Procedure-specific effects of intravenous lidocaine in adult spine surgery: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND AND OBJECTIVES: Perioperative intravenous lidocaine infusion has been proposed as an opioid-sparing analgesic adjunct in spine surgery, but previous meta-analyses pooled heterogeneous procedures and may have obscured procedure-specific treatment effects. We evaluated the analgesic and opioid-sparing effects of perioperative intravenous lidocaine in adult spine surgery and whether efficacy differs by procedure type. METHODS: We searched PubMed, Embase, Web of Science, and the Cochrane Library from inception through June 2026 for randomized controlled trials comparing perioperative intravenous lidocaine infusion with placebo or standard care in adults undergoing spine surgery. The primary outcome was postoperative pain intensity at 24 hours. Secondary outcomes were opioid consumption, postoperative nausea and vomiting (PONV), and hospital length of stay (LOS). Random-effects meta-analyses, a post hoc subgroup analysis by procedure type, and meta-regression were performed. RESULTS: 10 randomized trials were included. Intravenous lidocaine reduced postoperative pain at 24 hours (9 trials, 655 patients; mean difference (MD), -0.83; 95% CI -1.36 to -0.30; p=0.002; I²=89%, 95% CI 81% to 93%; prediction interval, -2.69 to 1.02; moderate certainty) and opioid consumption (9 trials; MD, -11.64 mg intravenous morphine equivalents; 95% CI -16.14 to -7.14; p<0.001). In a post hoc exploratory analysis, the analgesic effect differed by procedure type (test for subgroup differences, p=0.005): the reduction was clinically meaningful after instrumented fusion or complex spine surgery (MD, -1.23; 95% CI -1.81 to -0.64), exceeding the minimal clinically important difference of 1.0 point, but minimal after decompression (MD, -0.20; 95% CI -0.61 to 0.21). Baseline pain severity explained approximately 53% of between-study heterogeneity, whereas lidocaine infusion rate did not modify the treatment effect (p=0.97). No significant effects were observed for PONV or LOS. CONCLUSIONS: There is moderate-certainty evidence that perioperative intravenous lidocaine reduces postoperative pain and opioid consumption after adult spine surgery. Its analgesic benefit appeared procedure-specific, with the greatest benefit after instrumented fusion and complex procedures; this difference emerged from a post hoc, exploratory analysis and should be regarded as hypothesis-generating.