Fibre Optic Intubation (FOI)

Overview

Indications

• Trismus, mandibular/maxillofacial injury
• Cervical spine rigidity or suspected instability
• Obstructing mass in the oral cavity or upper aerodigestive tract
• Laryngeal tumours (especially post-radiotherapy)
• Distorted airway anatomy (infection, abscess, swelling, burns, trauma)

• Upper airway obstruction
• Tracheal compression

• High risk of aspiration
• Movement of the neck undesirable
• Known difficult mask ventilation
• Morbid obesity
• Patient self-positioning required

• Roberts and Hedges' Clinical Procedures in Emergency Medicine, p. 144
• Cummings Otolaryngology, p. 126

Contraindications

Note: Fixed stenotic lesions at all levels that will not allow ETT passage without dilation are also a contraindication to awake FOI.

Equipment

• Flexible fibreoptic bronchoscope (FOB): Practical diameter ~4-5 mm for intubation. ETT should be ~1 mm larger than the scope diameter (e.g., 5 mm scope takes a 6.0 ETT).
• Working channel (~2 mm): Allows suction, oxygen insufflation, and passage of catheters.
• Video monitor system: Modern scopes plug into a video monitor - essential for training and assistant guidance.
• Oral intubating airways: Williams Airway Intubator or Ovassapian Airway - guide the scope/ETT in the oral approach and prevent scope damage from biting.
• ETT softened in warm saline, cuff fully deflated before insertion.
• Lubrication for scope and nasal trumpets.
• Anesthesia cart with resuscitation and monitoring equipment.

Patient Preparation

Psychological Preparation

Pharmacological Preparation

• Glycopyrrolate (preferred) - does not cross the blood-brain barrier, causes less tachycardia. Given ~30 minutes before the procedure. Reduces secretions and optimises topical anaesthesia efficacy.

• Calm patients: light or no sedation
• Most patients: conscious sedation (IV midazolam ± fentanyl; remifentanil infusion is an option)
• Severely compromised airways: NO sedation or opioids prior to procedure
• Goal: calm, cooperative patient who can follow commands and maintain airway/breathing

• Benzocaine 20% spray - gargle and swallow
• Nebulised 2% lidocaine (5 mL) if time permits
• 4-5% lidocaine cream "buttered" at base of tongue (anesthetises tongue, vallecula, epiglottis via posterior flow)
• Transcricothyroid injection: 2 mL of 2% lidocaine through the cricothyroid space (instruct patient to cough)
• Bilateral/unilateral superior laryngeal nerve block with 2% lidocaine as needed

• Oxymetazoline 0.05% or phenylephrine 1% nasal spray (vasoconstriction, reduces epistaxis risk)
• 4% lidocaine nasal spray or cotton pledgets soaked in 4% lidocaine between turbinates and septum
• Nasal trumpets in increasing sizes (lubricated with lidocaine gel) to dilate the naris

Maximum dose of topical lidocaine must be respected - absorption from respiratory mucosa is faster than from injections.

• Roberts and Hedges' Clinical Procedures, p. 145
• Cummings Otolaryngology, p. 126-128

Technique

Nasal Approach (generally preferred by otolaryngologists)

1. Head of bed elevated as much as tolerated.
2. Naris dilated with sequential nasal trumpets lubricated with lidocaine gel.
3. ETT (warmed in saline, cuff deflated) placed in the nostril and directed inferiorly toward the nasopharynx.
4. If the ETT doesn't bend toward the oropharynx - pull back, rotate 90° left or right, reintroduce.
5. Fibreoptic bronchoscope (connected to video monitor) passed through the ETT.
6. Operator stands facing the patient with the video monitor in view.
7. Navigate the scope through the nasopharynx, past the epiglottis, and through the vocal cords.
8. Jaw thrust or gentle tongue traction may be needed if the epiglottis falls against the posterior pharyngeal wall.
9. Once the scope is in the trachea (confirmed by tracheal rings and carina), the ETT is railroaded over the scope ("railroading").
10. A counterclockwise rotation of ~90° on the ETT may be needed to pass the arytenoids as the tube advances over the scope tip.
11. Confirm position (carina visible, bilateral breath sounds, capnography), then withdraw the scope.

Oral Approach

• An oral intubating airway (Williams or Ovassapian) is inserted first to guide the scope, prevent biting, and aim the tip toward the glottis.
• ETT is pre-mounted on the scope, both passed through the intubating airway together.
• An assistant can hold the oral airway and make adjustments.
• Once the scope passes the vocal cords, the ETT is advanced over it.
• The oral airway can be left as a bite block or removed over the ETT after removing the tube adapter (split-away designs allow this).

Two-Person Technique (oral, alternative)

• One clinician performs direct laryngoscopy to expose the hypopharynx.
• A second clinician advances the scope under the epiglottis toward the glottis using the laryngoscopist's guidance.
• Rarely used - most such patients can be managed with videolaryngoscopy + bougie.

Keys to Success (Box 6.2 - Cummings)

1. Expert endoscopist
2. Functioning bronchoscope and supplies checked
3. Proper patient preparation (psychological + pharmacological)
4. Adequate topical anaesthesia
5. Head of bed elevated
6. Suction the airway before attempting - secretions are the most common obstacle
7. Adequate lubrication on the scope

Scope Handling Technique

• Scope body and controls held in one hand; the other hand stabilises the sheath at the point of entry into the ETT or patient.
• Motion in one plane is controlled with the deflection lever; perpendicular motion requires rotation of the scope body (keep the sheath taut between scope body and entry point - slack prevents effective rotation at the tip).

Complications

Success Rates and Limitations

• In expert hands (experienced anesthesiologists/ENT surgeons): ~100% success rate for difficult airways.
• In the ED with less experienced operators: 50-90% success.
• Most common failure cause in the OR: clinician inexperience.
• Most common failure cause in the ED: poor visibility (blood, vomitus, secretions).
• If intubation attempt exceeds 3 minutes without success - consider alternative approach.
• Equipment is expensive, fragile, and requires ongoing maintenance of technical skills.

Summary: When to Choose FOI

• Bailey and Love's Short Practice of Surgery 28th ed., p. 820
• Cummings Otolaryngology Head and Neck Surgery, pp. 125-129
• Roberts and Hedges' Clinical Procedures in Emergency Medicine, pp. 143-148