Analgesic efficacy of external oblique intercostal plane block in adults undergoing abdominal surgery: systematic...

Analgesic efficacy of the novel external oblique intercostal plane block (EOIB) is inconclusive. Therefore, the aim of this systematic review and meta-analysis was to synthesize the evidence for analgesic efficacy of EOIB in adults undergoing abdominal surgery.

Electronic databases were searched until 31^st May, 2025. Randomized controlled trials (RCTs) were considered provided they reported the difference in 24 h postoperative opioid consumption (primary objective). Secondary objectives were evaluation of static and dynamic pain scores, and other patient centric measures.

Sixteen RCTs (972 patients) were included. EOIB significantly reduced 24 h postoperative opioid consumption (mean difference (MD): -7.67 mg; 95% CI: -12.12 to -3.21; P<0.001; I²=98%; prediction interval -26.96 to 11.53). Subgroup analysis revealed significant reduction in opioid consumption with EOIB vs. no blocks (MD: -9.86 mg; 95% CI: -13.44 to -6.28; P<0.001; I²=95%;). EOIB significantly decreased static and dynamic pain scores at all-time points and the need for rescue analgesia. The MD crossed the minimum clinically important difference (MCID) vs. no blocks only for static pain scores at 6 and 12 h and dynamic pain scores at 12 h. However, the 95% CI for MCID crossed the null line precluding definitive clinical effectiveness. No significant differences were found in other secondary outcomes. Required information size for benefit or futility for a difference in 24 h opioid consumption was 758 patients between EOIB and the subcostal transversus abdominis plane block group.

EOIB provides superior analgesic efficacy vs. no blocks but the clinical effectiveness remains uncertain. Analgesic superiority over other blocks is inconclusive.