Comparison of Ultrasound-guided Superior laryngeal nerve block with Ketamine gargle for prevention of sore throat after endotracheal intubation: A comparative, single-blinded randomized controlled trial.

Postoperative sore throat is frequently observed as a complication following extubation in patients undergoing general anesthesia with tracheal intubation. Most cases of post-operative sore throat usually resolve on their own, but it can also contribute to patient discomfort eventually extending hospitalization duration, and potentially impacting the mortality rates.  Superior laryngeal nerve blocks have already been proven to be effective in anesthetizing the larynx for airway manipulation and pain management. Moreover, the use of ultrasound-guided nerve blocks, known for their increased success rates due to visualization, is comparatively less time-consuming and associated with fewer complications. Ketamine gargle has been proven to control postoperative sore throats by blocking various pain-related receptors like N-methyl-D-aspartate receptors in peripheral nerves and exerting agonistic effects on opioid receptors within the mucosa of the oral and upper respiratory tract. We hypothesized superior laryngeal nerve block ameliorates the incidence and severity of postoperative sore throat better than ketamine gargle.  The primary objective of our study is to compare the incidence of postoperative sore throat (Grade≥2) after superior laryngeal nerve block and ketamine gargle in patients undergoing endotracheal intubation under general anesthesia.