Lidocaine and risk of postoperative vomiting in children undergoing tonsillectomy: a randomised clinical trial

Abstract The dose-response of intravenous lidocaine for preventing postoperative vomiting (POV) in children is unclear. This study investigated whether intravenous lidocaine dose-dependently decreases POV risk within 24 h postoperatively in children undergoing tonsillectomy (with/without adenoidectomy) without severe complications. Patients aged 3–12 years (American Society of Anesthesiologists grade I–II) scheduled for elective tonsillectomy (with/without adenoidectomy) were enrolled from December 2021 to March 2022. They were randomly grouped according to the lidocaine dose (A [0 mg kg⁻¹], B [1 mg kg⁻¹], C [1.5 mg kg⁻¹], and D [2 mg kg⁻¹]) and were administered the same induction protocol (sufentanil, propofol, and suxamethonium chloride). Anaesthesia was maintained using sevoflurane. POV incidence within 24 h postoperatively was 46%, 40%, 36%, and 20% in groups A, B, C, and D, respectively, with significant differences between groups D and A. That of postoperative analgesic rescue in groups A, B, C, and D was 62%, 36%, 34%, and 16%, respectively, with significant differences between groups D and B, C and A, and D and A. No severe adverse events occurred. Intravenous lidocaine (2 mg kg⁻¹) dose-dependently decreases POV risk without serious adverse events in children undergoing tonsillectomy (with/without adenoidectomy). Trial registration: Chinese Clinical Trial Registry, ChiCTR2100053006.