Intravenous lidocaine infusion for acute postoperative pain: what the 2025-26 meta-analyses show

Perioperative intravenous lidocaine is a continuous infusion of a local anesthetic, started during surgery as a multimodal adjunct intended to reduce postoperative pain and enhance recovery ^[1]. The 2018 Cochrane review of 68 trials (4,525 participants) ruled out a clinically relevant pain reduction at 24 hours against placebo or no treatment ^[1]. The standardized mean difference was −0.14 (95% CI −0.25 to −0.04), and the authors assumed about 1 cm on a 10 cm scale is clinically meaningful ^[1]. Since 2025, procedure-specific meta-analyses have asked whether that conclusion holds by operation, by plasma concentration, and against epidural analgesia.

What changed in 2025 and 2026?

Five new reviews of randomized trials, plus one comparison with epidural analgesia, re-tested the infusion:

• Hysterectomy: a January 2025 review in the International Journal of Surgery pooled 9 placebo-controlled trials with 706 patients ^[2].
• Plasma concentration: a 2025 review in Pain Management related measured plasma lidocaine levels to outcomes in 15 trials with 898 patients ^[3].
• Colorectal surgery: an updated 2026 review in Surgical Endoscopy pooled 12 trials with 1,208 patients ^[4].
• Thoracoscopic surgery: two 2026 reviews, He and colleagues (15 trials, 1,103 patients) ^[5] and Liu and colleagues (16 trials, 1,045 patients) ^[6].
• Epidural comparison: a 2025 review in Anesthesiology Research and Practice analyzed 7 studies with 643 patients in major abdominal surgery ^[7].

What do the placebo-controlled reviews show?

In the 2025 hysterectomy review, lidocaine lowered resting pain scores at 2, 6, 8 and 24 hours and lowered 24-hour opioid requirement ^[2]. The same hysterectomy review found fewer cases of postoperative nausea and vomiting but no shorter time to first flatus ^[2]. In the 2026 colorectal review, which had moderate-to-high heterogeneity, pain at 24 hours was lower by a mean of 1.61 (95% CI −2.82 to −0.41), while opioid requirement did not differ ^[4]. The colorectal review also reported first flatus 7.08 hours sooner (95% CI −12.85 to −1.31), with no significant effect on ileus or length of stay ^[4].

In the 15-trial thoracoscopic review by He and colleagues, pain scores were lower at every time point to 48 hours, with the largest difference of 1.68 at 2 hours ^[5]. In the 16-trial review by Liu and colleagues, resting pain at 24 hours fell by 0.48 cm (95% CI −0.79 to −0.17) ^[6]. Liu and colleagues judged every pain reduction below their 1 cm clinical threshold, and prediction intervals, which describe where a future trial's result may fall, crossed no effect for all pain outcomes ^[6].

In the 2025 concentration review, lidocaine lowered recovery-room opioid requirement across 8 studies, and meta-regression linked higher plasma levels to larger reductions ^[3]. The 11 studies in that review reporting 24-hour outcomes found no significant difference in pain scores or opioid requirement ^[3].

How does intravenous lidocaine compare with epidural analgesia?

In the 2025 comparison in major abdominal surgery, epidural analgesia was associated with lower pain scores over the first 24 hours (standardized mean difference −0.23, 95% CI −0.40 to −0.06) ^[7]. That review found no pain difference at 48 or 72 hours and noted heterogeneity among its studies, one of which was observational ^[7]. The 2018 Cochrane review held only two trials (102 participants) comparing lidocaine with thoracic epidural analgesia and rated the effects unclear ^[1].

Where is the evidence uncertain?

The Cochrane authors found infusion rates ranging from 1 to 5 mg/kg/h, ending anywhere from the close of surgery to several days later ^[1]. Cochrane also noted that few trials systematically recorded adverse effects ^[1]. He and colleagues likewise judged the safety evidence insufficient because monitoring and reporting were inconsistent across thoracoscopic trials ^[5]. The colorectal authors called for further high-quality trials ^[4].

At the point of care: what to check

These details decide whether a review's result applies to your patient or protocol:

• Operation: the hysterectomy review found lower opioid requirement at 24 hours, while the colorectal review found no difference in opioid requirement ^[2][4].
• Time point: recovery-room versus 24-hour outcome, since the concentration review found lower recovery-room opioid requirement but no significant 24-hour difference ^[3].
• Clinical threshold: whether the pain difference reaches the 1 cm cut-off applied by Cochrane and by Liu and colleagues ^[1][6].
• Comparator: placebo trials and epidural comparisons answer different questions ^[7].
• Adverse-effect monitoring: whether the underlying trials recorded adverse effects systematically, which few trials in the Cochrane review did and which He and colleagues found inconsistent across thoracoscopic trials ^[1][5].