Difficulty visualizing the larynx

Causes

• Reduced airspace passage due to sedation, edema or obesity
• Supraglottic mass
• Distorted anatomy or deviated larynx
• Vision obscured by blood or secretions
• "Red out" – scope is likely to be in the piriform fossa or esophagus, or impacted on mucosa

Remedies

• Ask patient to protrude the tongue or phonate or breathe deeply. Alternatively, the tongue may be retracted by an assistant holding it between a folded gauze
• Use an oral intubating device
• If an oral intubating device is already in place, ensure that it is midline and withdraw slightly
• Get assistant to perform gentle jaw thrust - this elevates the tongue and epiglottis away from the posterior pharyngeal wall and opens the path
• Suction any blood or secretions with the bronchoscope or a Yankauer sucker
• Sit patient up if currently supine
• Withdraw bronchoscope slightly and ensure that it is midline
• If necessary, withdraw bronchoscope and ensure that the tip is not covered with secretions.

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Difficulty advancing the ETT over the bronchoscope

The ETT can get "caught" when passing through the vocal cords, often on the right arytenoid.

Causes

• Left facing bevel results in the tip of the ETT impinging on the right arytenoid
• Deviation of the ETT from the bronchoscope due to the gap between the two
• When performing a nasal intubation, the ETT can become impinged on the epiglottis

Remedies

• Rotate the ETT 90° anticlockwise on the bronchoscope resulting in the bevel facing 6 o'clock, minimizing impingement on the right arytenoid
• Use a larger bronchoscope or smaller ETT to reduce the size discrepancy between the two
  

  Size 6 ETT used with adult bronchoscope results in less size discrepancy between ETT and bronchoscope.

• Use an ETT with a tapered tip (intubating LMA ETT, Parker Flex-tip® tube)
  
• Use a 'gap filler' between the bronchoscope and ETT (either a smaller, uncuffed ETT or the Aintree catheter)
  
• Ask the patient to inhale deeply and attempt to advance the ETT gently on peak inspiration
• Rotate ETT 90° CLOCKWISE – bevel up, if the site of impingement is the epiglottis
• Use a video laryngoscope (eg: GlideScope) in addition to the Bronchoscope to assist with visualizing where the ETT is impinging

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Tube-first approach vs. bronchoscope-first approach

Tube first: The ETT is inserted to the back of the nasal cavity, then the bronchoscope is passed through the ETT. The bronchoscope then acts as a 'bougie' allowing the ETT to be railroaded over it.

ETT First	Bronchoscope First
Advantages: Allows adequacy of nasal passage to be assessed – avoids problem of ETT not fitting into nasal cavity Minimizes time to advance ETT into the larynx Disadvantages: Blind insertion may produce bleeding, rendering bronchoscopy very difficult Blind passage into the nasopharynx may damage the mucosa	Advantages: Less risk of bleeding prior to entering trachea Disadvantages: ETT can be difficult to advance over bronchoscope Bronchoscope can pass through Murphy eye which will make advancement impossible

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Tips

• Always keep the target structure in the center of screen.
• Use small efficient movements of the bronchoscope.
• The operator should be comfortable. Arm fatigue is common if the scope is being held too high, so either lower the bed or stand on a step to allow the scope to hang freely. Hyperextension of the knees and low back strain can be reduced by elevating one leg on a stool.
• Ask the patient to take a deep breath and synchronize advancement of the ETT with vocal cord abduction.
• A small piece of tape applied to the ETT to keep it on the scope until released will prevent it from dropping.
• Warm the ETT with warm water to soften the tube and reduce fogging (especially when using a standard ETT).
• Usual depth for nasal intubation: 26 cm for women and 28 cm for men.

Tips to prevent fogging:

• Use an anti-fog solution on the tip of the bronchoscope.
• Apply 2L/min of oxygen through the working channel of the scope.

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