Intravenous Versus Perineural Ondansetron for Laparoscopic Sleeve Gastrectomy

May 13, 2026 updated by: Osama Rehab, Tanta University

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

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

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

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
482

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

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:

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

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

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

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

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
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

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Incidence of vomiting in the early 8 hours after surgery.
Time Frame: 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.
Time Frame: 1 hour after surgery.
Numerical rating scale pain score (NRS) ranges from 0 = no pain to 10= worst pain.
1 hour after surgery.

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Incidence of postoperative nausea and vomiting at 1 h, 8 h, and at 24 hours after surgery.
Time Frame: 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.
Time Frame: 24 hours after surgery.
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.
Time Frame: 24 hours 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.
Time Frame: 24 hours after surgery.
opioid dose will be given to patients with pain score ≥ 4.
24 hours after surgery.
Total opioid dose in the first day after surgery.
Time Frame: 24 hours after surgery.
opioid dose will be given to patients with pain score ≥ 4.
24 hours after surgery.
Patient satisfaction
Time Frame: 24 hours after surgery.
Likert-type scale of 0-5 points will assess satisfaction before discharge from the hospital .
24 hours after surgery.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Tanta University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
February 16, 2025

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
February 16, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
February 17, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
January 27, 2025

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 1, 2025

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
February 6, 2025

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
May 15, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 13, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
May 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant 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

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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