Intraoperative systemic infusion of lidocaine reduces postoperative pain after lumbar surgery: a double-blinded, randomized, placebo-controlled clinical trial.

BACKGROUND CONTEXT: Analgesic effect of lidocaine infusion on postoperative pain.

PURPOSE: The aim of this study was to evaluate the analgesic effect of lidocaine infusion on postoperative pain after lumbar microdiscectomy.

STUDY DESIGN: This study used a prospective, randomized, double-blinded, and placebo-controlled clinical trial.

PATIENT SAMPLE: Fifty-one patients participated in this randomized, double-blinded study.

OUTCOME MEASURES: The primary outcome was the visual analog scale (VAS) (0-100 mm) pain score at 4 hours after surgery. The secondary outcomes were the VAS pain score at 2, 8, 12, 24, and 48 hours after surgery, the frequency with which patients pushed the button (FPB) of the patient-controlled analgesia system, and the fentanyl consumption at 2, 4, 8, 12, 24, and 48 hours after surgery. Other outcomes were satisfaction scores regarding pain control and the overall recovery process, incidence of postoperative nausea and vomiting (PONV), and length of hospital stay (HS).

METHODS: Preoperatively and throughout the surgery, Group L received intravenous lidocaine infusion (a 1.5-mg/kg bolus followed by a 2-mg/kg/h infusion until the end of the surgical procedure) and Group C received normal saline infusion as a placebo.

RESULTS: The VAS scores and fentanyl consumption were significantly lower in Group L compared with Group C except at 48 h after surgery (p<.05). Total fentanyl consumption, total FPB, length of HS, and satisfaction scores were also significantly lower in Group L compared with Group C (p<.05).

CONCLUSIONS: Intraoperative systemic infusion of lidocaine decreases pain perception during microdiscectomy, thus reducing the consumption of opioid and the severity of postoperative pain. This effect contributes to reduce the length of HS.