Efficacy of Intravenous Lidocaine for Postoperative Analgesia Following Laparoscopic Surgery: A Meta-Analysis

Intravenous (IV) lidocaine has analgesic and anti-inflammatory properties. This study aims to evaluate the efficacy of IV lidocaine in controlling postoperative pain following laparoscopic surgery. A meta-analysis of randomised controlled trials (RCTs) comparing IV lidocaine versus placebo/routine treatment for postoperative analgesia following laparoscopic surgery. The primary outcome was opiate requirement at 24 h. Secondary outcomes included cumulative opiate requirement, numerical pain scores (2, 12, 24, 48 h at rest and on movement), recovery indices (nausea and vomiting, length of stay, time until diet resumption, first flatus and bowel movement) and side effects (cardiac/neurological toxicity). Subgroup analyses were performed according to operation type and to compare IV lidocaine with intraperitoneal lidocaine. Fourteen RCTs with 742 patients were included. IV lidocaine was associated with a small but significant reduction in opiate requirement at 24 h compared with placebo/routine care. IV lidocaine was associated with reduced cumulative opiate requirement, reduced pain scores at rest at 2, 12 and 24 h, reduced nausea and vomiting and a shorter time until resumption of diet. The length of stay did not differ between groups. There was a low incidence of IV lidocaine-associated toxicity. In subgroup analyses, there was no difference between IV and intraperitoneal lidocaine in the measured outcomes. IV lidocaine has a multidimensional effect on the quality of recovery. IV lidocaine was associated with lower opiate requirements, reduced nausea and vomiting and a shorter time until resumption of diet. Whilst IV lidocaine appears safe, the optimal treatment regimen remains unknown. Statistical heterogeneity was high.