Transversus Abdominis Plane Block Compared with Wound Infiltration for Postoperative Analgesia Following Cesarean Delivery: a Systematic Review and Network Meta-analysis

Purpose: This systematic review and network meta-analysis (NMA) compared postoperative analgesic efficacy of transversus abdominis plane (TAP) blocks with that of wound infiltration for Cesarean delivery (CD) without long-acting neuraxial opioid administration.

Methods: We sought randomized-controlled trials comparing TAP vs wound infiltration, and inactive control vs either TAP or wound infiltration. Wound infiltration included single-dose infiltration (WI), or continuous infusion via a catheter (WC). The primary outcome was 24 hr opioid consumption. Secondary outcomes included 12 and 24 hr pain scores (resting and movement), time to first analgesia request, incidence of postoperative nausea and vomiting (PONV), maternal sedation, and pruritus. We performed a NMA incorporating both direct and indirect comparisons and reported standardized mean differences and odds ratios with 95% confidence intervals for continuous and dichotomous outcomes.

Results: Forty-two studies were included, comprising 2,906 participants. Transversus abdominis plane blocks and WC were associated with significantly lower 24 hr opioid consumption than inactive controls, but there were no significant differences between WI and inactive controls. There was no statistically significant difference in 24 hr opioid consumption between TAP blocks and WC or WI techniques. The network ranking of treatments was TAP block, followed by WC or WI. No significant differences were shown between TAP, WC, and WI groups for 24 hr pain scores, time to first analgesia, PONV, sedation, and pruritus. Quality of evidence was moderate for most of the outcomes assessed.

Conclusion: In the absence of long-acting neuraxial opioid after CD, single-dose TAP blocks and WC are effective opioid-sparing strategies.