Evaluation of ropivacaine in external oblique intercostal block for analgesia in major upper abdominal surgery: a randomized controlled clinical trial

Background: To evaluate the efficacy and safety of bilateral external oblique intercostal (EOI) nerve block using ropivacaine for postoperative analgesia in patients undergoing major upper abdominal surgery. Methods: This prospective, randomized controlled trial enrolled patients who were randomly assigned to either the control group or the EOI group using a computer-generated randomization table. The primary outcome was sufentanil consumption via patient-controlled analgesia within 24 hours postoperatively. Pain intensity was assessed using the visual analog scale (VAS). Statistical analyses were performed using t-test and the Mann-Whitney U-test to compare analgesic efficacy and safety between the two groups. Results: A total of 78 patients were included in the study. Data analysis showed that patients from the EOI group had significantly lower sufentanil consumption at 24 hours postoperatively than those of the control group (median: 52 µg (50–54) vs. 54 µg (52–54); difference in medians with 95% confidence interval (CI): 0.000 to 2.000, p = 0.027, Mann-Whitney U-test with Hodges-Lehmann estimate). At 1 hour post-surgery, the control group had a significantly higher VAS score for incision pain compared to the EOI group (median: 2 (1–4) vs. 1 (0–2), p = 0.005). Additionally, tramadol consumption was significantly higher in the control group than in the EOI group at 1 hour postoperatively (median: 0 (0–50) vs. 0 (0–0), p = 0.038). No significant differences were observed in other secondary outcome parameters. Conclusions: EOI nerve block with ropivacaine can effectively reduce postoperative incision pain, minimizes the need for rescue analgesics, and exhibits a favorable safety profile in patients undergoing major upper abdominal surgery. Chinese Clinical Trial Registry: ChiCTR2400089685.