Systemic Anti-Inflammatory Effects of Intravenous Lidocaine in Surgical Patients: A Systematic Review and Meta-Analysis

There has recently been increasing evidence that the use of perioperative intravenous lidocaine infusion possesses analgesic, opioid-sparing and anti-inflammatory effects in surgical patients. Although opioid-sparing and analgesic properties have been strongly supported, the anti-inflammatory features are not well established in elective surgery. Therefore, the aim of this systematic review is to examine the effect of perioperative intravenous lidocaine infusion on postoperative anti-inflammatory status in patients undergoing elective surgery. A search strategy was created to identify suitable randomised clinical trials (RCTs) in PubMed, Scopus, Web of Science and Clinicaltrials.gov databases until January 2023. RCTs that evaluated the effect of intravenous lidocaine infusion, compared with placebo, on adult patients who underwent elective surgery, in inflammatory markers response were included. Exclusion criteria consisted of paediatric patients, animal studies, non-RCT methodology, intervention without intravenous lidocaine, inadequate control group, duplicated samples, ongoing studies and lack of any relevant clinical outcome measures. The following inflammatory markers-interleukin (IL)-6, tumour necrosis factor (TNF)-alpha, IL-1RA, IL-8, IL-10, C-reactive protein (CRP), IL-1, IL-1 beta, interferon (IFN)-gamma, cortisol, IL-4, IL-17, high-mobility group protein B1 (HMGB1) and transforming growth factor (TGF)-beta-were evaluated as outcomes in this review. A total of 21 studies, including 1254 patients, were identified. Intravenous lidocaine infusion significantly reduced the change from IL-6 baseline levels at the end of surgery compared to a placebo (standardised mean difference [SMD]: 0.647, 95% confidence interval [CI]: 1.034 to 0.260). Usage of lidocaine was associated with a significant reduction in other postoperative pro-inflammatory markers, such as TNF-ff, IL-1RA, IL-8, IL-17, HMGB-1 and CRP. There was no significant difference in other markers, such as IL-10, IL-1 beta, IL-1, IFN-gamma, IL-4, TGF-beta and cortisol. This systematic review and meta-analysis provide support for the administration of perioperative intravenous lidocaine infusion as an anti-inflammatory strategy in elective surgery.