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Effect of modified anterior approach for ultrasound-guided superior laryngeal nerve block on sore throat after tonsillectomy in adults: study protocol for a double-blind randomised controlled trial

Li H, Zhou R, Hua Y, Zheng J, Chen G, Zhu T

BMJ open, 2026

40 participants

Abstract

Introduction: Postoperative sore throat (POST), a common complication following tonsillectomy, significantly impairs patient recovery through persistent pain and dysphagia. The internal branch of superior laryngeal nerve block (iSLNB) can effectively alleviate POST. Specifically, the ultrasound (US)-guided modified anterior approach for iSLNB offers anatomical precision and reduced invasiveness compared with traditional approaches. This study aims to determine whether the US-guided modified anterior approach for iSLNB can relieve POST in adults after tonsillectomy.

Methods and analysis: A total of 40 patients scheduled for elective tonsillectomy under general anaesthesia will be randomly allocated to either the nerve block group (US-guided modified anterior iSLNB group) or the blank control group (only US scanning). Following the induction of general anaesthesia, the corresponding interventions will be performed, followed by postoperative pain assessment. The main outcome will be the POST intensity during swallowing at 24 hours after surgery. Secondary outcomes will consist of (a) the level of POST at rest at the same 24-hour postoperative time point; pain intensity measurements at rest and while swallowing recorded at 1 hour, 6 hours, 48 hours and on postoperative day 7; (b) the incidence of total pain at 24 hours postoperatively; (c) the time until the first administration of rescue analgesia and the cumulative dosage of rescue analgesic drugs consumed; (d) pain…

How strong is the evidence?

Evidence Hub reads this as a randomized trial, done in people. Its evidence level is 2 of 5 (High · randomized trial). Randomized trials of a reasonable size are the strongest single-study design. Reported size: 40 participants or records.

How the five levels of evidence work. The level is assigned automatically from the abstract and can be wrong, so check the paper.

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