Wound infiltration with local anesthetics during cesarean delivery with intrathecal opioids: A systematic review and meta-analysis of randomized control trials.

OBJECTIVE: To evaluate the effect on maternal pain of local anesthetic wound infiltration for intra-cesarean delivery analgesia in patients who also received intrathecal opioids. DATA SOURCES: Scopus, PubMed, and Cochrane Central Register of Controlled Trials were searched from the inception of each database to August 2023. STUDY ELIGIBILITY CRITERIA: All randomized controlled trials (RCTs) comparing the use of local anesthetic wound infiltration at the time of cesarean delivery versus no such infiltration in patients who also received intrathecal opioids. The primary outcome was pain scores at 24 h with movement. Secondary outcomes included pain scores at 12, 48, 72 h with movement and at rest, opioid consumption at 48 h, length of hospitalization, and side effects. STUDY APPRAISAL AND SYNTHESIS METHODS: Results were summarized as mean difference (MD) or risk ratio (RR) with associated 95% confidence intervals. Quality of studies was evaluated by Cochrane Handbook for Systematic Reviews of Interventions for judging risk of bias. Heterogeneity was measured using I-squared (Higgins I2). RESULTS: Eight RCTs (n = 762) comparing local anesthetic wound infiltration to no infiltration during cesarean delivery met inclusion criteria. Local anesthetic (usually with ropivacaine, bupivacaine, or levobupivacaine) wound infiltration was associated with significantly lower pain scores with movement compared to no infiltration (MD, -9.07 (-14.62, -3.53) (I 2 = 5%) at 48 h. Additional outcomes showed decreased but not statistically different pain scores at rest: 24 h (MD, -2.57 [-7.79, 2.65]), 48 h (-3.98 [MD, -8.18, 0.23]), and 72 h (MD, -4.28 [-9.56, 1.00]). Analysis of morphine consumption equivalents at 48 h showed a significant decrease in the wound infiltration group (MD, -3.09 [-4.46, -1.72], I 2 = 46%). Side effects were similar in both groups (nausea, vomiting, pruritus, and sedation). CONCLUSION: Single-dose local anesthetic wound infiltration-of levobupivacaine, ropivacaine, or bupivacaine-administered subfascial at the time of cesarean delivery with intrathecal opioids is associated with reduced postoperative morphine consumption. The pain intensity scores at rest or with movement at 24 h postoperatively are decreased yet not significantly different, but significantly decreased at 48 h with movement and maternal side effects are comparable.