Comparison of Analgesic Method in Laparoscopic Gastrectomy Using External Oblique Intercostal Block Versus Wound Infiltration: A Randomized Controlled Trial

Background: External oblique intercostal block (EOIB) is effective in relieving pain in the T6 to T10 dermatomes; however, there is limited evidence comparing EOIB with conventional regional anesthesia. In this randomized controlled trial, it was hypothesized that EOIB would provide more effective analgesia than wound infiltration (WI) in laparoscopic gastrectomy. Methods: Thirty-two patients (aged 20–85 years) with American Society of Anesthesiologists Performance Status of 1 to 2, scheduled for laparoscopic gastrectomy, were randomly divided into EOIB and WI groups. Both procedures were performed using 40 mL of 0.25% levobupivacaine. The primary outcome was the numerical rating scale (NRS) score 12 h postoperatively. Secondary outcomes were NRS at 2, 24, and 48 h postoperatively, variation in quality of recovery-15 score on postoperative days 1 and 2 from preoperative baseline, postoperative fentanyl consumption, and variation in World Health Organization Disability Assessment Scale 2.0 scores between baseline and 3 months postoperatively. Plasma concentrations of levobupivacaine and pinprick sensation in the T4–11 dermatomes post-EOIB were evaluated to determine the exploratory endpoints. Results: There were no differences in the NRS scores 12 h postoperatively at rest and during movement between the EOIB and WI groups (mean standard deviation 1.3 1.1 vs. 1.5 1.4 and 3.1 1.6 vs. 3.8 1.7, respectively). Secondary outcomes did not differ significantly between the groups. The time to peak plasma concentration of levobupivacaine following EOIB was 45 min. Conclusions: No significant differences in NRS scores were observed between the analgesic effects of EOIB and WI at 12 h postoperatively.