Ultrasound guided superior laryngeal nerve block as an adjuvant to generalanesthesia during endoscopic laryngeal surgery: A prospective, randomized, double-blind trial

Introduction: Blindly administered bilateral (B/L) superior laryngeal nerve (SLN) blocks, have been used to decrease the perioperative stress response of endoscopic laryngosurgeries. Use of ultrasound (USG) for giving these blocks is more likely to be successful, with fewer complications. We evaluated the efficacy of USG guided B/L SLN block in decreasing perioperative cough, sore-throat and hoarseness of voice. Material and methods: This study was conducted on forty patients undergoing endoscopic laryngosurgery under GA. Patients were randomized into two groups of 20 patients each. Patients in group C received GA, whereas those in group L received USG-guided SLN block bilaterally with 2.5 ml of 2% lignocaine, along with GA. Postoperative cough, sore throat and hoarseness of voice was measured at 30 min, 2 h, 4 h and 24 h following transfer to post-anesthesia care unit. Results: Patients receiving SLN block had significantly lower incidence of perioperative cough (20% in group L vs 90% in group C; p value - 0.0001) as well as sore throat (5% in group L vs 95% in group C; p value - 0.0001). In these patients, severity of hoarseness of voice was greater in the early postoperative period (100% in group L vs 70% in group C; p value - 0.027), while it decreased significantly at 24 h postoperatively(0.0% in group L vs 30% in group C; p value - 0.027). Conclusion: USG guided SLN block as an adjuvant to GA resulted in better recovery profile of the patients with significant reduction in postoperative cough, sore throat and hoarseness of voice.