A comparison between intravenous lidocaine and ketamine on acute and chronic pain after open nephrectomy: A prospective, double-blind, randomized, placebo-controlled study

Background: Recently, there has been increasing interest in the use of analgesic adjuncts such as intravenous (IV) ketamine and lidocaine. Objectives: To compare the effects of perioperative IV lidocaineand ketamine on morphine requirements, pain scores, quality of recovery, and chronic pain after open nephrectomy. Study Design: A prospective, randomized, placebo-controlled, double-blind trial. Settings: The study was conducted in Charles Nicolle University Hospital of Tunis. Methods: Sixty patients were randomly allocated to receive IV lidocaine: bolus of 1.5 mg/kg at the induction of anesthesia followed by infusion of 1 mg/kg/h intraoperatively and for 24 h postoperatively or ketamine: bolus of 0.15 mg/kg followed by infusion of 0.1 mg/kg/h intraoperatively and for 24 h postoperatively or an equal volume of saline (control group [CG]). Measurements: Morphine consumption, visual analog scale pain scores, time to the first passage of flatus and feces, postoperative nauseaand vomiting(PONV), 6-min walk distance (6MWD) at discharge, and the incidence of chronic neuropathic painusing the “ Neuropathic PainQuestionnaire” at 3 months. Results: Ketamine and lidocainereduced significantly morphine consumption (by about 33% and 42%, respectively) and pain scores compared with the CG ( P P P P Conclusion: Ketamine and lidocaineare safe and effective adjuvants to decrease opioid consumption and control early pain. We also suggest that lidocaineinfusion serves as an interesting alternative to improve the functional walking capacity and prevent chronic neuropathic painat 3 months after open nephrectomy.