Intra-operative lidocaine in the prevention of vomiting after elective tonsillectomy in children: A randomised controlled trial

BACKGROUND: Postoperative vomiting (POV) is a frequent complication of tonsillectomy in children. In adult patients undergoing abdominal surgeries, the use of intravenous lidocaine infusion can prevent POV. OBJECTIVE: To evaluate the anti-emetic effect of an intravenous lidocaine infusion used as an adjuvant to general anaesthesia, in children undergoing elective ear, nose and throat surgery. DESIGN: Double-blind, randomised, controlled study. SETTING: Hospital-based, single-centre study in Chile. PATIENTS: ASA I-II children, aged 2 to 12 years, scheduled for elective tonsillectomy. INTERVENTION: We standardised the induction and maintenance of anaesthesia. Patients were randomly allocated to lidocaine (1.5 mg kg intravenous lidocaine over 5 min followed by 2 mg kg h) or 0.9% saline (at the same rate and volume). Infusions were continued until the end of the surgery. MAIN OUTCOME MEASURES: Presence of at least one episode of vomiting, retching or both in the first 24 h postoperatively (POV). SECONDARY OUTCOMES: Plasma concentrations of lidocaine and postoperative pain. RESULTS: Ninety-two children were enrolled. Primary outcome data were available for 91. In the Lidocaine group, 28 of 46 patients (60.8%) experienced POV, compared with 37 of 45 patients (82.2%) in the Saline group [difference in proportions 21.3% (95% confidence interval (CI) 2.8 to 38.8), P = 0.024]. The intention-to-treat analysis showed that when we assumed that the patient in the Saline group lost to follow-up did not have POV, the difference in proportions decreased to 19.6% (95% CI, 0.9 to 37.2), with an unadjusted odds ratio of 0.38 (95% CI, 0.15 to 0.97, P = 0.044). The odds of having POV were 62% less likely in those patients receiving lidocaine compared with patients in the Saline group. The mean lidocaine plasma concentration was 3.91 μg ml (range: 0.87 to 4.88). CONCLUSION: Using an intravenous lidocaine infusion as an adjuvant to general anaesthesia decreased POV in children undergoing elective tonsillectomy. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01986309.