Effects of systemic lidocaine versus magnesium administration on postoperative functional recovery and chronic pain in patients undergoing breast cancer surgery: A prospective, randomized, double-blind, comparative clinical trial

INTRODUCTION: We aimed to compare the effects of intraoperative lidocaine and magnesium on postoperative functional recovery and chronic pain after mastectomy due to breast cancer. Systemic lidocaine and magnesium reduce pain hypersensitivity to surgical stimuli; however, their effects after mastectomy have not been evaluated clearly. METHODS: In this prospective, double-blind, clinical trial, 126 female patients undergoing mastectomy were randomly assigned to lidocaine (L), magnesium (M), and control (C) groups. Lidocaine and magnesium were administered at 2 mg/kg and 20 mg/kg for 15 minutes immediately after induction, followed by infusions of 2 mg/kg/h and 20 mg/kg/h, respectively. The control group received the same volume of saline. Patient characteristics, perioperative parameters, and postoperative recovery profiles, including the Quality of Recovery 40 (QoR-40) survey, pain scales, length of hospital stay, and the short-form McGill pain questionnaire (SF-MPQ) at postoperative 1 month and 3 months were evaluated. RESULTS: The global QoR-40 scores on postoperative day 1 were significantly higher in group L than in group C (P = 0.003). Moreover, in sub-scores of the QoR-40 dimensions, emotional state and pain scores were significantly higher in group L than those in groups M and C (P = 0.027 and 0.023, respectively). At postoperative 3 months, SF-MPQ and SF-MPQ-sensitive scores were significantly lower in group L than in group C (P = 0.046 and 0.036, respectively). CONCLUSIONS: Intraoperative infusion of lidocaine improved the quality of recovery and attenuated the intensity of chronic pain in patients undergoing breast cancer surgery.