Intra- and postoperative very low dose intravenous ketamine infusion does not increase pain relief after major spine surgery in patients with preoperative narcotic analgesic intake.

Objective: This study aims to demonstrate the analgesic efficacy and opioid-sparing effect of low dose ketamine in patients with preoperative narcotic intake undergoing major spine surgery.

Design: The study used a prospective, randomized, double-blinded, and placebo-controlled clinical trial.

Settings And Patients: We evaluated the analgesic efficacy and safety of low dose IV ketamine infusion after major spine surgery in patients with preoperative narcotic analgesic intake.