Difficult IntubationNCT07383610
Ultrasound Predictors of Difficult Airway in Adults
An observational study of Difficult Intubation and Difficult Mask Ventilation, run by Kutahya Health Sciences University at 1 site in Turkey (Türkiye).
Trial summary
Difficult airway management is a major cause of perioperative complications. Standard bedside airway assessment tests may have limited ability to predict difficult intubation and difficult mask ventilation. Read more about this study
- Who is it for?
- Ages 18 to 70 yearsHealthy volunteers can take part
- Conditions the study is for
- Difficult Intubation, Difficult Mask Ventilation, Difficult Airway
- How many people
- 400 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 1 Oct 2023to 1 Oct 2024
- Phase
- Observational
- 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 18 to 70 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Study population: Adult patients aged 18-70 years (ASA I-III) scheduled for elective surgery under general anesthesia requiring orotracheal intubation
Who may be able to join
- Age 18-70 years
- ASA physical status I-III
- Elective surgery under general anesthesia requiring orotracheal intubation
- Written informed consent
Who cannot join
- Refusal to participate
- Emergency surgery
- Pregnancy
- Known upper airway pathology or previous airway surgery
- Restricted mouth opening (<3 cm)
- Cervical spine instability or significant limitation of neck mobility
Show all 11Show fewer
- Morbid obesity (BMI ≥40 kg/m²)
- Obstructive upper airway masses (e.g., head and neck tumors)
- Prior neck radiotherapy
- Clinically relevant neck masses
- Major facial/mandibular trauma or craniofacial anomalies
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Kütahya Health Sciences University
Kütahya, Kütahya, 3100
About this study
Official title: Investigation of Ultrasonographic Predictors of Difficult Intubation and Difficult Mask Ventilation in Adult Patients
Difficult airway management is a major cause of perioperative complications. Standard bedside airway assessment tests may have limited ability to predict difficult intubation and difficult mask ventilation. This prospective observational study aims to evaluate whether preoperative ultrasound measurements of airway structures (such as skin-to-epiglottis distance, tongue thickness, and pre-epiglottic space) can predict difficult intubation and difficult mask ventilation in adult patients undergoing surgery under general anesthesia.
Read the detailed description
This prospective observational cohort study was conducted to evaluate the predictive value of preoperative ultrasonographic airway measurements for difficult intubation and difficult mask ventilation in adult patients undergoing elective surgery under general anesthesia. A total of 400 patients aged 18-70 years with ASA physical status I-III were included. Before induction of anesthesia, standard clinical airway assessment tests were recorded, and ultrasound measurements were performed to assess airway-related anatomical structures. Ultrasonographic parameters included skin-to-epiglottis distance, skin-to-thyroid cartilage distance, thyroid cartilage-to-epiglottis distance, pre-epiglottic space depth, tongue thickness, and hyomental distance measurements.
Intraoperatively, mask ventilation and intubation conditions were documented. Difficult intubation was defined as requiring two or more intubation attempts. Difficult mask ventilation was defined as the need for two-handed mask ventilation or inability to ventilate adequately using a face mask. The primary objective was to determine the association between ultrasonographic measurements and difficult intubation
- Keywords
- Airway Ultrasonography, Ultrasound, Difficult Airway Prediction, Anesthesia
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 |
|---|---|---|
| Cohort 1: Adult patients undergoing surgery under general anesthesia | Adult patients (18-70 years, ASA I-III) scheduled for elective surgery under general anesthesia requiring orotracheal intubation. Preoperative clinical airway assessment and ultrasonographic airway measurements were recorded, and intraoperative intubation and mask ventilation outcomes were evaluated |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of Participants with Difficult Intubation
Difficult intubation was defined as requiring two or more intubation attempts (≥2 attempts) during induction of general anesthesia.
Measured: During induction of anesthesia (intraoperative)
Number of Participants with Difficult Mask Ventilation
Difficult mask ventilation was defined as the need for two-handed mask ventilation or inability to ventilate adequately using a face mask
Measured: During induction of anesthesia (intraoperative)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted3 Feb 2026
- Study start1 Oct 2023
- Primary completion1 Oct 2024
- Study completion1 Oct 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for Difficult IntubationStudies of the same condition, open and under way.
- More trials run by Kutahya Health Sciences UniversityThe sponsor's other registered studies.
- 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
- 400 participants (actual)
Sponsor and investigators
- Lead sponsor
- Kutahya Health Sciences University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Serkan TELLİ, Kutahya Health Sciences University
- Investigators
- Serkan Telli, MD, Principal investigator, Kutahya Health Sciences University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07383610
- Sponsor's protocol ID
- 2023/10-19
- Status last verified
- Jan 2026
- First submitted
- 26 Jan 2026
- Last updated
- 5 Feb 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data will not be shared due to institutional policies and to protect participant privacy and confidentiality.
Publications
1. Cook TM, MacDougall-Davis SR. Complications and failure of airway management. Br J Anaesth. 2012;109 Suppl 1(suppl 1):i68-i85. 2. Apfelbaum JL, Hagberg CA, Connis RT, Abdelmalak BB, Agarkar M, Dutton RP, et al. 2022 American Society of Anesthesiologists Practice Guidelines for Management of the Difficult Airway. Anesthesiology. 2022;136(1):31-81. 3. Roth D, Pace NL, Lee A, Hovhannisyan K, Warenits AM, Arrich J, et al. Airway physical examination tests for detection of difficult airway management in apparently normal adult patients. Cochrane Database Syst Rev. 2018;5(5):CD008874. 4. Shiga T, Wajima Z, Inoue T, Sakamoto A. Predicting difficult intubation in apparently normal patients: a meta-analysis of bedside screening test performance. Anesthesiology. 2005;103(2):429-37. 5. Detsky ME, Jivraj N, Adhikari NK, Friedrich JO, Pinto R, Simel DL, et al. Will This Patient Be Difficult to Intubate?: The Rational Clinical Examination Systematic Review. JAMA. 2019;321(5):493-503. 6. Singh M, Chin KJ, Chan VW, Wong DT, Prasad GA, Yu E. Use of sonography for airway assessment: an observational study. J Ultrasound Med. 2010;29(1):79-85. 7. Kundra P, Mishra SK, Ramesh A. Ultrasound of the airway. Indian J Anaesth. 2011;55(5):456-62. 8. Marchis IF, Negrut MF, Blebea CM, Crihan M, Alexa AL, Breazu CM. Trends in Preoperative Airway Assessment. Diagnostics (Basel). 2024;14(6). 9. Yao W, Wang B. Can tongue thickness measured by ultrasonography predict difficult tracheal intubation? Br J Anaesth. 2017;118(4):601-9. 10. Daggupati H, Maurya I, Singh RD, Ravishankar M. Development of a scoring system for predicting difficult intubation using ultrasonography. Indian J Anaesth. 2020;64(3):187-92. 11. Sotoodehnia M, Khodayar M, Jalali A, Momeni M, Safaie A, Abdollahi A. Prediction of difficult laryngoscopy / difficult intubation cases using upper airway ultrasound measurements in emergency department: a prospective observational study. BMC Emerg Med. 2023;23(1):78
Gunes A, Telli̇ S, Balci C. Preoperative Airway ultrasonography for predicting difficult intubation: comparative performance of skin-to-epiglottis distance and bedside tests - a prospective observational study. BMC Anesthesiol. 2026 Jun 11. doi: 10.1186/s12871-026-04011-7. Online ahead of print.
PubMed 42277691
Study at a glance
From the registry record, last updated by the sponsor on 5 Feb 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Investigation of Ultrasonographic Predictors of Difficult Intubation and Difficult Mask Ventilation in Adult Patients
- ClinicalTrials.gov ID
- NCT07383610
- Acronym / sponsor ID
- 2023/10-19
- Keywords
- Airway Ultrasonography, Ultrasound, Difficult Airway Prediction, Anesthesia
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 400 participants (actual)
- Lead sponsor
- Kutahya Health Sciences UniversityUniversity, hospital or other
- Study start
- 1 Oct 2023 (actual)
- Primary completion
- 1 Oct 2024 (actual)
- Study completion
- 1 Oct 2024 (actual)
- First posted
- 3 Feb 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.
Difficult airway management is a major cause of perioperative complications. Standard bedside airway assessment tests may have limited ability to predict difficult intubation and difficult mask ventilation. This prospective observational study aims to evaluate whether preoperative ultrasound measurements of airway structures (such as skin-to-epiglottis distance, tongue thickness, and pre-epiglottic space) can predict difficult intubation and difficult mask ventilation in adult patients undergoing surgery under general anesthesia.
Detailed description
This prospective observational cohort study was conducted to evaluate the predictive value of preoperative ultrasonographic airway measurements for difficult intubation and difficult mask ventilation in adult patients undergoing elective surgery under general anesthesia. A total of 400 patients aged 18-70 years with ASA physical status I-III were included. Before induction of anesthesia, standard clinical airway assessment tests were recorded, and ultrasound measurements were performed to assess airway-related anatomical structures. Ultrasonographic parameters included skin-to-epiglottis distance, skin-to-thyroid cartilage distance, thyroid cartilage-to-epiglottis distance, pre-epiglottic space depth, tongue thickness, and hyomental distance measurements.
Intraoperatively, mask ventilation and intubation conditions were documented. Difficult intubation was defined as requiring two or more intubation attempts. Difficult mask ventilation was defined as the need for two-handed mask ventilation or inability to ventilate adequately using a face mask. The primary objective was to determine the association between ultrasonographic measurements and difficult intubation
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Cohort 1: Adult patients undergoing surgery under general anesthesia | – | –Adult patients (18-70 years, ASA I-III) scheduled for elective surgery under general anesthesia requiring orotracheal intubation. Preoperative clinical airway assessment and ultrasonographic airway measurements were recorded, and intraoperative intubation and mask ventilation outcomes were evaluated |
Who may qualify
- Ages
- 18 to 70 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Adult patients aged 18-70 years (ASA I-III) scheduled for elective surgery under general anesthesia requiring orotracheal intubation
Key inclusion criteria (4 listed)
- Age 18-70 years
- ASA physical status I-III
- Elective surgery under general anesthesia requiring orotracheal intubation
- Written informed consent
Key exclusion criteria (11 listed)
- Refusal to participate
- Emergency surgery
- Pregnancy
- Known upper airway pathology or previous airway surgery
- Restricted mouth opening (<3 cm)
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
Number of Participants with Difficult Intubation
Time frame: During induction of anesthesia (intraoperative)
Difficult intubation was defined as requiring two or more intubation attempts (≥2 attempts) during induction of general anesthesia.
Number of Participants with Difficult Mask Ventilation
Time frame: During induction of anesthesia (intraoperative)
Difficult mask ventilation was defined as the need for two-handed mask ventilation or inability to ventilate adequately using a face mask
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 5 Feb 2026.
- Results publication1. Cook TM, MacDougall-Davis SR. Complications and failure of airway management. Br J Anaesth. 2012;109 Suppl 1(suppl 1):i68-i85. 2. Apfelbaum JL, Hagberg CA, Connis RT, Abdelmalak BB, Agarkar M, Dutton RP, et al. 2022 American Society of Anesthesiologists Practice Guidelines for Management of the Difficult Airway. Anesthesiology. 2022;136(1):31-81. 3. Roth D, Pace NL, Lee A, Hovhannisyan K, Warenits AM, Arrich J, et al. Airway physical examination tests for detection of difficult airway management in apparently normal adult patients. Cochrane Database Syst Rev. 2018;5(5):CD008874. 4. Shiga T, Wajima Z, Inoue T, Sakamoto A. Predicting difficult intubation in apparently normal patients: a meta-analysis of bedside screening test performance. Anesthesiology. 2005;103(2):429-37. 5. Detsky ME, Jivraj N, Adhikari NK, Friedrich JO, Pinto R, Simel DL, et al. Will This Patient Be Difficult to Intubate?: The Rational Clinical Examination Systematic Review. JAMA. 2019;321(5):493-503. 6. Singh M, Chin KJ, Chan VW, Wong DT, Prasad GA, Yu E. Use of sonography for airway assessment: an observational study. J Ultrasound Med. 2010;29(1):79-85. 7. Kundra P, Mishra SK, Ramesh A. Ultrasound of the airway. Indian J Anaesth. 2011;55(5):456-62. 8. Marchis IF, Negrut MF, Blebea CM, Crihan M, Alexa AL, Breazu CM. Trends in Preoperative Airway Assessment. Diagnostics (Basel). 2024;14(6). 9. Yao W, Wang B. Can tongue thickness measured by ultrasonography predict difficult tracheal intubation? Br J Anaesth. 2017;118(4):601-9. 10. Daggupati H, Maurya I, Singh RD, Ravishankar M. Development of a scoring system for predicting difficult intubation using ultrasonography. Indian J Anaesth. 2020;64(3):187-92. 11. Sotoodehnia M, Khodayar M, Jalali A, Momeni M, Safaie A, Abdollahi A. Prediction of difficult laryngoscopy / difficult intubation cases using upper airway ultrasound measurements in emergency department: a prospective observational study. BMC Emerg Med. 2023;23(1):78
- Derived from this study: PubMed 42277691Gunes A, Telli̇ S, Balci C. Preoperative Airway ultrasonography for predicting difficult intubation: comparative performance of skin-to-epiglottis distance and bedside tests - a prospective observational study. BMC Anesthesiol. 2026 Jun 11. doi: 10.1186/s12871-026-04011-7. Online ahead of print.
- Individual participant dataSharing planned: No. Individual participant data will not be shared due to institutional policies and to protect participant privacy and confidentiality.
Related trials for Difficult Intubation
Enrolling by invitation
Pediatric Intubation Simulations With Bougie
Difficult Airway Intubation
Not yet recruitingObservational study
Sniper Intubation for Training of Undergraduate Medical Student
Intubation;Difficult
RecruitingObservational study
Airway Ultrasound in Oncologic Maxillofacial Patients
Head and Neck Cancer
Not yet recruitingObservational study
Sniffing Position vs Left Head Rotation (LeHeR) Maneuver for Glottic View During Direct Laryngoscopy
Difficult Intubation, Laryngoscopy
Not yet recruitingObservational study
LeHeR Maneuver vs Sniffing Position During Video Laryngoscopy in Predicted Difficult Airway
Difficult Airway, Difficult Intubation
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.
Serkan Telli, MD principal investigator
Kutahya Health Sciences University
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 Difficult Intubation and Difficult Mask Ventilation, run by Kutahya Health Sciences 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 11 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 5 Feb 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?
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?
Number of Participants with Difficult Intubation (time frame: During induction of anesthesia (intraoperative)). 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?
On the ClinicalTrials.gov record for NCT07383610, which also lists 2 linked publications.
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 5 Feb 2026.