Efficacy of intraoperative intravenous lidocaine for postoperative analgesia following bariatric surgery: a meta-analysis of randomized controlled studies

The impact of intravenous lidocaine in adults undergoing laparoscopic bariatric surgeries (LBS) remains unclear.This study aimed at investigating the effect of intravenous lidocaine on postoperative opioid consumption and recovery following LBS.Meta-analysis.We searched databases including MEDLINE, Embase, Google Scholar, and the Cochrane Library for randomized controlled trials that evaluated the use of intravenous lidocaine compared to placebo only prior to May 2021. The primary outcome was 24-hour postoperative opioid consumption, while secondary outcomes included pain score, quality of recovery (QOR)-40 score, length of hospital stay (LOS), and postoperative nausea/vomiting (PONV).Seven trials (496 participants) were included. Intraoperative intravenous lidocaine significantly reduced 24-hour equivalent morphine consumption (mean difference [MD]: -11.97 mg; 95% confidence interval [CI]: -23.12 to -.83), pain score at 1 to 3 hours (MD: -.77; 95% CI: -1.5 to -.04), and LOS (MD: -8.93 hr; 95% CI: -13.41 to -4.44) without positive impact on 24-hour pain score and PONV. There was also an increase in time to first opioid requirement (MD: 20.23 min; 95% CI: 11.76-28.7) and QOR-40 score (MD: 24.38; 95% CI: 5.57-43.18). However, sensitivity analysis demonstrated evidence supporting the beneficial effect of lidocaine only for time to first opioid requirement and QOR-40. The associations of intraoperative intravenous lidocaine with reductions in morphine consumption, pain score at 1 to 3 hours, and LOS after LBS were also weak.Intraoperative intravenous lidocaine during LBS prolonged time to first opioid requirement and improved quality of recovery postoperatively without 24-hour pain or nausea/vomiting benefits. Due to the small number of trials, larger studies are warranted to verify our findings.