Ultrasound-Guided External Oblique Intercostal Plane Block for Postoperative Analgesia in Laparoscopic Sleeve Gastrectomy: A Prospective, Randomized, Controlled, Patient and Observer-Blinded Study

Purpose: The external oblique intercostal plane (EOI) block is a novel block technique for anterolateral upper abdominal wall analgesia. The superficial nature of the external oblique intercostal plane allows it to be easily identified even in patients with obesity. The aim of this study was to test the hypothesis that EOI block would reduce IV morphine consumption within 24 h after laparoscopic sleeve gastrectomy. Materials and Methods: Patients were randomly assigned to one of two groups: EOI block group and control group. The patients in the EOI block group received ultrasound-guided bilateral EOI block with a total of 40 ml 0.25% bupivacaine after anesthesia induction. The patients in the control group received no intervention. Postoperatively, all the patients were connected to an intravenous patient controlled analgesia (PCA) device containing morphine. The primary outcome of the study was IV morphine consumption in the first postoperative 24 h. Results: The median [interquartile range] morphine consumption at 24 h postoperatively was significantly lower in the EOI block group than in the control group (7.5 [3.5 to 8.5] mg vs 14 [12 to 20] mg, p = 0.0001, respectively). Numerical rating scale (NRS) scores at rest and during movement were lower in the EOI block group than in the control group at 2, 6, and 12 h but were similar at 24 h. No block-related complications were observed in any patients. Conclusion: The results of the current study demonstrated that bilateral EOI block reduced postoperative opioid consumption and postoperative pain in patients with obesity undergoing laparoscopic sleeve gastrectomy. Trial Registration: Clinicaltrials.gov identifier: NCT05663658. Graphical Abstract: (Figure presented.).