SurgeryNCT05552092
Optimal Depth for Esophageal Stethoscope
A study testing Esophageal temperature monitoring according to the depth and Anatomical landmark in people with Surgery, run by Chosun University Hospital at 1 site in South Korea.
Trial summary
The purpose of the present study was to evaluate the optimal insertion depth of an esophageal stethoscope with a thermistor for core temperature monitoring. Read more about this study
- Who is it for?
- Ages 20 to 65 years
- Conditions the study is for
- Surgery
- What is being tested?
- Esophageal temperature monitoring according to the depth and Anatomical landmark
- Type of treatment
- Medical device
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 40 participants
- Where
- 1 siteSouth Korea
- Study dates
- 26 Nov 2022to 13 Jul 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 20 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- The patients with ASA class 1-2 (20-65 years old) who are undergoing elective surgery with supine or lithotomy position, without position change scheduled to last more than 90 min.
Who cannot join
- anatomical abnormality with the upper airway
- risks of a difficult airway
- abnormal central anatomical structures such as airway, diaphragm, or spine on the chest X-ray
- history of disease or surgery on the stomach or esophagus
- risks of bleeding or coagulopathy on the preoperative laboratory results
- obese patients with BMI over 30
Show all 10Show fewer
- contraindication to insertion of ES for the surgery
- who did not take a standing chest PA X-ray before surgery
- position change during the surgery
- open chest surgery
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Optimal Depth for Esophageal Stethoscope for the Monitoring of Core Temperature
The purpose of the present study was to evaluate the optimal insertion depth of an esophageal stethoscope with a thermistor for core temperature monitoring.
Read the detailed description
Monitoring core temperature is crucial for maintaining normothermia during general anesthesia. During anesthesia, an esophageal stethoscope with a thermistor for monitoring esophageal temperature is frequently used.
There are several researches on the depth or position of the esophageal stethoscopes, but there is only limited information (known as about 40-45 cm or T8-T9).
The purpose of the present study was to evaluate the optimal insertion depth of an esophageal stethoscope with a thermistor for core temperature monitoring.
- Conditions
- Surgery
- Being tested
- Esophageal temperature monitoring according to the depth, Anatomical landmark
- Keywords
- Anatomic Landmarks, Body Temperature, Monitoring, Intraoperative
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Esophageal temperature monitoring according to the depthDevice
Core temperatures will be measured with a tympanic thermometer as a reference. When the tympanic membrane (TM) temperature is constant after measuring three consecutive times at 10 seconds intervals, the temperature will be assumed as the core body temperature.
Initially, the esophageal stethoscope (ES) will be inserted to a depth of 45 cm from the incisor. After 30 minutes of monitoring, when the changes in the body temperatures stabilized, initial temperatures of the TM and ES thermistor will be assessed.
After 5 minutes, ES will be taken out 2 cm back, and the temperatures of each site will be measured when the temperature change of the ES thermistor stabilized below 0.1°C. Eventually, the depth of ES will be changed from 45 to 27 cm with a 2 cm interval, and the temperature at each position will be measured.
Anatomical landmarkOther
For the further evaluation of the optimal insertion depth of GDT, anatomical landmarks such as distance from the cricoid cartilage to the carina (CCD) and distance from the carina to the intervertebral disc between T8 and T9 (CDD) will be measured using an electronic caliper on a preoperative chest X-ray.
| Study group | Role | What they receive |
|---|---|---|
| Experimental | Experimental | The patients with ASA class 1-2 (20-65 years old) who are undergoing elective surgery with supine or lithotomy position, without position change, scheduled to last more than 90 min. Receives: Device: Esophageal temperature monitoring according to the depth; Other: Anatomical landmark |
What is being measured
The primary outcome is the main question the study is designed to answer.
Desired insertion depth of ES thermistor
To evaluate the desired insertion depth, we will assess the accuracy of temperatures of the ES thermistor at each location by estimating the difference between the esophageal temperature using ES thermistor and the core body temperatures of TM.
Measured: 1 day
Secondary outcomes (2)
Correlation analysis
The secondary outcome of the study is to assess the correlation between the characteristics of patients including gender, height, weight, BMI, CCD, or CDD, and the actual insertion depth of the ES which showed the most minor difference in temperature between TM and ES thermistor.
Radiographic landmarks On the preoperative chest radiograph, the cricoid-to-carina distance (CCD) and the carina-to-T8/9-intervertebral-disc distance (CDD) will be measured.
Measured: Through study completion, 1 year
Optimal depth analysis
We will calculate a mathematical model to predict the optimal insertion depth of ES for the esophageal temperature monitoring, and further analysis for the accuracy and correlation will be done.
To quantify tolerance to positioning error, the difference was modeled as a quadratic function of the offset from the MHS position (depth - MHS) using a linear mixed-effects model with a random intercept per patient. From the fixed-effect curve and the total (within- plus between-patient) standard deviation, the probability that a single reading fell within ±0.5 °C of core was computed across offsets to define ≥90% and ≥85% "safe zones."
Measured: Through study completion, 1 year
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted23 Sep 2022
- Study start26 Nov 2022
- Primary completion13 Jul 2026
- Study completion13 Jul 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for SurgeryStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Other
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Enrolment
- 40 participants (actual)
Sponsor and investigators
- Lead sponsor
- Chosun University Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Ki Tae Jung, Chosun University Hospital
- Investigators
- Ki Tae Jun, M.D., Ph.D., Study director, Chosun University Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05552092
- Sponsor's protocol ID
- ET_Position
- Status last verified
- Mar 2026
- First submitted
- 14 Sep 2022
- Last updated
- 21 Jul 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Wang M, Singh A, Qureshi H, Leone A, Mascha EJ, Sessler DI. Optimal Depth for Nasopharyngeal Temperature Probe Positioning. Anesth Analg. 2016 May;122(5):1434-8. doi: 10.1213/ANE.0000000000001213.
PubMed 26974019
Study at a glance
From the registry record, last updated by the sponsor on 21 Jul 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Optimal Depth for Esophageal Stethoscope for the Monitoring of Core Temperature
- ClinicalTrials.gov ID
- NCT05552092
- Acronym / sponsor ID
- ET_Position
- Conditions
- Surgery
- Keywords
- Anatomic Landmarks, Body Temperature, Monitoring, Intraoperative
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 40 participants (actual)
- Lead sponsor
- Chosun University HospitalUniversity, hospital or other
- Study start
- 26 Nov 2022 (actual)
- Primary completion
- 13 Jul 2026 (actual)
- Study completion
- 13 Jul 2026 (actual)
- First posted
- 23 Sep 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of the present study was to evaluate the optimal insertion depth of an esophageal stethoscope with a thermistor for core temperature monitoring.
Detailed description
Monitoring core temperature is crucial for maintaining normothermia during general anesthesia. During anesthesia, an esophageal stethoscope with a thermistor for monitoring esophageal temperature is frequently used.
There are several researches on the depth or position of the esophageal stethoscopes, but there is only limited information (known as about 40-45 cm or T8-T9).
The purpose of the present study was to evaluate the optimal insertion depth of an esophageal stethoscope with a thermistor for core temperature monitoring.
Study design
- Primary purpose
- Other
- Allocation
- Not applicable
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Experimental | Experimental | Device: Esophageal temperature monitoring according to the depth, Other: Anatomical landmarkThe patients with ASA class 1-2 (20-65 years old) who are undergoing elective surgery with supine or lithotomy position, without position change, scheduled to last more than 90 min. |
Who may qualify
- Ages
- 20 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (1 listed)
- The patients with ASA class 1-2 (20-65 years old) who are undergoing elective surgery with supine or lithotomy position, without position change scheduled to last more than 90 min.
Key exclusion criteria (10 listed)
- anatomical abnormality with the upper airway
- risks of a difficult airway
- abnormal central anatomical structures such as airway, diaphragm, or spine on the chest X-ray
- history of disease or surgery on the stomach or esophagus
- risks of bleeding or coagulopathy on the preoperative laboratory results
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Esophageal temperature monitoring according to the depthCore temperatures will be measured with a tympanic thermometer as a reference. When the tympanic membrane (TM) temperature is constant after measuring three consecutive times at 10 seconds intervals, the temperature will be assumed as the core body temperature. Initially, the esophageal stethoscope (ES) will be inserted to a depth of 45 cm from the incisor. After 30 minutes of monitoring, when the changes in the body temperatures stabilized, initial temperatures of the TM and ES thermistor will be assessed. After 5 minutes, ES will be taken out 2 cm back, and the temperatures of each site will be measured when the temperature change of the ES thermistor stabilized below 0.1°C. Eventually, the depth of ES will be changed from 45 to 27 cm with a 2 cm interval, and the temperature at each position will be measured. | Device | Experimental |
| Anatomical landmarkFor the further evaluation of the optimal insertion depth of GDT, anatomical landmarks such as distance from the cricoid cartilage to the carina (CCD) and distance from the carina to the intervertebral disc between T8 and T9 (CDD) will be measured using an electronic caliper on a preoperative chest X-ray. | Other | Experimental |
Primary outcome
Desired insertion depth of ES thermistor
Time frame: 1 day
To evaluate the desired insertion depth, we will assess the accuracy of temperatures of the ES thermistor at each location by estimating the difference between the esophageal temperature using ES thermistor and the core body temperatures of TM.
2 secondary outcomes
Correlation analysis
Time frame: Through study completion, 1 year
Optimal depth analysis
Time frame: Through study completion, 1 year
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 21 Jul 2026.
- Results publication: PubMed 26974019Wang M, Singh A, Qureshi H, Leone A, Mascha EJ, Sessler DI. Optimal Depth for Nasopharyngeal Temperature Probe Positioning. Anesth Analg. 2016 May;122(5):1434-8. doi: 10.1213/ANE.0000000000001213.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Ki Tae Jun, M.D., Ph.D. study director
Chosun University Hospital
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Esophageal temperature monitoring according to the depth and Anatomical landmark in people with Surgery, run by Chosun University Hospital at 1 site in South Korea.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 10 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 21 Jul 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in South Korea. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Desired insertion depth of ES thermistor (time frame: 1 day). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05552092, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 21 Jul 2026.