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

The dose-response of intravenous lidocaine in preventing postoperative vomiting (POV) in children remains unclear. This study investigated whether intravenous lidocaine dose-dependently decreased POV risk within 24 h postoperatively in children undergoing tonsillectomy (with or without adenoidectomy) without severe complications. Patients aged 3-12 years (American Society of Anesthesiologists grade I-II) scheduled for elective tonsillectomy (with or without adenoidectomy) were enroled 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 with sevoflurane. The incidence of POV 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. Postoperative analgesic rescues in groups A, B, C, and D were 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 were reported. Intravenous lidocaine has a dose-dependent effect on reducing the risk of POV in children undergoing tonsillectomy (with or without adenoidectomy) without serious adverse events.Trial registration: Chinese Clinical Trial Registry, ChiCTR2100053006.