Perioperative intravenous lidocaine for gastrointestinal recovery, opioid use, and safety after adult spine surgery: a systematic review and meta-analysis of randomized controlled trials

Background Adult spine surgery is associated with postoperative pain, opioid exposure, delayed bowel recovery, and variable discharge readiness. Intravenous lidocaine has been proposed as an adjunct for its analgesic, anti-inflammatory, and potential opioid-sparing effects, but its recovery-specific effects in spine surgery remain uncertain. Methods We conducted a systematic review and meta-analysis of randomized controlled trials in adults undergoing spine surgery. Eleven databases and registries were searched from inception to July 2026 without language restrictions. Two reviewers independently screened records, assessed full texts, and evaluated outcome-specific risk of bias using RoB 2. Compatible continuous outcomes were synthesized as mean differences using random-effects models with modified Knapp-Hartung confidence intervals. GRADE judgements were independently assessed and resolved by consensus. Results The searches identified 2,372 records; 1,668 remained after deduplication, and 17 eligible reports were treated as 17 trial cohorts. Four trials with 272 analyzed participants contributed to time to first flatus (MD, -4.65 h; modified Knapp-Hartung 95% CI, -7.22 to -2.08; low-certainty evidence). Three trials required median/IQR conversion. Wan and quantile-estimation analyses produced similar estimates; excluding converted or high-risk results each left one trial. Estimates were inconclusive for 0–24 h intravenous PCIA sufentanil consumption (2 trials, 347 participants; MD, -13.37 micrograms; 95% CI, -75.41 to 48.67; very-low-certainty evidence) and resting pain at 48 h (3 trials, 211 participants; MD, -0.53 points; 95% CI, -1.31 to 0.26; low-certainty evidence). Two single-trial QoR-15 estimates favoured lidocaine at 24 and 48 h, but certainty was low. Safety ascertainment was incomplete and adverse-event-related withdrawals were reported. Conclusions Low-certainty evidence suggests that perioperative intravenous lidocaine may shorten the time to first reported flatus after adult spine surgery, although the magnitude and patient importance of this effect remain uncertain. Evidence was insufficient to establish consistent opioid-sparing, analgesic, or broader recovery effects, and safety remains uncertain. These findings identify a possible gastrointestinal-recovery signal but do not support routine unselected use. Trial registration PROSPERO: CRD420261437127. Clinical trial number not applicable.