The Efficacy of Ultrasound-Guided Superior Laryngeal Nerve Block as an Adjuvant to General Anesthesia during Suspension Laryngoscopy Vocal Cord Polypectomy

Abstract

Background. In the current study, we assessed the effect of the ultrasound-guided internal branch of the upper laryngeal nerve (USG-guided iSLN) block combined with general anesthesia on perioperative sore throat (POST), cough, hoarseness of voice, intraoperative hemodynamic changes, and the quality of early recovery for the patients undergoing suspension laryngoscopy vocal cord polypectomy (SLVCP). Methods. This was a randomized controlled trail. Eighty patients, aged from 18 to 70 years old, ASA I ∼ II, scheduled for polypectomy of the vocal cord by using a laryngoscope, were randomized into 2 groups (n = 40 each) using a random number table. Patients in group C received general anesthesia (GA), whereas those in group S received USG-guided iSLN block bilaterally (37.5 mg of 0.375% ropivacaine, 5 ml each side) combined with GA. The primary outcome was the quality of patients’ recovery using the Quality of Recovery Questionnaire (QoR-9). The secondary outcomes were postoperative cough, sore throat, hoarseness of voice, and hemodynamic changes in both groups at corresponding time points. The adverse reactions such as postoperative chocking, or aspiration, and dyspnea was recorded as well. Results. The QoR-9 scores of patients in group C were lower than those of group S at time points of D1∼D2 ( $P<0.05$ ). Patients in group S had a significantly lower incidence of perioperative cough than those in group C in the early postoperative period (1 hour after extubation) ( $P<0.05$ ), the scores of sore throat were lower in group S than those in group C ( $P<0.05$ ), the incidence of postoperative hoarseness was increased in group S than that in group C at the time points of 30 min, 2 h, and 4 h after extubation ( $P<0.05$ ); however, the incidence of postoperative hoarseness was decreased in group S than that in group C at the time point of 24 h after extubation ( $P<0.05$ ). MAP and HR of group S was lower than those of group C at time points of T1∼T4 ( $P<0.05$ ). No serious adverse events were observed in both groups. Conclusion. The study found that the application of ultrasound guided superior laryngeal nerve block combined with general anesthesia for the patients undergoing SLVCP could effectively promote the quality of early recovery. Clinical trial registration: This trial is registered with NCT05309174. The date of registration: March 12th 2021.Trial registry name: The Study of Bilateral Upper Laryngeal Nerve Block for Supporting the Removal of Vocal Cord Polyps Under Laryngoscopy.