Effect of Different Water Injection Temperatures on the Safety and Comfort of Patients Undergoing Ultrasound Endoscopy of Small Probes Under Intravenous Anesthesia

Miniprobe endoscopic ultrasonography (mEUS) is a key diagnostic modality for gastrointestinal (GI) mucosal or submucosal lesions, requiring water infusion to eliminate intraluminal air and improve image clarity. However, the optimal water temperature for sedated mEUS remains uncertain-previous studies suggest water temperature may affect GI peristalsis, haemodynamics, image quality, and patient safety/comfort, but no research has focused on this topic in sedated mEUS.

This is a prospective, multicentre, double-blind, randomized controlled study. Eligible patients (≥18 years with GI mucosal/submucosal lesions requiring sedated mEUS) are randomly assigned to three groups based on water temperature: cold water (6-10 °C), warm water (20-24 °C), and hot water (35-39 °C). The primary objectives are to evaluate the effects of different water temperatures on mEUS image quality (standardized scoring) and diagnostic accuracy. Secondary outcomes include GI peristaltic grade, haemodynamic indices (measured at 6 time points), adverse events, and patient somatic/psychological feeling, comfort, and satisfaction scores.

The study aims to identify the optimal water temperature that reduces GI peristalsis, improves mEUS diagnostic performance, and ensures patient safety and comfort during sedated mEUS, providing evidence for standardized clinical practice.

Study Overview

• Status: Completed
• Conditions: Small Probe Ultrasound Endoscopy; The Water Temperature
• Intervention / Treatment: Other: Change the water injection temperature

• Study Type: Observational
• Enrollment (Actual): 270

Contacts and Locations

Study Locations

• China
  • Hunan
    • Changsha, Hunan, China, 410013
      • he Third Xiangya Hospital of Central South University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 14 years to 71 years (Adult, Older Adult)
• Accepts Healthy Volunteers: N/A

• Sampling Method: Probability Sample

Study Population

In the Third Xiangya Hospital of Central South University, the First Affiliated Hospital of South China University, the South China Hospital Affiliated to the University of South China, the Hunan Provincial People's Hospital, and the First People's Hospital of Changde City, patients with small probe ultrasound endoscopy under intravenous anesthesia due to gastrointestinal bulge lesions.

Description

Inclusion Criteria

• Age ≥ 18 years old;
• Gastrointestinal (GI) mucosal or submucosal lesions detected by general endoscopy;
• Require small-probe ultrasonic endoscopy (mEUS) under sedation for definitive diagnosis;
• Clearly understand the study and voluntarily participate, with informed consent provided.

Exclusion Criteria

• Failure to meet the requirements for mEUS examination and anaesthesia, or need to use multiple sedative and analgesic drugs;
• Pregnancy or breastfeeding;
• Chronic use of opioids and benzodiazepines;
• Structural changes in the GI tract caused by abdominal surgery;
• Presence of mental illness;
• Presence of lesions in the oesophagus.

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Prospective

Number of groups / cohorts

3

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Low temperature group; The temperature is 6℃-10℃.	Other: Change the water injection temperature; Water injection is a routine procedure for endoscopy of small probe ultrasound, and our intervention is to change the water temperature and observe the effects of different water temperatures on patient safety and comfort.
room temperature group; The temperature is 20℃-24℃.	Other: Change the water injection temperature; Water injection is a routine procedure for endoscopy of small probe ultrasound, and our intervention is to change the water temperature and observe the effects of different water temperatures on patient safety and comfort.
Core temperature group; The temperature is 35℃-39℃.	Other: Change the water injection temperature; Water injection is a routine procedure for endoscopy of small probe ultrasound, and our intervention is to change the water temperature and observe the effects of different water temperatures on patient safety and comfort.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
mEUS image quality	Assessed by two independent experts (excluding the operating endoscopist) using Soon's scoring method on a 1-5 scale: 1 = air artifact obscures target lesion; 2 = air artifact severely impairs lesion size/characteristic assessment; 3 = air artifact mildly impairs lesion size/characteristic assessment; 4 = air artifact present but does not compromise lesion assessment; 5 = no air artifact with unimpaired lesion assessment. Scores 1-2 = poor, 3-4 = good, 5 = excellent.	From examination initiation through 24 hours post-examination
mEUS diagnostic accuracy	Gold standard confirmation: surgical, ESD or puncture histopathological results for patients with tissue specimens; ≥6-month clinical follow-up (based on manifestations, test results, lesion size and echogenic changes) for determining benign/malignant nature in other patients.	Up to 6 months after mEUS examination

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Gastrointestinal (GI) peristaltic grade	Assessed by two independent experts (excluding the operating endoscopist) via recorded video, using Hiki's upper GI peristaltic score and Likman Mui's lower GI peristaltic score (1=no peristalsis; 5=markedly vigorous peristalsis).	During mEUS examination
Haemodynamic indices	Includes mean arterial pressure (MAP), heart rate (HR), and oxygen saturation (SpO2); measured at 6 time points: anaesthesia assessment (T0), endoscopy (T1), before water infusion (T2), at water infusion (T3), after total water aspiration (T4), and at wakefulness (T5).	At T0, T1, T2, T3, T4, and T5 time points
Adverse events	Includes coughing, choking, aspiration, hypotension (MAP during/after water infusion <20% of pre-infusion level), bradycardia (HR <50 beats/min), tachycardia (HR >100 beats/min), hypoxaemia (SpO2 <90%), bleeding, perforation, and infection.	Periprocedural (from anesthesia assessment to post-anesthesia wakefulness)
Somatic and psychological feeling scores	Assessed via questionnaire post-anesthesia recovery: somatic discomfort (nausea/vomiting, bloating, coldness, anxiety); pain (VAS: 0=no pain to 10=severe pain); comfort and satisfaction (5-point Likert scale: 1=very uncomfortable/dissatisfied to 5=very comfortable/satisfied).	Post-anesthesia recovery (Day 1)

Collaborators and Investigators

• Sponsor: The Third Xiangya Hospital of Central South University
• Investigators: Study Chair: L Tian, The Third Xiangya Hospital of Central South University

Study record dates

Study Major Dates

• Study Start (Actual): June 14, 2022
• Primary Completion (Actual): May 1, 2023
• Study Completion (Actual): June 30, 2023

Study Registration Dates

• First Submitted: June 12, 2022
• First Submitted That Met QC Criteria: July 8, 2022
• First Posted (Actual): July 12, 2022

Study Record Updates

• Last Update Posted (Actual): December 26, 2025
• Last Update Submitted That Met QC Criteria: December 19, 2025
• Last Verified: July 1, 2022

More Information

Terms related to this study

• Other Study ID Numbers: fu3tianli

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: There is not a plan to make IPD available.

Drug and device information, study documents

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