The Nose
The use of topical anesthesia and decongestion in the nose is quite common before a laryngoscopy exam in order to make it comfortable for the patient to have the endoscope pass through the nose. This is often a mix of topical 4% lidocaine with a vasoconstrictor (oxymetazolone or phenylephrine). My pharmacist adds peppermint and stevia to improve the flavor and smell of the spray.
No anesthesia
Some people (not many) can be examined without topical anesthesia and prefer the light pressure over the taste of the anesthetic.
Avoid
- This combination is much better tolerated than Cetacaine (benzocaine with a banana flavor).
- 10% lidocaine typically has ethanol which tends to give the patient a strong burning sensation on the mucosa.
Gaggers
An oral topical anesthetic such as 4% lidocaine may also be sprayed onto the soft palate, posterior pharynx and base of tongue. Also, some individual’s gag is triggered in the nasopharynx, so after the initial decongestion, I place another spray deep into the nose that coats the nasopharynx.
If the examiner applies the spray anesthesia and waits for several minutes, the anesthesia becomes deeper and the decongestant opens the passage wider. Being in a hurry leads to discomfort. During my general exam of the ear, nose & throat, I pause to spray the nasal passage that is the widest open. Then, rather than insert the endoscope, I next perform my audio exam which takes 4-5 minutes to record the voice. This delay between placing the lidocaine and decongestant in the nose and later performing the endoscopic examination, makes it much more comfortable for the patient.
Pharynx & Larynx
Much less common is the application of lidocaine to the pharynx and larynx which permit an extraordinarily detailed examination of the larynx.
If close inspection of the larynx is anticipated, 4% topical lidocaine may be dripped onto the epiglottis and laryngeal introitus (the vocal cords). This is often done under direct visualization with the rigid or flexible endoscope to be sure the entire surface of the larynx is covered. Typically, the anesthetic is dripped into the larynx in several aliquots since the first drops cause significant gagging.
A curved cannula such as the Abraham cannula may be utilized to direct the anesthetic. It may be dripped without visualizing the larynx while listening for a laryngeal gargle, the gargle sound produced when liquid is sitting on the phonating vocal folds.
The Mucosal Atomization Device (MAD) is another option. It may be bent to direct the anesthetic onto the vocal cords.
Alternative methods include injecting into the trachea with a 25 gauge needle via the cricothyroid membrane. The needle is angled slightly downward and syringe aspirated to assure intraluminal placement. The ensuing cough blankets the larynx with topical anesthesia.
Patients with tracheostomy tubes may be anesthetized by placing a folded sponge over the tube and injecting through the sponge with a needle. Holding the hub of the syringe against the sponge not only spares the examiner a shower but directs the cough and anesthetic up through the larynx.
All of these methods allow for intimate inspection of the vocal cords and below the vocal cords.