External Oblique Intercostal Block (EOICB) for Laparoscopic Cholecystectomy

Official title

Paravertebral Block or External Oblique Intercostal Block? A Comparative Analysis of Pain and Opioid Consumption After Laparoscopic Cholecystectomy: A Randomized Controlled Trial

Overview

This single-center, prospective, randomized controlled trial aims to compare the effects of paravertebral block (PVB), external oblique intercostal (EOI) block, and intravenous patient-controlled analgesia (PCA) with tramadol on postoperative pain and opioid consumption in patients undergoing elective laparoscopic cholecystectomy. The primary endpoint is total tramadol consumption within 24 hours postoperatively. Secondary outcomes include pain scores, additional analgesic use, incidence of nausea/vomiting, mobilization time, and length of hospital stay.

Detailed description

This single center, prospective, randomised controlled clinical trial is designed to evaluate analgesic efficacy and opioid sparing effect of ultrasound guided paravertebral block (PVB) and external oblique intercostal (EOI) block versus systemic opioid based analgesia in adult patients undergoing elective laparoscopic cholecystectomy under general anesthesia.

Pain after laparoscopic cholecystectomy is often moderate to severe during the first 24 hours , and has somatic and visceral components . Regional approaches that target thoracoabdominal dermatomes and visceral afferents may provide superior analgesia, allow for earlier mobilisation, and reduce opioid-related adverse effects compared with intravenous opioid regimens alone. PVB provides unilateral segmental blockade at thoracic paravertebral level, while the EOI block deposits local anaesthetic in the fascial plane between the external oblique and intercostal muscles, with spread to relevant thoracoabdominal nerves.

In a parallel-group design, participants will be randomly allocated to bilateral thoracic PVB, bilateral EOI block or no truncal block with standard systemic analgesia. All regional blocks will be performed under ultrasound guidance after induction of general anaesthesia. Standardised volumes and concentrations of long-acting local anaesthetic will be used according to institutional practice. The control group will receive patient-controlled intravenous opioid analgesia as part of a multimodal approach.

Standardisation of intraoperative monitoring and technique of general anaesthesia according to departmental protocols will be done for perioperative anaesthetic management. Postoperative pain intensity will be assessed by an 11-point Numerical Rating Scale at specified time points during the first 24 hours. Rescue analgesia will be administered according to a predefined algorithm. The trial's purpose is to compare postoperative opioid use between groups and to investigate differences in pain trajectories and opioid-related adverse events in routine clinical conditions.

Interventions

• Procedure Paravertebral Block (PVB)
  Ultrasound-guided bilateral thoracic paravertebral block performed after induction of general anesthesia using 0.25% bupivacaine, 20 mL per side (total 40 mL).
• Procedure External Oblique Intercostal Block (EOI Block)
  Ultrasound-guided bilateral external oblique intercostal block performed after induction of general anesthesia with 0.25% bupivacaine, 20 mL per side (total 40 mL), injected between the external oblique and intercostal muscles.
• Drug Tramadol IV Patient-Controlled Analgesia (PCA)
  Intravenous patient-controlled analgesia (PCA) programmed to deliver tramadol with a maximum dose of 400 mg in 24 hours. Standard analgesia protocol includes IV paracetamol 1 g every 8 hours.

Primary outcome measures

• 24-hour postoperative tramadol consumption [Time frame: Within the first 24 hours after surgery.]

Secondary outcome measures (4)

• Postoperative pain scores at rest [Time frame: 1, 6, 12, and 24 hours postoperatively]
• Incidence of postoperative nausea and vomiting [Time frame: Within 24 hours postoperatively]
• Incidence of block-related complications [Time frame: Intraoperative and first 24 hours after block]
• Patient satisfaction with analgesia [Time frame: 24 hours postoperatively]

Eligibility criteria

Inclusion criteria

• Age between 18 and 65 years
• Scheduled for elective laparoscopic cholecystectomy under general anesthesia
• ASA physical status I-III
• Able to understand the study procedure and provide informed consent

Exclusion criteria

Patient refusal or inability to provide informed consent

Allergy or contraindication to local anesthetics, tramadol, or study medications

Coagulopathy or current anticoagulant therapy

Local infection at the planned block injection site

Severe hepatic or renal impairment

Chronic opioid use or opioid dependence

Neurological or psychiatric disorders affecting pain perception or communication

Pregnancy or breastfeeding

Body mass index (BMI) > 35 kg/m²

Conversion to open cholecystectomy during surgery

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Single blind

Primary purpose

Treatment

Study locations

Turkey (Türkiye) · 1 center

• Cukurova University Faculty of Medicine — Adana

Publications

• Hawker GA, Mian S, Kendzerska T, French M. Measures of adult pain: Visual Analog Scale for Pain (VAS Pain), Numeric Rating Scale for Pain (NRS Pain), McGill Pain Questionnaire (MPQ), Short-Form McGill Pain Questionnaire (SF-MPQ), Chronic Pain Grade Scale (CPGS), Short Form-36 Bodily Pain Scale (SF-36 BPS), and Measure of Intermittent and Constant Osteoarthritis Pain (ICOAP). Arthritis Care Res (Ho PMID 22588748
• Erskine RN, White L. "A review of the external oblique intercostal plane block - a novel approach to analgesia for upper abdominal surgery". J Clin Anesth. 2022 Nov;82:110953. doi: 10.1016/j.jclinane.2022.110953. Epub 2022 Aug 19. No abstract available. PMID 35994942
• Hamilton DL, Manickam BP, Wilson MAJ, Abdel Meguid E. External oblique fascial plane block. Reg Anesth Pain Med. 2019 Jan 11:rapm-2018-100256. doi: 10.1136/rapm-2018-100256. Online ahead of print. No abstract available. PMID 30635518
• Hamilton DL, Manickam BP. Is a Thoracic Fascial Plane Block the Answer to Upper Abdominal Wall Analgesia? Reg Anesth Pain Med. 2018 Nov;43(8):891-892. doi: 10.1097/AAP.0000000000000838. No abstract available. PMID 30339615
• Kus A, Gurkan Y, Arslan ZI, Akgul AG, Aksu C, Toker K, Solak M. [Our ultrasound-guided paravertebral block experiences in thoracic surgery]. Agri. 2015;27(3):139-42. doi: 10.5505/agri.2015.59885. Turkish. PMID 26356102
• Barazanchi AWH, MacFater WS, Rahiri JL, Tutone S, Hill AG, Joshi GP; PROSPECT collaboration. Evidence-based management of pain after laparoscopic cholecystectomy: a PROSPECT review update. Br J Anaesth. 2018 Oct;121(4):787-803. doi: 10.1016/j.bja.2018.06.023. Epub 2018 Aug 7. PMID 30236241
• O'Donovan B, Martin B. The Novel Use of an External Oblique Nerve Catheter After Open Cholecystectomy. Cureus. 2021 Feb 26;13(2):e13580. doi: 10.7759/cureus.13580. PMID 33796423
• Alper I, Ulukaya S, Yuksel G, Uyar M, Balcioglu T. Laparoscopic cholecystectomy pain: effects of the combination of incisional and intraperitoneal levobupivacaine before or after surgery. Agri. 2014;26(3):107-12. doi: 10.5505/agri.2014.42650. PMID 25205408

Identifiers

NCT: NCT07241949 · 2024-KAEK-33

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗