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

• A comparison of intravenous lidocaine infusions (IVLI) end times in bowel surgery was performed.
• We compared IVLIs lasting ≤ 60 minutes and those lasting > 60 minutes.
• Intravenous lidocaine infusion ≤ 60 minutes reduced pain scores at rest at 48 and 72 hours after surgery.
• There were no other differences between the two infusion durations.
• There is no added value of continuing an IVLI more than 60 minutes after surgery.

Study objectiveThere 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.DesignA 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 resultsSeven 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.ConclusionContinuing 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.