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Local Anesthesia for Rigid Endoscopy

last modified on: Wed, 01/24/2018 - 13:03

Local Anesthesia for Rigid Endoscopy

return to:Head and Neck  ;Laryngology;Local Anesthesia in Otolaryngology

Laryngology 

  1. GENERAL CONSIDERATIONS
    1. The great majority of rigid endoscopy procedures done at the University of Iowa in the early 1980s were done under local anesthesia with sedation administered by the surgeon. These were usually performed in a clinic setting in a "minor room" or "surgicenter" without general anesthetic capabilities. This approach was taken for both practical as well as theoretical reasons. During that period, the availability of support for general anesthesia was limited. It was a much more effective use of resources to perform rigid endoscopy without involvement of the operating room or the anesthesia service.
    2. Theoretically, concern existed that placement of an endotracheal tube adjacent to an upper aerodigestive tract cancer would predispose the patient to recurrence. As a result, extirpative laryngeal cancer surgery was usually preceded by a tracheotomy to avoid placement of an endotracheal tube. Consistent with this theoretical concern, laryngeal cancers were approached with biopsies done through rigid endoscopy mandating an anesthetic approach that excluded endotracheal intubation. The majority of direct laryngoscopies and panendoscopies (including rigid thoracic esophagoscopy and rigid bronchoscopy) were done under local anesthesia with sedation.
    3. The theoretical concern about enhancing tumor spread by placement of an endotracheal tube past a laryngeal cancer has not been supported through clinical experience. This change in philosophy, coupled with greater access to general anesthesia, has now nearly eradicated the practice of rigid panendoscopy. Support for direct laryngoscopy under local anesthesia still persists. Teflon injection to treat unilateral laryngeal paralysis, which is a procedure now rarely used, is best effected under local anesthesia to assess the phonatory result as the Teflon is placed and manipulated. We no longer use this approach for Gelfoam or fat injection because the best phonatory result is not the immediate endpoint we seek through injection. In fact, with Gelfoam and fat, over-injection to develop a pressed voice in the immediate postoperative period is desirable to accommodate the expected reduction in bulk of the implant over time. As a result, we now perform most laryngeal fat and Gelfoam injections under general anesthesia employing either a small caliber endotracheal tube or an apnea technique.
  2. PREOPERATIVE PREPARATION
    1. History and Physical Exam
      1. Specifically address
        1. Cardiovascular status: expected stress induced by sympathomimetics
        2. Liver and renal disease: effects elimination of benzodiazepines and Demerol
    2. Consent
      1. Describe in detail the process whereby sedation and local anesthesia occurs; see individual endoscopy protocols for other considerations in obtaining consent
        1. Panendoscopy protocol
        2. Microdirect Laryngoscopy (Suspension Microlaryngoscopy or Direct Laryngoscopy) protocol
        3. Gelfoam injection protocol
        4. Laryngeal fat injection protocol
  3. NURSING CONSIDERATIONS
    1. Monitoring
      1. Blood pressure cuff (automated intermittent monitoring)
      2. ECG
      3. Pulse oximetry
      4. Supplemental oxygen in all cases
      5. Crash cart with intubation instrumentation in room
    2. Preoperative Medications
      1. Glycopyrrolate 0.1 to 0.2 mg IM on call to operating room (decreases secretions, vagolytic)
      2. Decadron 10 mg IV once IV started (reduces glottic edema)
  4. ANESTHESIA CONSIDERATIONS
    1. Sedation Medication (tailored to the case; one approach)
      1. Droperidol 1.25 mg IV (antiemetic and neuroleptic)
      2. Demerol and diazepam or midazolam in incremental IV doses (titrate to effect)
    2. Antidotes (drawn-up in syringe and readily available)
      1. Narcan 2 mg IV
      2. Mazicon 0.2 mg IV
    3. Local Anesthesia
      1. Calculate maximal total dose of cocaine (3 mg per kg) and lidocaine (3 to 7 mg per kg) that can be used in patient before starting. (Note: Since 1991, cocaine has rarely been used in our practice.)
        1. Gargle and swallow 10 cc Dyclone 0.5%; repeat two times (total of 30 cc) - historical, no longer available at UIHC
        2. Spray oropharynx and hypopharynx with cocaine 5% or, more often in current practice, pontocaine or 2% lidocaine
        3. Local anesthetic blocks: 1% lidocaine with 1:100,000 epinephrine
          1. Glossopharyngeal nerve blocks: 0.5 to 1.0 cc 1% lidocaine with 1:100,000 epinephrine is injected just posterior to posterior tonsillar pillar using curved tonsil needle (aspirate first, avoid carotid artery).
          2. Lateral base of tongue blocks (again, avoid carotid artery): This injection is usually not needed and should be used with restraint because of the rapid systemic uptake of the anesthetic through the vascular tongue.
          3. Sublabial block of frenulum of upper lip: endoscopies irritate this sensitive area; most important in edentulous patient.
          4. Pyriform sinus blocks: cotton-wrapped pyriform sinus forceps soaked in 5% cocaine (or pontocaine) is placed down along the lateral tongue base in pyriform sinuses and left in place for 3 to 5 minutes (blocks internal branch of superior laryngeal nerve).
          5. Superior laryngeal nerve (external branch) blocks: 1.5 cc of 1% lidocaine with 1:100,000 epinephrine is injected percutaneously adjacent the thyrohyoid membrane midway between the lateral aspect of the hyoid and superior cornu of thyroid cartilage (site of entry into thyrohyoid membrane of superior laryngeal nerve). Use noninjecting hand to palpate and laterally retract carotid artery.
        4. Topical anesthesia to supraglottic and glottic larynx: The patient (or assistant) holds the tip of the tongue forward with gauze sponges (4 x 4). The surgeon, employing a laryngeal mirror drip to image the larynx indirectly, uses a curved blunt-tipped needle to apply one or two drops of 2 to 4% lidocaine on the epiglottis, false vocal cords, and true vocal cords. Several applications may be required until cough is suppressed. The blunt needle can be used to retract the epiglottis anteriorly to improve exposure of the vocal cords. (Do not overdose, keep track of amounts used.)
          1. Test gag reflex with digital palpation.
  5. OPERATIVE PROCEDURE
    1. See
      1. Panendoscopy protocol
      2. Suspension microlaryngoscopy protocol
      3. Gelfoam injection protocol
      4. Laryngeal fat injection protocol
  6. POSTOPERATIVE CARE
    1. See
      1. Panendoscopy protocol
      2. Suspension microlaryngoscopy protocol
      3. Gelfoam injection protocol
      4. Laryngeal fat injection protocol
  7. SUGGESTED READING
    1. Bennet DR, et al. AMA Drug Evaluation. Chicago, Ill: American Medical Association; 1983.
    2. Gilman AG, Goodman LS, Gilman A. The Pharmacologic Basis of Therapeutics. New York, NY: McGraw Hill; 1985.
    3. Kraus EM. Endoscopy: A Scion of Sword Swallowing. Manuscript for Iowa Basic Science Course, 1981.
    4. Sataloff RT. Professional Voice: The Science and Art of Clinical Care. 2nd ed. In: Sataloff RT, ed. San Diego, Calif: Singular Publishing Group Inc; 1997:603-645.
    5. Thorek M. Diagnostic operations on the neck: laryngoscopy. In: Modern Surgical Technique: General Operating Considerations--Surgery of the Head and Neck and Plastic Surgery. Vol 1. Philadelphia, Pa: JB Lippincott Co; 1939:383-387.