The impact of peri-operative intravenous lidocaine on postoperative outcome after elective colorectal surgery A meta-analysis of randomised controlled trials

BACKGROUND There has recently been increasing interest in the use of peri-operative intravenous lidocaine (IVL) due to its analgesic, anti-inflammatory and opioid-sparing effects. However, these potential benefits are not well established in elective colorectal surgery. OBJECTIVES To examine the effect of peri-operative IVL infusion on postoperative outcome in patients undergoing elective colorectal surgery. DESIGN A meta-analysis of randomised controlled trials (RCTs) comparing peri-operative IVL with placebo infusion in elective colorectal surgery. The primary outcome measure was postoperative pain scores up to 48 h. The secondary outcome measures included time to return of gastrointestinal function, postoperative morphine requirement, anastomotic leak, local anaesthetic toxicity and hospital length of stay. DATA SOURCES PubMed, Scopus and the Cochrane Library databases were searched on 5 November 2018. ELIGIBILITY CRITERIA Studies were included if they were RCTs evaluating the role of peri-operative IVL vs. placebo in adult patients undergoing elective colorectal surgery. Exclusion criteria were paediatric patients, noncolorectal or emergency procedures, non-RCT methodology or lack of relevant outcome measures. RESULTS A total of 10 studies were included (n = 508 patients; 265 who had undergone IVL infusion, 243 who had undergone placebo infusion). IVL infusion was associated with a significant reduction in time to defecation (mean difference -12.06 h, 95% CI -17.83 to -6.29,I-2 = 93%,P = 0.0001), hospital length of stay (mean difference -0.76 days, 95% CI -1.32 to -0.19,I-2 = 45%,P = 0.009) and postoperative pain scores at early time points, although this difference does not meet the threshold for a clinically relevant difference. There was no difference in time to pass flatus (mean difference -5.33 h, 95% CI -11.53 to 0.88,I-2 = 90%,P = 0.09), nor in rates of surgical site infection or anastomotic leakage. CONCLUSION This meta-analysis provides some support for the administration of peri-operative IVL infusion in elective colorectal surgery. However, further evidence is necessary to fully elucidate its potential benefits in light of the high levels of study heterogeneity and mixed quality of methodology.