Efficacy of intravenous lidocaine infusions for pain relief in children undergoing laparoscopic appendectomy: a randomized controlled trial
Authors: Kaszyński Maciej , Lewandowska Dorota , Sawicki Piotr , Wojcieszak Piotr , Pągowska-Klimek Izabela 
Published: January 2021

Abstract
Intravenous lidocaine, a potent local anesthetic with analgesic and anti-inflammatory properties, has been shown to be an effective adjunct that reduces intra- and postoperative opioid consumption and facilitates pain management in adults. While it shows promise for use in the pediatric population, limited evidence is available.

Objectives
To determine if general anesthesia with intraoperative intravenous lidocaine infusion versus general anesthesia without intravenous lidocaine infusion in children undergoing laparoscopic appendectomy decreased opioid requirements intra- and postoperatively.

Design
A single-center parallel single-masked randomized controlled study. A computer-generated blocked randomization list was used to allocate participants. The study was conducted between March 2019 and January 2020. Setting: Pediatric teaching hospital in Poland.

Participants
Seventy-four patients aged between 18 months and 18 years undergoing laparoscopic appendectomy. Seventy-one patients fulfilled the study requirements.

Intervention
Intravenous lidocaine bolus of 1.5 mg/kg over 5 min before induction of anesthesia followed by lidocaine infusion at 1.5 mg/kg/h intraoperatively. The infusion was discontinued before the patients’ transfer to the postanesthesia care unit (PACU).

Primary outcome measure
The primary outcome measure was total nalbuphine requirement in milligrams during the first 24 h after surgery.

Secondary outcome measures
The secondary outcome measures were intraoperative fentanyl consumption, intraoperative sevoflurane consumption, time to the first rescue analgesic request, incidence of postoperative nausea and vomiting during the first 24 h after surgery, frequency of side effects of lidocaine.

Results
Children (n = 74) aged 5–17 randomly allocated to receive intraoperative lidocaine infusion (n = 37) or no intervention (n = 37). Seventy-one were included in the analysis (35 in the study group and 36 in the control group). There was no difference in the cumulative dose of nalbuphine in the first 24 h after removal of the endotracheal tube between groups [median of 0.1061 (IQR: 0.0962–0.2222) mg/kg in the lidocaine group, compared to the control group median of 0.1325 (IQR: 0.0899–0.22020) mg/kg, p = 0.63].
Intraoperative fentanyl consumption was lower in the lidocaine group [median of 5.091 (IQR: 4.848–5.714) μg/kg] than in the control group [median of 5.969 (IQR: 5.000–6.748), p = 0.03].
Taking into account the additional doses administered based on clinical indications, the reduction in the requirement for fentanyl in the lidocaine group was even greater [median of 0.0 (IQR: 0.0–0.952) vs 0.99 (IQR: 0.0–1.809) μg/kg, p = 0.01].
No difference was observed in the sevoflurane consumption between the two groups [median of 32.5 ml (IQR 25.0–43.0) in the lidocaine group vs median of 35.0 ml (IQR: 23.5–46.0) in the control group, p = 0.56].
The time to first analgesic request in the lidocaine group was prolonged [median of 55 (IQR: 40–110) min in the lidocaine group vs median of 40.5 (IQR: 28–65) min in the control group, p = 0.05].
There was no difference in the frequency of PONV between the two groups (48.57% in the lidocaine group vs 61.11% in the control group, p = 0.29).
No lidocaine related incidence of anaphylaxis, systemic toxicity, circulatory disturbances or neurological impairment was reported, during anesthesia or postoperative period.

Conclusions
Intraoperative systemic lidocaine administration reduced the intraoperative requirement for opioids in children undergoing laparoscopic appendectomy. This effect was time limited, and hence did not affect opioid consumption in the first 24 h following discontinuation of lidocaine infusion.

Trial registration
NCT03886896.