Laparoscopic Gastrectomy Using External Oblique Intercostal Block Versus Wound Infiltration: A Trial Protocol.

Objective: A novel external oblique intercostal block (EOIB) might have analgesic effects on T6-10 and be indicated for laparoscopic gastrectomy. However, EOIB effects on postoperative pain are unknown. We aim to generate evidence to support such EOIB application. We will compare the efficacy of EOIB and wound infiltration (WI) in a single-center, single-blind, randomized controlled trial.

Methods: We will assess plasma concentrations of levobupivacaine after EOIB, its pharmacokinetics, and the pinprick test in patients randomly assigned to receive EOIB or WI before laparoscopic or robot-assisted gastric distal or total gastrectomy. The EOIB and WI will start after general anesthesia induction with 20 and 40 mL of 0.25% levobupivacaine per side, respectively, before skin closure. The outcomes will be numeric rating scale (NRS) scores at 12 h postoperatively (primary) and postoperative NRS scores at 2, 24, and 48 h; fentanyl application; QoR-15 scores on postoperative days 1, 2, and 7; and World Health Organization Disability Assessment Schedule 2.0 scores at 3 months (secondary).

Conclusions: We hope that our study will provide evidence to support EOIB application in laparoscopic surgery. Plasma concentrations will help determine levobupivacaine pharmacokinetics, which if similar to conventional nerve blocks, will indicate EOIB's safety.