Ultrasound-guided distal glossopharyngeal nerve block for post-tonsillectomy pain relief in adults: a prospective randomized study.

BACKGROUND: We aimed to evaluate the safety and efficacy of the novel distal approach of ultrasound (US)-guided glossopharyngeal nerve (GPN) block at the pharyngeal wall for enhancing the quality of analgesia in patients undergoing tonsillectomy.

METHODS: Fifty patients, both male and female, between the ages of 21 and 65, categorized as ASA I-II by the American Society of Anesthesiologists (ASA) and who were scheduled for tonsillectomy, were enrolled in the study. Patients were randomly assigned to receive general anesthesia with either bilateral US-guided distal GPN block (GPN group) or no block (control group). The time for first request of analgesics, postoperative pain scores, the total amount of rescue analgesic medication consumed within a 24-hour period, and the occurrence of any adverse events were all noted.

RESULTS: The onset of first analgesic request was significantly prolonged in GPN group than the control group (P=0.013). Pain scores at 30 min, 2 and 6 hours postoperative were found to be significantly lower in GPN group than the control group both at rest (adjusted P=0.005, 0.000, and 0.020 respectively) and during swallowing (adjusted P=0.002, 0.000, and 0.015 respectively), with significantly less morphine consumption at 24 hours postoperative in GPN group compared with the control group (P=0.002). No significant postoperative block-related complications were observed.

CONCLUSIONS: In patients having tonsillectomy, pre-emptive application of US-guided distal GPN block at the pharyngeal wall enhanced the quality of analgesia and decreased the need for rescue analgesics with no major adverse effects.