An estimation for an appropriate end time for an intraoperative intravenous lidocaine infusion in bowel surgery: a comparative meta-analysis

Study objective: There exists no commonly accepted regimen for an intravenous lidocaine infusion (IVLI). This study aims to determine an appropriate end time for an IVLI during bowel surgery.

Design: A systematic search for randomized controlled trials assessing IVLI for bowel surgery was conducted using Ovid MEDLINE, EMBASE, CINAHL, Cochrane CENTRAL, Google Scholar, hand-searching references, and grey literature. Data were pooled for studies that stopped IVLI ≤60 minutes (intraoperative IVLI) after skin closure and where IVLI continued >60 minutes after surgery (postoperative continued IVLI). Quantitative analysis was done using the random-effects model.

Main results: Seven studies (n = 362) were identified after the systematic search. Three studies (n = 160) and 4 studies (n = 202) used an intraoperative and postoperative continued IVLI, respectively. An intraoperative IVLI significantly reduced pain scores at rest for 48 hours (standardized mean difference on a 0-10 scale, -1.24; 95% confidence interval, -1.93 to -0.56) and 72 hours (standardized mean difference, -1.12; 95% confidence interval, -1.79 to -0.44) compared with postoperative IVLI (test for interaction: P < .001 and P = .003, respectively). Although intraoperative IVLI reduced 24-hour pain scores on movement, this was not statistically different than pain scores in the postoperative IVLI group (test of interaction: P = 0.68). There were no differences between intraoperative IVLI and postoperative IVLI for postoperative in-hospital nausea, vomiting, time to bowel movement, and length of hospital stay.

Conclusion: Continuing an IVLI beyond 60 minutes after surgery has no added analgesic or gastrointestinal benefit. Further research is needed to clarify an optimal IVLI regimen and end time.