Intravenous Versus Perineural Ondansetron for Laparoscopic Sleeve Gastrectomy

Intravenous Versus Perineural Ondansetron as an Adjuvant in Autonomic Neural Blockade for Laparoscopic Sleeve Gastrectomy: A Two-Center, Randomized, Double-Blind, Non-inferiority Trial

This prospective randomized non-inferiority study will be conducted to compare the analgesic anti-emetic effects of intravenous ondansetron versus perineural ondansetron in patients undergoing laparoscopic sleeve gastrectomy.

Study Overview

• Status: Recruiting
• Conditions: Gastrectomy; Laparoscopic; Ondansetron
• Intervention / Treatment: Drug: Perineural ondansetron; Drug: Intravenous ondansetron

Detailed Description

Obesity and its associated disorders have significant implications for health, resulting in heightened productivity loss and reduced life expectancy while also negatively impacting the quality of life of patients. Surgical intervention is the most effective way to achieve sustainable weight loss in patients with obesity and to alleviate the associated comorbidities. Despite the current availability of minimally invasive bariatric surgical treatments, postoperative pain remains a significant issue. Vagal and sympathetic afferent signals originating from the gastrointestinal system stimulate the vomiting center, causing nausea and vomiting. Paragastric autonomic neural blockade (PANB) is a new method performed by injecting local anesthetic material into three to four separate points along the border between the lesser omentum and the stomach (from the esophagogastric junction to the distal antrum), the hepatoduodenal ligament, and the area covering the left gastric artery. This procedure aims to prevent visceral pain and symptoms of nausea and vomiting. Ondansetron is a serotonin receptor (5-HT3) antagonist used commonly to manage postoperative nausea and vomiting (PONV) through intravenous (IV) injection. It also has a local anesthetic effect and many studies used it as adjuvant in various regional anesthetic techniques. In this study, investigators will compare the combined antiemetic analgesic effects of IV and perineural (adjuvant to the local anesthetic bupivacaine in PANB) ondansetron. The investigators hypothesized that perineural administration of ondansetron will be non-inferior to the IV route regarding prophylaxis against PONV, and will provide superior postoperative analgesic effects by its local anesthetic enhancing action.

• Study Type: Interventional
• Enrollment (Estimated): 482
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Osama M Rehab, MD; Phone Number: 01095210806; Email: osamarehab@med.tanta.edu.eg

Study Locations

• Egypt
  • Gharbia Governorate
    • Tanta, Gharbia Governorate, Egypt, 31527
      • Recruiting
      • Tanta University Hospitals
      • Sub-Investigator: Doha M Bakr, MD
      • Principal Investigator: Osama M Rehab, MD
      • Contact: Osama M Rehab, MD; Phone Number: 01095210806; Email: osamarehab@med.tanta.edu.eg

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patients of either sex
• American Society Anesthesiologists physical (ASA) status II-III
• age between 18-65 years old
• Body mass index (BMI) >35 kg/m2 with comorbidity or > 40 kg/m2 -- undergoing laparoscopic sleeve gastrectomy with intraoperative surgeon performed laparoscopic paragastric autonomic neural blockade..

Exclusion Criteria:

• Allergy to experimental drugs.
• Known to have long QT, previous history of postoperative nausea and vomiting
• Abuse of alcohol, analgesia, or sedative antidepressant drugs
• Chronic pain disorders
• History of previous upper gastrointestinal system surgery, those with surgery-related complications during or after surgery.
• Liver or kidney failure
• Performance of concomitant procedures in addition to laparoscopic sleeve gastrectomy
• Anesthetic complications that may alter the postoperative management protocol.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Perineural ondansetron group; Para-gastric autonomic neural blockade will be performed (after separation of the stomach and performing the methylene blue leak test) using 20 ml solution containing 18 ml bupivacaine 0.5% plus 2 ml (4 mg) ondansetron. At the same time, 15 ml saline will be injected slowly IV over 15 minutes.	Drug: Perineural ondansetron; Para-gastric autonomic neural blockade will be performed (after separation of the stomach and performing the methylene blue leak test) using 20 ml solution containing 18 ml bupivacaine 0.5% plus 2 ml (4 mg) ondansetron. At the same time, 15 ml saline will be injected slowly IV over 15 minutes.
Active Comparator: Intravenous ondansetron group; Para-gastric autonomic neural blockade will be performed (after separation of the stomach and performing the methylene blue leak test) using 20 ml solution containing 18 ml bupivacaine 0.5% plus 2 ml saline. At the same time, 4 mg (2 ml) ondansetron mixed with 13 ml saline (total 15 ml) will be slowly injected IV over 15 minutes.	Drug: Intravenous ondansetron; Para-gastric autonomic neural blockade will be performed (after separation of the stomach and performing the methylene blue leak test) using 20 ml solution containing 18 ml bupivacaine 0.5% plus 2 ml saline. At the same time, 4 mg (2 ml) ondansetron mixed with 13 ml saline (total 15 ml) will be slowly injected IV over 15 minutes.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of vomiting in the early 8 hours after surgery.	Any attack of vomiting will be recorded for all patients.	8 hours after surgery.
Degree of postoperative pain at 1 hour after surgery as measured by the numerical rating scale pain score.	Numerical rating scale pain score (NRS) ranges from 0 = no pain to 10= worst pain.	1 hour after surgery.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Incidence of postoperative nausea and vomiting at 1 h, 8 h, and at 24 hours after surgery.	Any attack of nausea and vomiting will be recorded for all patients. Numerical rating scale from 0 (no nausea) to 10 (worst nausea) will be used to assess the severity of nausea.	24 hours after surgery.
Number of rescue anti-emetic doses in the first postoperative day.	Routine anti-emetics will be given every 8 hours in the form of IV metoclopramide 10 mg. Rescue anti-emetic medication in the form of ondansetron 8 mg slowly IV will be given. The total required dose and number of ondansetron boluses will be recorded.	24 hours after surgery.
Postoperative pain scores at 4 h, 8 h, and 24 hour after surgery.	Numerical rating scale pain score (NRS) ranges from 0 = no pain to 10= worst pain will be used to evaluate pain scores after surgery.	24 hours after surgery.
Time to first rescue opioid analgesic.	opioid dose will be given to patients with pain score ≥ 4.	24 hours after surgery.
Total opioid dose in the first day after surgery.	opioid dose will be given to patients with pain score ≥ 4.	24 hours after surgery.
Patient satisfaction	Likert-type scale of 0-5 points will assess satisfaction before discharge from the hospital .	24 hours after surgery.

Collaborators and Investigators

• Sponsor: Tanta University

Study record dates

Study Major Dates

• Study Start (Actual): February 16, 2025
• Primary Completion (Estimated): February 16, 2027
• Study Completion (Estimated): February 17, 2027

Study Registration Dates

• First Submitted: January 27, 2025
• First Submitted That Met QC Criteria: February 1, 2025
• First Posted (Actual): February 6, 2025

Study Record Updates

• Last Update Posted (Actual): May 15, 2026
• Last Update Submitted That Met QC Criteria: May 13, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Laparoscopic; Ondansetron; Gastrectomy
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Antiemetics; Autonomic Agents; Peripheral Nervous System Agents; Gastrointestinal Agents; Dermatologic Agents; Neurotransmitter Agents; Antipruritics; Serotonin 5-HT3 Receptor Antagonists; Serotonin Antagonists; Serotonin Agents; Ondansetron
• Other Study ID Numbers: 36264PR1032/1/25

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: The data will be available upon reasonable request from the corresponding author.
• IPD Sharing Time Frame: After completion of the study.
• IPD Sharing Access Criteria: The data will be available upon reasonable request from the corresponding author.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No