Intravenous Lidocaine Infusion in Lumbar Fusion Surgery

Lumbar fusion surgery is frequently associated with significant postoperative pain and often requires high doses of opioid analgesics during the perioperative period. Opioid administration may lead to several adverse effects including postoperative nausea and vomiting, sedation, respiratory depression, and delayed recovery. Therefore, multimodal analgesia strategies are increasingly used to improve postoperative pain control and reduce opioid requirements.

Intravenous lidocaine infusion has gained attention as an adjunct component of multimodal analgesia because of its analgesic, antihyperalgesic, and anti-inflammatory properties. Previous clinical studies have suggested that perioperative systemic lidocaine may reduce postoperative pain intensity, decrease opioid consumption, and improve recovery after surgery. However, evidence regarding its effectiveness in patients undergoing lumbar fusion surgery remains limited.

This prospective, randomized, placebo-controlled study will include adult patients aged 18-65 years with American Society of Anesthesiologists (ASA) physical status I-II who are scheduled for elective lumbar fusion surgery. Participants will be randomly allocated into two groups. Patients in the lidocaine group will receive an intravenous lidocaine bolus followed by continuous lidocaine infusion during surgery, whereas patients in the control group will receive an equivalent volume of normal saline infusion. The infusion will be maintained throughout the surgical procedure and discontinued at the end of surgery.

All patients will receive standardized general anesthesia and postoperative multimodal analgesia. Postoperative pain will be assessed using the Numerical Rating Scale (NRS). Rescue analgesia will be administered when clinically indicated.

The primary outcome is cumulative postoperative opioid consumption within the first 24 hours after surgery. Secondary outcomes include intraoperative opioid consumption, postoperative pain scores at predefined time points, time to first rescue analgesic requirement, postoperative nausea and vomiting incidence, quality of recovery measured by QoR-15, post-anesthesia care unit length of stay, time to mobilization, and hospital length of stay.

In addition, inflammatory and oxidative stress responses associated with surgery and lidocaine administration will be evaluated. Blood samples will be collected preoperatively and at 6 and 24 hours postoperatively to measure interleukin-6 (IL-6) levels and markers of thiol-disulfide homeostasis.

• Intraoperative remifentanil consumption [Срок оценки: From induction of anesthesia to the end of surgery]
• Postoperative pain intensity [Срок оценки: At arrival in the post-anesthesia care unit and at 2, 4, 6, 12, and 24 hours after surgery]
• Time to first rescue analgesic requirement [Срок оценки: Within the first 24 hours after surgery]
• Quality of recovery [Срок оценки: Preoperative baseline and 24 hours after surgery]
• Postoperative nausea and vomiting incidence [Срок оценки: 0-24 hours after surgery]
• Post-anesthesia care unit length of stay [Срок оценки: Immediate postoperative period (up to 24 hours after surgery)]
• Time to mobilization [Срок оценки: Up to 24 hours after surgery]
• Serum interleukin-6 (IL-6) levels [Срок оценки: Preoperatively and at 6 and 24 hours after surgery]