External oblique intercostal plane block for postoperative analgesia: A systematic review and meta-analysis of...

The external oblique intercostal plane (EOIP) block targets the lateral and anterior branches of T6-T10 intercostal nerves, providing upper abdominal wall analgesia. Its superficial location and ease in the supine position make it a promising option for multimodal analgesia. This systematic review and meta-analysis evaluated its efficacy versus other fascial plane blocks, wound infiltration, or no block in adults undergoing abdominal surgery.

Following PRISMA guidelines (PROSPERO-CRD420251057391), databases were searched for randomised controlled trials (RCTs) comparing the EOIP block with other fascial plane blocks, wound infiltration, or no block. The primary outcome was 24-hour postoperative opioid consumption. The secondary outcomes were pain scores at rest and movement, intraoperative opioid use, time to first analgesic request, rescue analgesia needs, quality of recovery (QoR)-15 scores, and postoperative nausea and vomiting (PONV). Trial sequential analysis (TSA) was performed to assess the robustness of the primary outcome.

Seventeen RCTs (n = 1032) were included. EOIP block significantly reduced 24-hour opioid consumption [standardised mean difference (SMD): -1.32; 95% confidence interval (CI): -1.83, -0.82; P < 0.001); lowered pain scores at 6, 12, and 24 hours; decreased intraoperative fentanyl use; prolonged analgesia duration; reduced rescue analgesia needs; improved QoR-15 scores; and lowered PONV incidence. TSA confirmed conclusive evidence for EOIP versus no block but indicated further trials are needed versus fascial plane blocks.

As compared to other fascial plane blocks, wound infiltration, or no block, the EOIP block provides opioid-sparing analgesia, sustained pain relief, and enhanced recovery in abdominal surgery. However, due to heterogeneity and a low-to-moderate certainty of evidence, further high-quality RCTs are warranted.