Effect of intravenous lidocaine dose on pain upon awakening in pediatric tonsillectomy: A randomized trial

We investigated the potential of intravenous lidocaine to reduce pain on awakening in a dose- dependent manner and aimed to determine the median effective dose of lidocaine in 200 children aged 3-12 years (American Society of Anesthesiologists physical status I-II) who underwent elective tonsillectomy with or without adenoidectomy at Yichang Central Peoples Hospital. The patients were randomized into four dose groups (A-D: 0.0, 1.0, 1.5, and 2.0 mg/kg, respectively), and they underwent the same anesthetic induction and maintenance protocols. The primary outcome was pain on awakening, while secondary outcomes included pain scores at 1, 4, 12, and 24 h after awakening; incidences of laryngospasm, bronchospasm, or perioperative stridor; and time to extubation. Intraoperative cardiac events were classified as safety events. Our findings indicated that intravenous lidocaine dose-dependently reduced pain on awakening, with the median effective dose being 1.75 mg/kg. Significant differences were observed between groups A and D (P [≤] 0.001). No incidents of laryngospasm, bronchospasm, or perioperative stridor were observed. Furthermore, there were significant between-group differences in time to extubation (P [≤] 0.05). In conclusion, our study demonstrated that lidocaine dose-dependently reduced pain on awakening in children undergoing tonsillectomy with or without adenoidectomy, with no severe adverse events.