During awake fiberoptic intubation, which of the following techniques for superior laryngeal nerve block provides anesthesia to the epiglottis and aryepiglottic folds?

Explanation

## Superior Laryngeal Nerve Block Technique **Key Point:** The intraoral approach to superior laryngeal nerve (SLN) block—performed lateral to the greater horn of the hyoid bone—is the preferred technique for AFI because it reliably anesthetizes the epiglottis, aryepiglottic folds, and false vocal cords without risk of vascular puncture or tracheal injury. ### Anatomy of the Superior Laryngeal Nerve The SLN descends medial to the greater horn of the hyoid bone and divides into: - **Internal branch:** sensory to epiglottis, aryepiglottic folds, false vocal cords, and larynx above the true vocal cords - **External branch:** motor to the cricothyroid muscle (not blocked in routine AFI) ### Comparison of SLN Block Approaches | Approach | Landmark | Target | Advantages | Disadvantages | |----------|----------|--------|------------|---------------| | **Intraoral (lateral to greater horn)** | Greater horn of hyoid bone | SLN internal branch | Avoids vessels, easy landmark, safe | Requires patient cooperation | | **Transthyroid membrane** | Thyroid membrane midline | Recurrent laryngeal nerve (not SLN) | — | Blocks wrong nerve; risk of vascular injury | | **Transtracheal (below cricoid)** | Cricoid cartilage | Recurrent laryngeal nerve (not SLN) | — | Blocks wrong nerve; risk of tracheal puncture | | **Glossopharyngeal nerve block** | Stylohyoid ligament | CN IX (not SLN) | — | Blocks wrong nerve; not for AFI | **High-Yield:** The intraoral SLN block is performed with the patient's mouth open, palpating the greater horn of the hyoid bone intraorally, and injecting 2–3 mL of 1–2% lidocaine just lateral to the horn. This anesthetizes the superior laryngeal nerve as it descends medially. **Mnemonic:** **SLN-EPIGLOTTIS** — Superior Laryngeal Nerve blocks the Epiglottis, Aryepiglottic folds, and structures above the true vocal cords. The intraoral approach lateral to the greater horn is the safest route.