Effect of ultrasound-guided internal superior laryngeal nerve block on sore throat after intubation by double-lumen bronchial tube for thoracoscopic surgery

Background Postoperative sore throat (POST) is a frequent complication following extubation. This study aimed to evaluate the safety and effectiveness of ultrasound (US)-guided bilateral internal superior laryngeal nerve (iSLN) block in reducing POST. Patients and methods A total of 64 adult patients undergoing thoracoscopic surgery with general anesthesia and double-lumen bronchial intubation were randomly allocated to either a control (standard care) or an iSLN block group (SLNB group). Results Blood pressure and heart rate measurements were comparable between the groups at baseline and postintubation ( P >0.05), but they decreased significantly in patients who received iSLN block after extubation ( P <0.05). The SLNB group also demonstrated significantly lower POST scores during the first 6 h ( P <0.05). Although differences were nonsignificant at 12 h, the SLNB group still had lower scores. Immediately postextubation, only three patients in the SLNB group had POST (score 1), while most in the control group had varying degrees of POST. At 2 h, 28 patients in the SLNB group were pain-free compared with 16 in the control group. At 4 and 6 h, POST continued to be lower in the SLNB group. By 12 h, 25 SLNB patients and 19 controls were pain-free. Postoperative complications were comparable between groups ( P >0.05). Conclusion US-guided iSLN block appears to be an effective technique for mitigating POST following double-lumen bronchial intubation in thoracoscopic procedures.