External Oblique Intercostal Plane Block for Postoperative Analgesia After Major Upper Abdominal Surgery

NCT ID: NCT07331441

Last Updated: 2026-01-09

Basic Information

• Recruitment Status: NOT_YET_RECRUITING
• Clinical Phase: NA
• Total Enrollment: 78 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2026-01-15
• Study Completion Date: 2026-04-20

Brief Summary

Postoperative pain after laparoscopic major upper abdominal surgery (e.g., gastric, hepatic, gallbladder, pancreatic surgery) is often severe, and inadequate analgesia may lead to increased opioid use, opioid dependence, and poor functional recovery. Current analgesic techniques such as neuraxial block have safety concerns (e.g., hypotension, neurological injury), while transversus abdominis plane (TAP) block is ineffective for blocking the lateral cutaneous branches of intercostal nerves in the upper abdomen. The External Oblique Intercostal Plane Block (EOIB) is a novel regional block technique that has shown promise in reducing postoperative opioids and pain in small-scale studies, but evidence for its use in major upper abdominal surgery is limited. This randomized controlled trial (RCT) aims to evaluate the analgesic efficacy and safety of bilateral EOIB combined with standard multimodal analgesia versus standard multimodal analgesia alone in patients undergoing elective laparoscopic major upper abdominal surgery. The primary outcome is the total postoperative opioid consumption (measured as Morphine Milligram Equivalents, MME) within 24 hours. Secondary and additional outcomes include pain scores (Verbal Rating Scale, VRS), recovery quality (QoR-15 scale), incidence of adverse events, and hospital stay.

Detailed Description

Postoperative pain after major upper abdominal surgery is common and may delay recovery and increase opioid-related adverse effects. The External Oblique Intercostal Plane Block (EOIB) is a novel fascial plane block intended to improve analgesia for upper abdominal incisions.

This study is a prospective, single-center, randomized, assessor-blinded controlled trial in adults (18-85 years, ASA I-III) scheduled for elective major upper abdominal laparoscopic-assisted surgery (e.g., gastric, hepatic, gallbladder, pancreatic procedures) with expected operative time ≥2 hours and planned use of IV patient-controlled analgesia (PCA). Participants will be randomized 1:1 using a computer-generated, variable block-size sequence with allocation concealment via opaque sealed envelopes. The block-performing anesthesiologist will not collect outcomes; outcome assessors will be blinded to group assignment.

After induction of general anesthesia and before surgical incision, patients in the intervention group will receive ultrasound-guided bilateral EOIB at the 6th rib level using an in-plane technique; 15 mL per side of a mixture of 0.75% ropivacaine and normal saline will be injected. Control participants will receive no regional block. All participants will receive standardized multimodal analgesia including IV PCA, antiemetic prophylaxis (dexamethasone 5 mg; ondansetron as needed), and NSAID use per ERAS practice.

The primary endpoint is total opioid consumption during the first 24 hours after surgery, expressed as IV morphine milligram equivalents (MME), including PCA and rescue opioids. Secondary outcomes include postoperative pain scores (0-10 verbal rating scale) at prespecified time points (including 24, 48, and 72 hours; at rest and with activity as applicable), quality of recovery (QoR-15 at 24/48/72 hours), opioid consumption at 24-48 hours, postoperative nausea and vomiting within 72 hours, intraoperative hemodynamic events, time to first flatus, and postoperative length of stay.

Conditions

Abdominal Surgery; Postoperative Pain

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: TREATMENT
• Blinding Strategy: SINGLE

Study Groups

EOIB Block

Participants receive ultrasound-guided bilateral External Oblique Intercostal Plane Block (EOIB) after induction of general anesthesia and before surgical incision, using ropivacaine (15 mL per side), in addition to standard multimodal analgesia (including IV PCA and ERAS-based non-opioid analgesics).

Group Type: EXPERIMENTAL

External Oblique Intercostal Plane Block

Intervention Type: PROCEDURE

Ultrasound-guided bilateral external oblique intercostal plane block (EOIB) performed after induction of general anesthesia and before surgical incision. Using an in-plane technique at the 6th rib level, 15 mL per side of local anesthetic solution (ropivacaine 0.75% diluted with normal saline) is injected between the external oblique muscle and the intercostal muscle. Standard multimodal analgesia is also provided to all participants.

Usual Analgesia

Participants receive standard multimodal analgesia without any regional block. Analgesia includes IV patient-controlled analgesia (PCA) and other non-opioid analgesics per the institutional ERAS protocol.

Group Type: SHAM_COMPARATOR

Standard multimodal analgesia

Intervention Type: OTHER

Standard multimodal analgesia per institutional ERAS practice, including intravenous patient-controlled analgesia (IV PCA) with opioids and adjunct non-opioid analgesics (e.g., NSAIDs and/or acetaminophen) with antiemetic prophylaxis as needed. No regional block is administered.

Interventions

External Oblique Intercostal Plane Block

Ultrasound-guided bilateral external oblique intercostal plane block (EOIB) performed after induction of general anesthesia and before surgical incision. Using an in-plane technique at the 6th rib level, 15 mL per side of local anesthetic solution (ropivacaine 0.75% diluted with normal saline) is injected between the external oblique muscle and the intercostal muscle. Standard multimodal analgesia is also provided to all participants.

Intervention Type: PROCEDURE

Standard multimodal analgesia

Standard multimodal analgesia per institutional ERAS practice, including intravenous patient-controlled analgesia (IV PCA) with opioids and adjunct non-opioid analgesics (e.g., NSAIDs and/or acetaminophen) with antiemetic prophylaxis as needed. No regional block is administered.

Intervention Type: OTHER

Other Intervention Names

EOIB; Usual analgesia

Eligibility Criteria

Inclusion Criteria

• Obtain written informed consent from participants or their legal representatives
• Age between 18 and 85 years
• American Society of Anesthesiologists (ASA) physical status classification I-III
• Scheduled for elective laparoscopic major upper abdominal surgery (e.g., gastric, hepatic, gallbladder, pancreatic surgery)
• Expected surgical duration ≥ 2 hours
• Ability to use the intravenous patient-controlled analgesia (IV PCA) system

Exclusion Criteria

• Hepatic disease (liver enzyme levels ≥ 2× the upper limit of normal)
• Renal disease (serum creatinine levels ≥ 2× the upper limit of normal)
• Allergy to local anesthetics or known study-related drugs
• Pregnancy or lactation
• Low surgical incision site (not involving the upper abdominal wall innervated by T6-T10 nerves)
• Coagulopathy or current use of anticoagulant medications
• Opioid use for more than 2 weeks in the past 6 months

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 85 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Jun Zhang

OTHER

Sponsor Role: lead

Responsible Party

Jun Zhang

Department of Anesthesiology of Shanghai cancer center

Responsibility Role: SPONSOR_INVESTIGATOR

Principal Investigators

Jun Zhang, PhD

Role: STUDY_DIRECTOR

Fudan University

Central Contacts

Jun Zhang, PhD

Role: CONTACT

snapzhang@aliyun.com

0216417559001

Other Identifiers

2512335-12

Identifier Type: -

Identifier Source: org_study_id