1. 2024;27;E317-E326A Systematic Review and Meta-analysis of the Analgesic Effects of Lidocaine Administered Intravenously or Intraperitoneally Post-Abdominal Surgery
   Systematic Review
   Yanmei Bi, MD, Min Diao, MD, Yunkai Tao, MD, Hao Li, PhD, and Xuemei Lin, PhD.

BACKGROUND: Reducing postoperative pain is still a tremendous challenge for perioperative clinicians. Lidocaine is a local anesthetic that belongs to the amide class and has anti-inflammatory, anti-hyperalgesic, and analgesic effects. Extensive research has been conducted to determine the optimal route for its administration.

OBJECTIVE: To compare the efficacy of perioperative intravenous lidocaine with that of intraperitoneal lidocaine on postoperative analgesia in patients undergoing abdominal surgery.

STUDY DESIGN: EMBASE, PubMed, and The Cochrane Library were searched for randomized controlled trials published through December 2022 that compared patients receiving perioperative intravenous lidocaine with those receiving intraperitoneal lidocaine. The primary outcome measures included the pain score, as evaluated by the Visual Analog Scale, and opioid analgesia requirements. The secondary outcome measures were hospitalization length, gastrointestinal function recovery, etc. The data were acquired and recorded in electronic spreadsheets that had been designed for this purpose.

METHODS: This systematic review’s design was based on the Cochrane Handbook for Systematic Reviews of Interventions and was reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) method was used to examine the certainty of the evidence. Furthermore, we examined the dependability of the calculated (favorable) treatment effects through considerations of information size and modified significance thresholds (trial sequential analysis).

RESULTS: Seven trials including 478 patients were included. Our meta-analysis demonstrates that compared with intravenous lidocaine, patients who received intraperitoneal lidocaine had lower pain scores at 4 hours (mean difference [MD] 1.40; 95% CI, 0.22 to 2.59); 12 hours (MD 0.18; 95% CI, 0.06 to 0.30); and 24 hours (MD -0.12; 95% CI -0.40 to 0.17) postsurgery. However, no obvious difference in opioid consumption (P > 0.05) was found. In addition, the intraperitoneal lidocaine group had a longer postsurgery hospital stay than the intravenous lidocaine group (95%CI, -0.17 to -0.00; I2 = 0%). Intravenous lidocaine was more beneficial for achieving gastrointestinal return than intraperitoneal lidocaine (95% CI, -0.26 to -0.10; I2 = 2%).

LIMITATIONS: The sample size of enrolled RCTs was small, which could potentially result in an overestimation or underestimation of the treatment effect in the collected data. There was high heterogeneity among the studies.

CONCLUSION: This meta-analysis suggests that post-abdominal surgery intraperitoneal lidocaine administration has a better analgesic effect than intravenous lidocaine, with a lower pain score. However, intravenous lidocaine is more beneficial for gastrointestinal recovery after abdominal surgery.

KEY WORDS: Lidocaine, abdominal surgery, intravenous, intraperitoneal, postoperative pain, opioid consumption, meta-analysis, trial sequential analysis