ENDOBRONCHIAL ULTRASOUND - TRANSBRONCHIAL NEEDLE ASPIRATIONNCT07587736
The Role of Ultrasonographic Tracheal Measurements in Predicting Hypoxemia During Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration
An observational study of ENDOBRONCHIAL ULTRASOUND - TRANSBRONCHIAL NEEDLE ASPIRATION and Hypoxemia, run by Ankara Ataturk Sanatorium Training and Research Hospital at 1 site in Turkey (Türkiye).
Trial summary
Bronchoscopic procedures performed under endobronchial ultrasound (EBUS) guidance are widely used minimally invasive diagnostic methods for the evaluation of mediastinal lymph nodes. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- ENDOBRONCHIAL ULTRASOUND - TRANSBRONCHIAL NEEDLE ASPIRATION, Hypoxemia, Trachea
- What is being tested?
- TRACHEAL DIAMETER MEASUREMENT and Hypoxemia
- How many people
- 300 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 20 Nov 2026to 1 May 2027
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
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 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: This study will be conducted in accordance with the Declaration of Helsinki and will be carried out at SBÜ Ankara Atatürk Sanatoryum Training and Research Hospital. In patients aged 18 years and older scheduled to undergo EBUS-TBNA, the narrowest pre-procedural tracheal diameter will be determined. The relationship between tracheal diameter and the development of hypoxemia will be analyzed.
Who may be able to join
- Patients scheduled for elective EBUS-TBNA
- Patients who provide written informed consent
- Patients with ASA physical status I-III
- Patients aged ≥18 years
Who cannot join
- Tracheal stenosis or significant airway obstruction
- History of tracheostomy
- Use of home oxygen therapy
- Pre-procedural SpO₂ < 90% on room air
- History of prior thoracic surgery
- Diagnosis of congestive heart failure
Show all 17Show fewer
- Presence of pleural effusion
- FEV1 < 40%
- COPD patients classified as GOLD stage 3-4
- Restrictive lung disease (FVC < 50%)
- Advanced pulmonary hypertension
- History of surgery affecting neck anatomy
- Tracheal deviation due to large thyroid or mediastinal mass
- ASA physical status IV
- Pregnancy
- EBUS performed under general anesthesia (with endotracheal intubation or laryngeal mask airway)
- Hemodynamic instability
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Turkey (Türkiye)1 site
Ankara Ataturk Sanatorium Training and Research Hospital, Ankara, 06280
Ankara
About this study
Official title: The Role of Ultrasonographic Tracheal Measurements in Predicting Hypoxemia During Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration: A Prospective Observational Study
Bronchoscopic procedures performed under endobronchial ultrasound (EBUS) guidance are widely used minimally invasive diagnostic methods for the evaluation of mediastinal lymph nodes. Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration (EBUS-TBNA) is an indicated procedure for the diagnosis, staging, and histopathological characterization of primary or metastatic tumors. The procedure is generally performed under moderate or deep sedation to enhance patient comfort and optimize procedural success. Deep sedation has been shown to be a safe and effective approach in terms of respiratory complications in both younger and elderly patients.
However, hypoxemia may develop during EBUS procedures due to mechanisms such as mechanical airway obstruction, sedation-related ventilatory depression, and ventilation-perfusion mismatch. A decrease in oxygen saturation is frequently observed during bronchoscopic procedures, with reported rates of up to 94%. Studies have also reported a hypoxemia rate of approximately 25% during EBUS, even with the use of a nasopharyngeal oxygen cannula. Therefore, maintaining adequate oxygenation throughout the procedure is of critical importance. In patients receiving sedation under spontaneous respiration, oxygen support is typically provided via low-flow systems such as nasal cannulae, which can generally deliver flows of up to 15 L/min.
Read more
It has been reported that a fiberoptic bronchoscope occupies approximately 10% of the tracheal cross-sectional area and about 15% at the level of the cricoid ring, leading to partial obstruction. EBUS endoscopes have a larger outer diameter and, in addition, may exert more pronounced negative effects on respiratory mechanics due to the balloon mechanism used. The outer diameter of EBUS bronchoscopes typically ranges between 6.2 and 6.7 mm, mechanically occupying a significant portion of the tracheal lumen. This may restrict tracheal airflow, leading to partial obstruction and consequently predisposing to hypoxemia. Therefore, identifying objective anatomical predictors that can predict the development of hypoxemia is of clinical importance. However, to the best of our knowledge, no study in the literature has statistically investigated the relationship between tracheal measurements and hypoxemia occurring during EBUS.
In this study, the investigators aim to investigate the relationship between pre-procedural tracheal diameter measured by ultrasonography (USG) and the EBUS outer diameter/tracheal diameter ratio (airway occupancy ratio) with the development of hypoxemia during the procedure in patients undergoing EBUS-TBNA. Additionally, it is aimed to determine the optimal tracheal diameter cutoff value that may predict the development of hypoxemia.
Study Design and Patient Population This study will be conducted in accordance with the Declaration of Helsinki and will be carried out at SBÜ Ankara Atatürk Sanatoryum Training and Research Hospital after obtaining approval from the institutional ethics committee. The study is planned as a prospective observational cohort study. Adult patients scheduled to undergo EBUS-TBNA will be included.
The following parameters will be recorded:
- Age
- Sex
- Body mass index (BMI)
- FEV1 value
- Baseline SpO₂
- Lowest recorded SpO₂
- Systolic/diastolic/mean arterial blood pressure and heart rate measured at 10-minute intervals during the procedure
- Sedative drug doses
- Procedure duration
- Tracheal diameter measured by ultrasonography (USG)
- Airway occupancy ratio (EBUS outer diameter / narrowest tracheal diameter measured by USG)
- Duration and total number of hypoxic episodes during the procedure
- Requirement for airway interventions (jaw thrust, mask ventilation, intubation, etc.)
- Whether nasal oxygen flow was increased in case of hypoxemia, and if so, by how many L/min
- Presence of cough, hiccups, secretions requiring aspiration, bronchospasm, and procedure-related bleeding
- Whether the procedure was interrupted
Read the detailed description
H0: There is no significant association between ultrasonographic tracheal measurements and the development of hypoxemia during Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration (EBUS-TBNA).
H1: There is a significant association between ultrasonographic tracheal measurements and the development of hypoxemia during Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration (EBUS-TBNA).
Ultrasonographic Measurements In this study, tracheal diameter will be measured using a high-frequency linear probe while the patient is in the supine position with the neck in a neutral position. Patients will be instructed to take a deep inspiration, and measurements will be obtained during inspiration at the level just below the cricoid cartilage and at the level of the 2nd-3rd tracheal rings. The narrowest transverse tracheal diameter will be recorded. All ultrasonographic measurements will be performed by the same anesthesiologist.
Sedation Protocol Patients will receive 4 L/min oxygen via nasal cannula along with routine hemodynamic monitoring. Sedation will be administered according to the standard protocol routinely used in our clinic. During the procedure, patients will be maintained under deep sedation corresponding to a Richmond Agitation-Sedation Scale (RASS) score of -4. The total doses of sedative agents used will be recorded.
- Being tested
- TRACHEAL DIAMETER MEASUREMENT, Hypoxemia
- Keywords
- ENDOBRONCHIAL ULTRASOUND, TRANSBRONCHIAL NEEDLE ASPIRATION, TRACHEAL DIAMETER, HYPOXEMİA
- Medical subject headings
- Hypoxia, Tracheal Diseases
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
TRACHEAL DIAMETER MEASUREMENTOther
"In patients aged 18 years and older scheduled to undergo EBUS-TBNA, the narrowest pre-procedural tracheal diameter will be determined. The relationship between tracheal diameter and the development of hypoxemia will be analyzed.
HypoxemiaOther
Hypoxemia will be defined as the presence of at least one of the following criteria:
- SpO₂ < 90% for at least 10 seconds, or
- A decrease in SpO₂ of ≥5% from baseline
| Study group | Role | What they receive |
|---|---|---|
| Adult patients scheduled to undergo EBUS-TBNA | "In patients aged 18 years and older scheduled to undergo EBUS-TBNA, the narrowest pre-procedural tracheal diameter will be determined. The relationship between tracheal diameter and the development of hypoxemia will be analyzed. Receives: Other: TRACHEAL DIAMETER MEASUREMENT; Other: Hypoxemia |
What is being measured
The primary outcome is the main question the study is designed to answer.
Hypoxemia
Measured: Periprocedural
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted14 May 2026
- Study start20 Nov 2026 (estimated)
- Primary completion1 May 2027 (estimated)
- Study completion1 May 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for ENDOBRONCHIAL ULTRASOUND - TRANSBRONCHIAL NEEDLE ASPIRATIONStudies 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
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 300 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Ankara Ataturk Sanatorium Training and Research Hospital
- Sponsor type
- Other government
- Responsible party
- Principal investigator, Ramazan Baldemir, Ankara Ataturk Sanatorium Training and Research Hospital
- Investigators
- Ramazan BALDEMİR, Principal investigator, ANKARA ATATURK SANATORİUM TRAİNİNG AND RESEARCH HOSPITAL
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07587736
- Sponsor's protocol ID
- 2024-BÇEK/544
- Status last verified
- May 2026
- First submitted
- 27 Apr 2026
- Last updated
- 4 Nov 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 4 Nov 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Role of Ultrasonographic Tracheal Measurements in Predicting Hypoxemia During Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration: A Prospective Observational Study
- ClinicalTrials.gov ID
- NCT07587736
- Acronym / sponsor ID
- 2024-BÇEK/544
- Keywords
- ENDOBRONCHIAL ULTRASOUND, TRANSBRONCHIAL NEEDLE ASPIRATION, TRACHEAL DIAMETER, HYPOXEMİA
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 300 participants (estimated)
- Lead sponsor
- Ankara Ataturk Sanatorium Training and Research HospitalOther government
- Study start
- 20 Nov 2026 (estimated)
- Primary completion
- 1 May 2027 (estimated)
- Study completion
- 1 May 2027 (estimated)
- First posted
- 14 May 2026 (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.
Bronchoscopic procedures performed under endobronchial ultrasound (EBUS) guidance are widely used minimally invasive diagnostic methods for the evaluation of mediastinal lymph nodes. Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration (EBUS-TBNA) is an indicated procedure for the diagnosis, staging, and histopathological characterization of primary or metastatic tumors. The procedure is generally performed under moderate or deep sedation to enhance patient comfort and optimize procedural success. Deep sedation has been shown to be a safe and effective approach in terms of respiratory complications in both younger and elderly patients.
However, hypoxemia may develop during EBUS procedures due to mechanisms such as mechanical airway obstruction, sedation-related ventilatory depression, and ventilation-perfusion mismatch. A decrease in oxygen saturation is frequently observed during bronchoscopic procedures, with reported rates of up to 94%. Studies have also reported a hypoxemia rate of approximately 25% during EBUS, even with the use of a nasopharyngeal oxygen cannula. Therefore, maintaining adequate oxygenation throughout the procedure is of critical importance. In patients receiving sedation under spontaneous respiration, oxygen support is typically provided via low-flow systems such as nasal cannulae, which can generally deliver flows of up to 15 L/min.
It has been reported that a fiberoptic bronchoscope occupies approximately 10% of the tracheal cross-sectional area and about 15% at the level of the cricoid ring, leading to partial obstruction. EBUS endoscopes have a larger outer diameter and, in addition, may exert more pronounced negative effects on respiratory mechanics due to the balloon mechanism used. The outer diameter of EBUS bronchoscopes typically ranges between 6.2 and 6.7 mm, mechanically occupying a significant portion of the tracheal lumen. This may restrict tracheal airflow, leading to partial obstruction and consequently predisposing to hypoxemia. Therefore, identifying objective anatomical predictors that can predict the development of hypoxemia is of clinical importance. However, to the best of our knowledge, no study in the literature has statistically investigated the relationship between tracheal measurements and hypoxemia occurring during EBUS.
In this study, the investigators aim to investigate the relationship between pre-procedural tracheal diameter measured by ultrasonography (USG) and the EBUS outer diameter/tracheal diameter ratio (airway occupancy ratio) with the development of hypoxemia during the procedure in patients undergoing EBUS-TBNA. Additionally, it is aimed to determine the optimal tracheal diameter cutoff value that may predict the development of hypoxemia.
Study Design and Patient Population This study will be conducted in accordance with the Declaration of Helsinki and will be carried out at SBÜ Ankara Atatürk Sanatoryum Training and Research Hospital after obtaining approval from the institutional ethics committee. The study is planned as a prospective observational cohort study. Adult patients scheduled to undergo EBUS-TBNA will be included.
The following parameters will be recorded:
- Age
- Sex
- Body mass index (BMI)
- FEV1 value
- Baseline SpO₂
- Lowest recorded SpO₂
- Systolic/diastolic/mean arterial blood pressure and heart rate measured at 10-minute intervals during the procedure
- Sedative drug doses
- Procedure duration
- Tracheal diameter measured by ultrasonography (USG)
- Airway occupancy ratio (EBUS outer diameter / narrowest tracheal diameter measured by USG)
- Duration and total number of hypoxic episodes during the procedure
- Requirement for airway interventions (jaw thrust, mask ventilation, intubation, etc.)
- Whether nasal oxygen flow was increased in case of hypoxemia, and if so, by how many L/min
- Presence of cough, hiccups, secretions requiring aspiration, bronchospasm, and procedure-related bleeding
- Whether the procedure was interrupted
Detailed description
H0: There is no significant association between ultrasonographic tracheal measurements and the development of hypoxemia during Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration (EBUS-TBNA).
H1: There is a significant association between ultrasonographic tracheal measurements and the development of hypoxemia during Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration (EBUS-TBNA).
Ultrasonographic Measurements In this study, tracheal diameter will be measured using a high-frequency linear probe while the patient is in the supine position with the neck in a neutral position. Patients will be instructed to take a deep inspiration, and measurements will be obtained during inspiration at the level just below the cricoid cartilage and at the level of the 2nd-3rd tracheal rings. The narrowest transverse tracheal diameter will be recorded. All ultrasonographic measurements will be performed by the same anesthesiologist.
Sedation Protocol Patients will receive 4 L/min oxygen via nasal cannula along with routine hemodynamic monitoring. Sedation will be administered according to the standard protocol routinely used in our clinic. During the procedure, patients will be maintained under deep sedation corresponding to a Richmond Agitation-Sedation Scale (RASS) score of -4. The total doses of sedative agents used will be recorded.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Adult patients scheduled to undergo EBUS-TBNA | – | Other: TRACHEAL DIAMETER MEASUREMENT, Other: Hypoxemia"In patients aged 18 years and older scheduled to undergo EBUS-TBNA, the narrowest pre-procedural tracheal diameter will be determined. The relationship between tracheal diameter and the development of hypoxemia will be analyzed. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- This study will be conducted in accordance with the Declaration of Helsinki and will be carried out at SBÜ Ankara Atatürk Sanatoryum Training and Research Hospital. In patients aged 18 years and older scheduled to undergo EBUS-TBNA, the narrowest pre-procedural tracheal diameter will be determined. The relationship between tracheal diameter and the development of hypoxemia will be analyzed.
Key inclusion criteria (4 listed)
- Patients scheduled for elective EBUS-TBNA
- Patients who provide written informed consent
- Patients with ASA physical status I-III
- Patients aged ≥18 years
Key exclusion criteria (17 listed)
- Tracheal stenosis or significant airway obstruction
- History of tracheostomy
- Use of home oxygen therapy
- Pre-procedural SpO₂ < 90% on room air
- History of prior thoracic surgery
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 |
|---|---|---|
| TRACHEAL DIAMETER MEASUREMENT"In patients aged 18 years and older scheduled to undergo EBUS-TBNA, the narrowest pre-procedural tracheal diameter will be determined. The relationship between tracheal diameter and the development of hypoxemia will be analyzed. | Other | Adult patients scheduled to undergo EBUS-TBNA |
| HypoxemiaHypoxemia will be defined as the presence of at least one of the following criteria: * SpO₂ < 90% for at least 10 seconds, or * A decrease in SpO₂ of ≥5% from baseline | Other | Adult patients scheduled to undergo EBUS-TBNA |
Primary outcome
Hypoxemia
Time frame: Periprocedural
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 4 Nov 2026.
- 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.
Ramazan BALDEMİR principal investigator
ANKARA ATATURK SANATORİUM TRAİNİNG AND RESEARCH HOSPITAL
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of ENDOBRONCHIAL ULTRASOUND - TRANSBRONCHIAL NEEDLE ASPIRATION and Hypoxemia, run by Ankara Ataturk Sanatorium Training and Research Hospital at 1 site in Turkey (Türkiye).
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 4 inclusion and 17 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: opening soon, as of the sponsor's last update on 4 Nov 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 Turkey (Türkiye). 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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Ramazan BALDEMİR (+905303570166, baldemir2323@gmail.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Hypoxemia (time frame: Periprocedural). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 4 Nov 2026.