Comparison between landmark and ultrasound-guided percutaneous peristyloid glossopharyngeal nerve block for post-tonsillectomy pain relief in children: a randomized controlled clinical trial

Background Glossopharyngeal nerve (GPN) block is a useful treatment option for acute post-tonsillectomy pain. This study aimed to assess safety and efficacy of the landmark (LM) technique versus the ultrasound (US)-guided technique for GPN block in children undergoing tonsillectomy. Methods This double-blinded, parallel-group, randomized trial enrolled 54 children of both genders who were American Society of Anesthesiologists physical status grade I-II and were scheduled for tonsillectomy under general anesthesia. All patients underwent percutaneous peristyloid GPN block. In the LM group, 27 patients were managed by insertion of the needle at midpoint of the line between the mastoid process and angle of the mandible. In the US group, 27 patients were managed with the US-guided technique to locate the styloid process. The outcomes were time to first analgesic requirement, pain in rest and during swallowing, easiness of the technique, time required for the technique performance, recovery time from anesthesia, and anesthetist, surgeon, parent, and staff satisfaction. Results The post-tonsillectomy pain score during rest and swallowing, rescue analgesic request, recovery time from general anesthesia, anesthetist', surgeon', staff nurses', and parents' satisfactions were comparable between the LM technique and US-guided percutaneous peristyloid GPN block (all p > 0.05). However, the LM technique was significantly easier and required shorter duration than the US-guided technique (p < 0.05). Conclusion In tonsillectomy surgery, both the LM technique and the percutaneous peristyloid US-guided GPN block were safe and effective in reducing postoperative pain. Furthermore, the LM technique was easier and had shorter duration to perform than the US-guided technique.