attempts.

Sedation Strategy

Cautious minimal sedation can be beneficial but should never substitute for inadequate topicalization 2. Ideally administered by an independent practitioner.

Evidence-Based Sedation Options

Dexmedetomidine offers the best safety profile 4:

• Significantly fewer desaturation episodes versus propofol and opioids (RR 0.51,95% CI 0.28-0.95)
• Maintains spontaneous ventilation
• Provides anxiolysis without respiratory depression
• Typical dosing: 0.5-1.0 mcg/kg loading over 10 minutes, then 0.2-0.7 mcg/kg/hr

Alternative regimens 4:

• Remifentanil: similar desaturation risk to propofol but requires careful titration
• Sevoflurane: lower apnea incidence versus propofol (RR 0.43,95% CI 0.22-0.81)
• Midazolam + opioid combinations: acceptable but higher desaturation risk

Critical pitfall: Over-sedation leading to loss of airway reflexes and inability to follow commands defeats the purpose of awake intubation 2.

Oxygenation Throughout

Supplemental oxygen must always be administered during awake tracheal intubation 2. Options include:

• Low-flow or high-flow nasal cannula
• Oxygen port on bronchoscope
• Nasal prongs maintained during oral approach

The 2022 ASA guidelines emphasize head-elevated positioning and consideration of noninvasive ventilation during preoxygenation 1.

Technical Execution

The "3+1 Rule"

Limit attempts to three, with one additional attempt by a more experienced operator 2. This is a patient safety mandate to prevent airway trauma, edema, and bleeding that worsen subsequent attempts.

Verification of Tube Position

Two-point check before inducing anesthesia 2:

1. Visual confirmation of tube passing through vocal cords
2. Capnography demonstrating end-tidal CO₂

Never induce general anesthesia until both criteria are met. This prevents the catastrophic scenario of inducing anesthesia with an esophageal intubation.

Nasal vs. Oral Approach

Be prepared to discuss advantages of each:

• Nasal: Better tolerated, easier midline approach, hands-free, but risk of epistaxis
• Oral: Larger tube possible, avoids nasal trauma, but requires bite block and more patient cooperation

Troubleshooting Common Problems

Poor Visualization

Systematic approach 6:

1. Suction secretions/blood
2. Apply additional topical anesthesia
3. Reposition patient (head extension, jaw thrust)
4. Use anti-fog solution on scope tip
5. Consider alternative route (nasal if oral, or vice versa)

Patient Intolerance

If patient cannot tolerate procedure despite adequate preparation 2:

• Do NOT force the procedure
• Consider postponing with better preparation
• Reassess whether awake technique is truly necessary
• Alternative: proceed with induction if ventilation predicted to be adequate, with backup plans ready

Failed Awake Intubation

The 2022 ASA algorithm provides clear guidance 1:

• If unstable or cannot be postponed: may proceed to induction pathway WITH preparations for emergency invasive airway
• If stable: postpone and return with appropriate resources (personnel, equipment, patient preparation)
• Consider alternative awake techniques or elective invasive airway

Complications You Must Discuss

Success rate is high (99.4% in systematic review) with low complication rate (0.34% severe adverse events, zero deaths) 4.

Potential Complications

• Local anesthetic toxicity: Respect 9 mg/kg lidocaine limit 2
• Epistaxis: More common with nasal approach
• Laryngospasm: Usually from inadequate topicalization
• Aspiration: Risk reduced compared to post-induction approach in high-risk patients
• Airway trauma: Prevented by limiting attempts 2
• Cardiovascular responses: Hypertension, tachycardia from sympathetic stimulation 3

Alternative Airway Strategies

If fiberoptic intubation fails or is unavailable, the 2022 ASA algorithm specifies 1:

• Videolaryngoscopy (awake or asleep depending on assessment)
• Combined techniques (e.g., video-assisted fiberoptic)
• Intubating supraglottic airway with fiberoptic guidance
• Retrograde wire-aided intubation
• Emergency invasive airway (surgical cricothyrotomy, needle cricothyrotomy with pressure-regulated device)

The algorithm emphasizes calling for help early and being aware of time passage 1.

Post-Intubation Management

Follow-up care includes 1:

• Postextubation monitoring for airway edema
• Consider steroids or racemic epinephrine if significant airway manipulation
• Patient counseling about the difficult airway
• Documentation in medical record
• Team debriefing
• Encourage patient enrollment in difficult airway registry 1

Training and Competency

All departments should support anaesthetists to attain competency and maintain skills in awake tracheal intubation 2. The 2020 DAS guidelines make this an institutional responsibility, not just individual practitioner responsibility.

Recent evidence demonstrates that simulation-based training with task trainers significantly improves knowledge and self-efficacy for superior laryngeal nerve blocks and transtracheal blocks 7. This addresses the challenge that infrequent clinical exposure complicates skill acquisition 6.

Key Viva Pitfalls to Avoid

1. Never state you would induce anesthesia before confirming tube position with two-point check 2
2. Never exceed 9 mg/kg lidocaine 2
3. Never use sedation as substitute for inadequate topicalization 2
4. Never make unlimited intubation attempts—respect the 3+1 rule 2
5. Never fail to have a backup plan—know the emergency pathway 1

The fiberoptic bronchoscope remains indispensable for predicted difficult airways despite modern videolaryngoscopy 8. Your viva examiners expect you to demonstrate when it is the safest first choice, not just an alternative technique.