Analgesic effect of intraperitoneal local anesthetic in surgery: an overview of systematic reviews.

ABSTRACT

BACKGROUND: Intraperitoneal local anesthetic (IPLA) reduces postoperative pain as shown by previous systematic reviews. The purpose of this review was to compare the efficacy of IPLA between different types of procedure and to formulate GRADE recommendations for the use of IPLA. MATERIALS AND METHODS: A systematic search for systematic reviews of the effect of IPLA, versus no IPLA or placebo, on pain after any surgical procedure. Databases included in the study were MEDLINE, EMBASE, CDSR, and DARE. Two reviewers independently undertook searches, selected studies, extracted data, and assessed the risk of bias. Meta-analysis was by random effects. Recommendation was by GRADE. The main outcome measure was self-reported early postoperative pain scores. RESULTS: Searches uncovered nine systematic reviews. This study included randomized trials numbered 76, representing 4000 participants, 2022 in IPLA and 1978 in control groups. Six reviews scored at low risk of bias and three at high risk. Meta-analysis demonstrated that IPLA reduced the mean pain score (0-10 scale) by 0.95 point (95% confidence interval 0.73-1.17). Excluding laparoscopic cholecystectomy, the effect size increased to 1.52 (95% confidence interval 1.15-1.88). Heterogeneity was high overall at I2 = 91.7% but on excluding laparoscopic cholecystectomy trials reduced to I2 = 31.3%. CONCLUSIONS: IPLA could be considered a viable option for early postoperative analgesia in certain laparoscopic operations. Further research on the effect of IPLA on procedures other than laparoscopic cholecystectomy would help clarify its place in a postoperative analgesia protocol.