UltrasonographyNCT07243106
Airway Ultrasound vs Clinical Predictors for Difficult Airway
An observational study of Ultrasonography and Difficult Airway, run by Tokat Gaziosmanpasa University at 1 site in Turkey (Türkiye).
Trial summary
This prospective observational study aims to evaluate the diagnostic value of airway ultrasonography in predicting difficult intubation in adult patients undergoing elective surgery under general anesthesia. Read more about this study
- Who is it for?
- Ages 18 to 60 yearsHealthy volunteers can take part
- Conditions the study is for
- Ultrasonography, Difficult Airway, Preoperative Evaluation
- How many people
- 140 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 20 Dec 2025to 1 Dec 2026
- 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 to 60 years
- All sexes
- Healthy volunteers accepted
- Adult
Study population: Adult patients aged 18-60 years, classified as ASA I-III, scheduled for elective surgery under general anesthesia with planned endotracheal intubation. Both male and female patients meeting inclusion criteria and without any exclusion criteria (emergency surgery, known difficult intubation, head/neck trauma, prior head/neck surgery or malignancy, pregnancy) will be eligible for enrollment.
Who may be able to join
- Adult patients aged 18-60 years
- Scheduled for elective surgery
- ASA (American Society of Anesthesiologists) physical status I, II, or III
- Planned for endotracheal intubation under general anesthesia
Who cannot join
- Patients requiring emergency surgery
- Patients with a known history of difficult intubation
- Patients with head or neck trauma
- Patients with a history of previous head or neck surgery or head/neck malignancy
- Pregnant patients
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
Tokat Gaziosmanpasa University
Tokat Province, Tokat Province, 60100
About this study
Official title: Role of Airway Ultrasonography in Predicting Difficult Airway: Comparison of Clinical and Sonographic Parameters
This prospective observational study aims to evaluate the diagnostic value of airway ultrasonography in predicting difficult intubation in adult patients undergoing elective surgery under general anesthesia. Preoperative sonographic measurements of upper airway structures will be compared with conventional clinical airway assessment parameters such as the Mallampati score, thyromental distance, and sternomental distance.
The study seeks to determine whether ultrasonographic measurements can serve as independent predictors of difficult airway and whether combining them with clinical parameters improves diagnostic accuracy. Additionally, the correlation between sonographic findings and the Intubation Difficulty Scale (IDS) will be analyzed to assess the potential clinical utility of airway ultrasound in preoperative airway evaluation.
Read the detailed description
Airway management is one of the most critical and potentially life-threatening procedures in anesthesiology practice. Difficult intubation may result in severe morbidity and mortality if not promptly and effectively managed. Therefore, reliable preoperative prediction of a difficult airway is crucial for ensuring patient safety and optimizing perioperative outcomes.
Traditional clinical assessment methods-such as the Mallampati classification, thyromental distance, and sternomental distance-are commonly used to predict difficult airway. However, these predictors have limited sensitivity and specificity, and their diagnostic accuracy may vary depending on operator experience and subjective interpretation.
In recent years, ultrasonography has gained increasing acceptance in anesthesiology as a non-invasive, rapid, inexpensive, and real-time imaging technique. Airway ultrasonography enables direct visualization of individual anatomical variations in the upper airway, providing more objective and reproducible data for airway assessment.
The primary objective of this study is to determine the diagnostic performance of ultrasonographic parameters obtained from preoperative airway ultrasound in predicting difficult laryngoscopy and intubation, and to compare them with conventional clinical assessment methods. The study will also evaluate whether ultrasonographic measurements are independent predictors of difficult airway and whether combining sonographic and clinical parameters enhances overall diagnostic accuracy.
Furthermore, the relationship between ultrasound-based anatomical measurements and the Intubation Difficulty Scale (IDS) will be analyzed. This correlation aims to demonstrate the potential contribution of airway ultrasonography to clinical decision-making and its possible role in improving airway safety in anesthetic practice.
Hypotheses:
H0 (Null Hypothesis): Airway ultrasonography does not provide higher diagnostic accuracy than traditional clinical assessment methods in predicting difficult intubation and has no significant correlation with the Intubation Difficulty Scale (IDS).
H1 (Alternative Hypothesis): Airway ultrasonography provides higher diagnostic accuracy than traditional clinical assessment methods in predicting difficult intubation and is significantly correlated with the Intubation Difficulty Scale (IDS).
- Conditions
- Ultrasonography, Difficult Airway, Preoperative Evaluation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Adult patients scheduled for elective surgery under general anesthesia with endotracheal intubation | Demographic data of all participants-including age, sex, type of planned surgery, ASA physical status, and comorbidities-will be recorded. Before induction of anesthesia, all patients will be evaluated using standard clinical airway assessment parameters. These include the Mallampati score, thyromental distance, sternomental distance, neck circumference, and upper lip bite test. Body mass index (BMI) and waist-to-hip ratio will also be measured and documented. In the preoperative period, all patients will undergo airway ultrasonography performed by an anesthesiologist. Sonographic assessments will be carried out by a single experienced anesthesiologist using a linear transducer, with the patient positioned in the sniffing position. The following ultrasound measurements will be obtained and recorded: Skin-to-epiglottis distance, skin-to-hyoid bone distance, skin-to-anterior commissure of the vocal cords distance, skin-to-trachea distance at the suprasternal notch level. |
What is being measured
The primary outcome is the main question the study is designed to answer.
The Intubation Difficulty Scale (IDS)
The Intubation Difficulty Scale (IDS) is a quantitative scoring system used to objectively assess the complexity of tracheal intubation. It incorporates seven parameters: number of intubation attempts, number of operators, number of alternative techniques used, Cormack-Lehane grade, lifting force required, necessity of external laryngeal pressure, and position of the vocal cords.
The total IDS score is calculated as the sum of these variables, providing a numerical indicator of intubation difficulty (IDS = 0 indicates easy intubation; IDS = 1-5 mild to moderate difficulty; IDS > 5 difficult intubation).
Measured: During tracheal intubation (approximately 1-3 minutes after induction of anesthesia)
Difficulty of mask ventilation
After standard induction of anesthesia, all patients will be ventilated via face mask for 2 minutes, followed by tracheal intubation using a Macintosh laryngoscope. The difficulty of mask ventilation will be assessed using the Han Mask Ventilation Scale, defined as follows:
Class 1: Mask ventilation possible
Class 2: Mask ventilation possible with the use of an oral airway or other adjuncts
Class 3: Mask ventilation possible only with the assistance of a second person
Class 4: Mask ventilation impossible
Measured: During 2-minute face mask ventilation after induction of anesthesia
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 Nov 2025
- Study start20 Dec 2025
- Primary completion1 Jun 2026
- Study completion1 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for UltrasonographyStudies 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
- Other
- Time perspective
- Other
- Enrolment
- 140 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Tokat Gaziosmanpasa University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Ali Genc, Tokat Gaziosmanpasa University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07243106
- Sponsor's protocol ID
- 25-MOBAEK-329
- Status last verified
- Oct 2026
- First submitted
- 17 Nov 2025
- Last updated
- 2 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: De-identified individual participant data will be shared with other researchers upon reasonable request
Study at a glance
From the registry record, last updated by the sponsor on 2 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Role of Airway Ultrasonography in Predicting Difficult Airway: Comparison of Clinical and Sonographic Parameters
- ClinicalTrials.gov ID
- NCT07243106
- Acronym / sponsor ID
- 25-MOBAEK-329
- Conditions
- Ultrasonography, Difficult Airway, Preoperative Evaluation
- Study type
- Observational
- Recruitment status
- Enrolling by invitation
- Enrolment
- 140 participants (estimated)
- Lead sponsor
- Tokat Gaziosmanpasa UniversityUniversity, hospital or other
- Study start
- 20 Dec 2025 (actual)
- Primary completion
- 1 Jun 2026 (actual)
- Study completion
- 1 Dec 2026 (estimated)
- First posted
- 21 Nov 2025 (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.
This prospective observational study aims to evaluate the diagnostic value of airway ultrasonography in predicting difficult intubation in adult patients undergoing elective surgery under general anesthesia. Preoperative sonographic measurements of upper airway structures will be compared with conventional clinical airway assessment parameters such as the Mallampati score, thyromental distance, and sternomental distance.
The study seeks to determine whether ultrasonographic measurements can serve as independent predictors of difficult airway and whether combining them with clinical parameters improves diagnostic accuracy. Additionally, the correlation between sonographic findings and the Intubation Difficulty Scale (IDS) will be analyzed to assess the potential clinical utility of airway ultrasound in preoperative airway evaluation.
Detailed description
Airway management is one of the most critical and potentially life-threatening procedures in anesthesiology practice. Difficult intubation may result in severe morbidity and mortality if not promptly and effectively managed. Therefore, reliable preoperative prediction of a difficult airway is crucial for ensuring patient safety and optimizing perioperative outcomes.
Traditional clinical assessment methods-such as the Mallampati classification, thyromental distance, and sternomental distance-are commonly used to predict difficult airway. However, these predictors have limited sensitivity and specificity, and their diagnostic accuracy may vary depending on operator experience and subjective interpretation.
In recent years, ultrasonography has gained increasing acceptance in anesthesiology as a non-invasive, rapid, inexpensive, and real-time imaging technique. Airway ultrasonography enables direct visualization of individual anatomical variations in the upper airway, providing more objective and reproducible data for airway assessment.
The primary objective of this study is to determine the diagnostic performance of ultrasonographic parameters obtained from preoperative airway ultrasound in predicting difficult laryngoscopy and intubation, and to compare them with conventional clinical assessment methods. The study will also evaluate whether ultrasonographic measurements are independent predictors of difficult airway and whether combining sonographic and clinical parameters enhances overall diagnostic accuracy.
Furthermore, the relationship between ultrasound-based anatomical measurements and the Intubation Difficulty Scale (IDS) will be analyzed. This correlation aims to demonstrate the potential contribution of airway ultrasonography to clinical decision-making and its possible role in improving airway safety in anesthetic practice.
Hypotheses:
H0 (Null Hypothesis): Airway ultrasonography does not provide higher diagnostic accuracy than traditional clinical assessment methods in predicting difficult intubation and has no significant correlation with the Intubation Difficulty Scale (IDS).
H1 (Alternative Hypothesis): Airway ultrasonography provides higher diagnostic accuracy than traditional clinical assessment methods in predicting difficult intubation and is significantly correlated with the Intubation Difficulty Scale (IDS).
Study design
- Observational model
- Other
- Time perspective
- Other
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Adult patients scheduled for elective surgery under general anesthesia with endotracheal intubation | – | –Demographic data of all participants-including age, sex, type of planned surgery, ASA physical status, and comorbidities-will be recorded. Before induction of anesthesia, all patients will be evaluated using standard clinical airway assessment parameters. These include the Mallampati score, thyromental distance, sternomental distance, neck circumference, and upper lip bite test. Body mass index (BMI) and waist-to-hip ratio will also be measured and documented. In the preoperative period, all patients will undergo airway ultrasonography performed by an anesthesiologist. Sonographic assessments will be carried out by a single experienced anesthesiologist using a linear transducer, with the patient positioned in the sniffing position. The following ultrasound measurements will be obtained and recorded: Skin-to-epiglottis distance, skin-to-hyoid bone distance, skin-to-anterior commissure of the vocal cords distance, skin-to-trachea distance at the suprasternal notch level. |
Who may qualify
- Ages
- 18 to 60 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
- Study population
- Adult patients aged 18-60 years, classified as ASA I-III, scheduled for elective surgery under general anesthesia with planned endotracheal intubation. Both male and female patients meeting inclusion criteria and without any exclusion criteria (emergency surgery, known difficult intubation, head/neck trauma, prior head/neck surgery or malignancy, pregnancy) will be eligible for enrollment.
Key inclusion criteria (4 listed)
- Adult patients aged 18-60 years
- Scheduled for elective surgery
- ASA (American Society of Anesthesiologists) physical status I, II, or III
- Planned for endotracheal intubation under general anesthesia
Key exclusion criteria (5 listed)
- Patients requiring emergency surgery
- Patients with a known history of difficult intubation
- Patients with head or neck trauma
- Patients with a history of previous head or neck surgery or head/neck malignancy
- Pregnant patients
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
The Intubation Difficulty Scale (IDS)
Time frame: During tracheal intubation (approximately 1-3 minutes after induction of anesthesia)
The Intubation Difficulty Scale (IDS) is a quantitative scoring system used to objectively assess the complexity of tracheal intubation. It incorporates seven parameters: number of intubation attempts, number of operators, number of alternative techniques used, Cormack-Lehane grade, lifting force required, necessity of external laryngeal pressure, and position of the vocal cords. The total IDS score is calculated as the sum of these variables, providing a numerical indicator of intubation difficulty (IDS = 0 indicates easy intubation; IDS = 1-5 mild to moderate difficulty; IDS > 5 difficult intubation).
Difficulty of mask ventilation
Time frame: During 2-minute face mask ventilation after induction of anesthesia
After standard induction of anesthesia, all patients will be ventilated via face mask for 2 minutes, followed by tracheal intubation using a Macintosh laryngoscope. The difficulty of mask ventilation will be assessed using the Han Mask Ventilation Scale, defined as follows: Class 1: Mask ventilation possible Class 2: Mask ventilation possible with the use of an oral airway or other adjuncts Class 3: Mask ventilation possible only with the assistance of a second person Class 4: Mask ventilation impossible
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 2 Oct 2026.
- Individual participant dataSharing planned: Yes. De-identified individual participant data will be shared with other researchers upon reasonable request
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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.
The record lists no contact. Use the official record to reach the sponsor.
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 Ultrasonography and Difficult Airway, run by Tokat Gaziosmanpasa University 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 5 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: enrolling by invitation, as of the sponsor's last update on 2 Oct 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?
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?
The Intubation Difficulty Scale (IDS) (time frame: During tracheal intubation (approximately 1-3 minutes after induction of anesthesia)). The study lists 2 primary outcomes in all. 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 2 Oct 2026.