Effect of Ondansetron on Patient Tolerance, Efficacy and Endoscopist Workload in Unsedated Endoscopy for Upper Gastrointestinal Bleeding

The goal of this clinical trial is to evaluate whether intravenous ondansetron can improve patient tolerance and reduce discomfort during unsedated emergency esophagogastroduodenoscopy (EGD). The main questions it aims to answer are:

• Does pre-procedural administration of ondansetron improve patient cooperation during emergency EGD?
• Does it improve endoscopic field visibility and improve the success rate of initial endoscopic hemostasis？
• Does it reduce the operator's perceived workload or stress?

Researchers will compare patients who received intravenous ondansetron with patients who received placebo to see if ondansetron can reduce patient discomfort and improve patient cooperation, therefore improve the quality of the procedure.

Participants will receive either intravenous ondansetron and dyclonine hydrochloride mucilage or intravenous saline and dyclonine hydrochloride mucilage prior to the endoscopic procedure.

Study Overview

• Status: Not yet recruiting
• Conditions: Esophagogastroduodenoscopy; Upper Gastrointestinal Bleeding (UGIB)
• Intervention / Treatment: Drug: intravenous ondansetron; Drug: Placebo

• Study Type: Interventional
• Enrollment (Estimated): 80
• Phase: Phase 4

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• Presence of suspected or confirmed upper gastrointestinal bleeding with an indication for emergent endoscopic intervention.
• Capability to provide informed consent.

Exclusion Criteria:

• Presence of any contraindication to upper gastrointestinal endoscopy.
• Concurrent severe primary diseases of the respiratory, cardio-cerebrovascular, renal, central nervous, or hematologic systems.
• Pregnancy.
• Presence of neuropsychiatric disorders, including severe depression or severe anxiety.
• Presence of a known history of cardiac arrhythmia.
• Allergic to dyclonine hydrochloride or ondansetron.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Placebo Comparator: control	Drug: Placebo; Intravenous administration of 8 ml saline 0.5-1h prior to endoscopic procedure and gurgle 10 ml dyclonine hydrochloride viscous solution (0.01 g/mL) 15 min prior to the endoscopic procedure.
Experimental: intravenous ondansetron	Drug: intravenous ondansetron; Intravenous administration of 8 mg ondansetron 0.5-1h prior to endoscopic procedure and gurgle 10 ml dyclonine hydrochloride viscous solution (0.01 g/mL) 15 min prior to the endoscopic procedure.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
patient cooperation	evaluated by the endoscopist in numeric rating scale, 0 stands for not good at all, 10 stands for completely satisfied.	from the beginning to the end of the endoscopic procedure

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
gagging intensity of patient	gagging intensity of patient evaluated by the endoscopist, in numeric rating scale, 0 means none, 10 means extremely intense.	from the beginning to the end of the endoscopic procedure
visualization quality	Overall endoscopic visualization was evaluated at 4 locations including (i) gastric fundus, (ii) corpus, (iii) antrum, and (iv) duodenal bulb. The score is rated in the following criteria: 0, less than 25% of the surface was visible; 1, 25%-75% visible; and 2, more than 75% visible. The total score range was 0-8.	During the endoscopic procedure.
Success rate of initial endoscopic hemostasis	the proportion of patients in each group who achieved hemostasis with a single endoscopic intervention	from the beginning to the end of the endoscopic procedure
Proportion of patients needing repeat endoscopy within 72 hours	The proportion of patients who underwent a repeat upper gastrointestinal endoscopy for suspected rebleeding within 72 hours following the completion of the initial endoscopic procedure.	from the time of the endoscopic procedure to 3 days after the endoscopic procedure.
Recurrence of UGIB in 7 days	The proportion of patients in whom hemostasis was initially achieved by endoscopy, but who subsequently experienced recurrent bleeding within 7 days. Recurrent bleeding is defined by the occurrence of any of the following: hematemesis, melena, hematochezia, hemodynamic instability, or endoscopic confirmation of recurrent bleeding at the original site.	from the day of the procedure to 7 days after it
endoscopist workload	Self-assessed by the endoscopist immediately after the procedure. It is measured across six dimensions-mental demand, physical demand, temporal demand, effort, performance, and frustration/anxiety-using a 0-100 mm visual analogue scale for each, where 0 represents "very low" and 100 represents "very high".	From the beginning to the end of the endoscopic procedure
adverse event	Any adverse medical event occurring during the endoscopic procedure, regardless of its relationship to the study medication.	from the beginning of the intervention to 1 week after the endoscopic procedure.

Collaborators and Investigators

• Sponsor: Peking Union Medical College Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): January 1, 2026
• Primary Completion (Estimated): May 1, 2026
• Study Completion (Estimated): June 1, 2026

Study Registration Dates

• First Submitted: January 2, 2026
• First Submitted That Met QC Criteria: January 2, 2026
• First Posted (Actual): January 13, 2026

Study Record Updates

• Last Update Posted (Actual): January 13, 2026
• Last Update Submitted That Met QC Criteria: January 2, 2026
• Last Verified: January 1, 2026

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Digestive System Diseases; Gastrointestinal Diseases; Hemorrhage; Pathological Conditions, Signs and Symptoms; Gastrointestinal Hemorrhage
• Other Study ID Numbers: ON-UGIB25

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No