Treatment of Postoperative Sore Throat with Ultrasound-guided Internal Branch of Superior Laryngeal Nerve Block: A Report of Three Cases

Abstract

Background Postoperative sore throat (POST) is a common problem following extubation after general anesthesia (GA). Severe POST leads to dissatisfaction and discomfort for a longer period, are resistant to current medical treatment. Method POST was measured after extubation 30 min, 2 h, 4 h, 6 h and 24 h. We present three cases of severe hoarseness or aphonia after extubation. A 8–13 MHz high frequency linear probe ultrasound transducer was used to visualize the internal branch of superior laryngeal nerve block (ibSLNB), which through thyrohyoid membrane between hyoid bone and thyroid cartilage. By out-plane technique, 2 mL of 2% lidocaine was injected around ibSLNB on each side. Result The three cases with severe POST was successfully treated with ultrasound-guided bilateral ibSLNB within 5 min, and their voice rapidly became louder and clearer. POST was significantly disappeared for 2-4 hours, and subsequently the resurfaced throat pain was milder, only needed or no anti-inflammatory drugs. No choking or aspiration was observed after ibSLNB when they were asked to swallow 20 ml of liquid 2 h post-operation. No postoperative laryngospasm or vomiting were recorded. Conclusion The ultrasound-guided bilateral ibSLNB may be a valid alternative to drugs, especially in serious acute POST after extubation.