Logo for University of Iowa Health Care This logo represents the University of Iowa Health Care
Mastoid Dressing Supplies (Ear Surgery Covering Materials)Click Here

Difficulty airway management- adult awake fiberoptic intubation - considerations

last modified on: Mon, 11/20/2023 - 10:22

See also:  Adult Airway in the Operating RoomPositioning for awake sitting nasotracheal intubationSuperior Laryngeal Nerve Blocks Instruction VideoDifficult Airway - General Considerations

Considerations

  • Transnasal vs transoral route – A brief discussion:
    • The transnasal route provides a very direct path to the larynx for the scope and ETT after the turn at the nasopharynx is made; the tube is directed toward the trachea while following this route (see: Examination of the subglottis with transnasal laryngoscopy); the nasal anatomy should be assessed - and may be potentially modified (such as outfracturing the inferior turbinate if necessary).
    • The transoral route is used by anesthesia for elective intubations in the OR which does require additional topical anesthesia to the oropharynx and larynx often supplemented by sedation that can be contraindicated in the face of morbidly obese patients with sleep apnea. In our experience, the awke intubation via the oral route may be less comfortable and more stimulating than the nasal route if the nose is prepared appropriately. To guide the bronchoscope around the curve at the base of tongue an extremely sharp turn is required at the oropharynx, and it is not as simple to find the larynx, as it is usually directly at the level of the turn.
    • In general, our bias has been for awake unsedated fiberoptic intubation is generally to recommend the transnasal route.
  • Size of the ETT (If you are doing transnasal, consider the size of your nasal airway); a smaller tube such as a 5 or 6 MLT is generally recommended
  • Size of your flexible bronchoscope is a consideration - and tested before starting to ensure it fits well within the endotracheal tube (especially important in peds; if using adult size ETT, any bronch should work) (our preferred scope with suction and good distal chip illumination:)

Equipment

Ask for these items immediately: Bronchoscope, Respiratory therapy with a vent, ER physician with drugs for sedation, 4% lidocaine from pharmacy; and then focus on getting your bronchoscope set up, while other personnel get organized

  • Flexible bronchoscope (Make sure to check the suction, light and injection port. Make sure everything is working and connected before starting.)
  • Surgilube or silicone spray so that ETT slides over bronch easily
  • ETT
  • Several 5cc syringe with slip tip connector to fit the injector port (can make a leur-lock into a slip tip by cutting off the thread portion)
  • Two suction setups, one with a Yankaeur, the other for the bronchoscope

Topical Anesthesia

(update see also recommended: Superior Laryngeal Nerve Blocks Instruction Video)

  • 4% lidocaine -put 1.5 cc in several syringes; Put several cc’s of air in as a chaser so you can push it through the length of the scope when you inject (note that lidocaine/phenylephrine spray to the nose and superior laryngeal nerve block may be all that is required; supplementing this approach with dripping topical lidocaine into the trach may diminish the cough attending placement of the tube)

Keep track of the quantity of 4% that you use. see: Maximum Recommended Doses and Duration of Local Anesthetics

  • If transoral: consider lidocaine paste on a tongue depressor, Hurricane spray (can only use a ½ second spray pulse, or else risk methemoglobinemia)
  • If transnasal: consider outfracture of turbinate - alternatively sequential dilation with lidocaine jelly in the nostril, use on the nasal trumpets

-Afrin + lidocaine, or Phenylephrine + lidocaine spray

-Nebulized lidocaine – 2-3cc of 4% lidocaine nebulized by a face mask

  • Place 1.5cc 4% lidocaine in a syringe with a catheter tip placed through the mouth and towards the oropharynx – have patient take a deep breath and spray while inhaling to cause the spray to enter the larynx

Procedure

  1. Perform any topicalization you have planned (nose, oropharynx, larynx)
  2. Spray afrin and lidocaine in the nose, dilate the nasal passage with nasal trumpets (28-34 French)
  3. See optimal positioning: Positioning for awake sitting nasotracheal intubation alternatively: Elevate the head of bed to reduce obstruction – have the patient almost sitting upright, change height of bed so nose is even with your shoulder
  4. Streamline the ETT: over deflate the cuff and slide it over your bronch up to the hub and lube the bronchoscope so the tube passes easily
  5. Transnasal
    1. Identify the best side of the nose to approach
    2. Can advance in one of two ways
      1. Some support preloading the endotracheal tube in the nasal cavity until resistance is felt (which is likely the nasopharynx). Then advance your bronch through the tube (important, follow the white lines on the ETT to the tip so you do not go through the Murphy eye during advancement). Can advance your tube with your bronch until you are just above the larynx. The drawback to doing this is a) potentially causing bleeding in the nasal cavity or nasopharynx before being able to visualize the larynx, and b) starting with the most painful part first, which causes the patient to become uncooperative.
      2. A reliable approach is to hub the ETT on the scope, and advance the bronch through the nasal cavity first, identify the larynx and pass all the way to the carina, before advancing the ETT into the nose; at that point you do it fast and all the way to the hub, which causes pain, but also completes the intubation
  6. Transoral
    1. Jaw thrust or pull the tongue to help improve your view
    2. Consider using an Ovassapian airway
    3. Once you visualize the true vocal cords with either approach, and are positioned about 2cm above the anterior commissure, spray 1 cc of 4% on the cords with the syringes you have prepared (with air chaser). You should see the fluid discharge from the tip. If there is coughing, spray a little more. Wait 30 seconds for it to work.
    4. Aim for the anterior commissure as you advance the scope past the cords (if the patient coughs and the larynx elevates, you will still slide into the trachea; if you aim posterior, you are likely to pass into the esophagus if the larynx elevates and moves anterior); Advance the bronchoscope rapidly down the trachea until you are just above the carina
    5. While seeing the carina, advance the tube (if transoral, break apart the Ovassapian airway). Sometimes the tube sticks at the level of the arytenoids; if so, rotate it 90 degrees so that it rolls off the arytenoid.
    6. Once you have adequately advanced the tube, pull back the bronchoscope and identify the tip of the ETT. Confirm bilateral breath sounds (can sometimes confuse the bifurcation of the bronchi with carina!). Use a CO2 indicator. Ventilate. Make sure the tube measurement at the teeth or nose is reasonable. Can get a CXR if there is any doubt.
    7. Have ER physician or anesthesia administer sedation drugs. A brief word: in most emergency situations, it is may be problematic to give any pre-sedation (even benzodiazepines); it causes a patient to relax, and often their adrenergic state is helpful to maintaining their airway or respiratory effort. Communicate with anesthesia regarding your concerns about the airway - may consider hold on administering any sedation until after the airway is secured – many patients tolerate a transnasal fiberoptic intubation quite well with only topical anesthesia.