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

Abstract

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. 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. 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. 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.