Therapeutic efficacy of intravenous lidocaine infusion compared with thoracic epidural analgesia in major abdominal surgery: a noninferiority randomised clinical trial.

Background: Open major abdominal surgery is one of the most risky surgical procedures for acute postoperative pain. Thoracic epidural analgesia (TEA) has been considered the standard analgesic approach. In different reports, lidocaine i.v. has been shown to have an analgesic efficacy comparable with TEA. We compared the analgesic efficacy of i.v. lidocaine with thoracic epidural analgesia using bupivacaine in patients undergoing major abdominal surgery.

Methods: In this noninferiority clinical trial, 210 patients were randomised to thoracic epidural bupivacaine with morphine or i.v. lidocaine. Dynamic pain at 24 h after surgery was measured using a numerical pain rating scale (NPR), and morphine consumption was also measured. A difference in i.v. the lidocaine-epidural bupivacaine NPR of ≤1 for dynamic pain was considered a noninferiority margin.

Results: The NPR for dynamic pain in the lidocaine group at 24 h was between 5.7 (1.8) and 5.2 (1.9) in the epidural group, with a difference of 0.53 (95% confidence interval 0.0-1.0). In the first 24 h, the average difference in morphine consumption was 1.8 mg between the i.v. lidocaine and epidural groups (95% confidence interval 1-3 mg). No differences were found in adverse events or complications associated with the procedures.

Conclusions: Intravenous lidocaine is noninferior to thoracic epidural analgesia for acute postoperative pain control in major abdomial surgery at 24 h postoperatively.

Clinical Trials Registration: NCT04017013.