Difficult AirwayNCT07077317
Examining the Effects of Anthropometric Measurements on Difficult Airway Prediction
An observational study of Difficult Airway and Difficult Airway Intubation, run by Kutahya Health Sciences University at 1 site in Turkey (Türkiye).
Trial summary
Airway-related complications are among the leading causes of anesthesia-associated morbidity and mortality. Therefore, the ability to predict difficult mask ventilation, laryngoscopy, and intubation before induction is essential to ensure proper preparation in patients at risk and avoid unnecessary airway… Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Difficult Airway, Difficult Airway Intubation, Airway Management
- What is being tested?
- Airway Assessment Using Standard Clinical Tools
- How many people
- 1,044 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 13 Aug 2025to 11 Nov 2025
- How long will I take part?
- 1 Day
- 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 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Adult patients undergoing elective surgical procedures requiring endotracheal intubation under general anesthesia at a tertiary hospital.
Who may be able to join
- Age ≥ 18 years,
- ASA Physical Status I, II, III or IV,
- Undergoing elective surgery under general anesthesia with endotracheal intubation,
- Written informed consent provided
Who cannot join
- History of head and neck surgery or trauma causing anatomical deformity,
- Known congenital or acquired airway abnormality,
- Cervical spine surgery or instability,
- Age < 18 years
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Department of Anesthesiology, KUTAHYA CITY HOSPITAL
Kütahya, 43020
About this study
Official title: Examining the Effects of the Stop-Bang Scoring Model, Anthropometric Measurements, and Head Dimensions on Difficult Airway Prediction
Airway-related complications are among the leading causes of anesthesia-associated morbidity and mortality. Therefore, the ability to predict difficult mask ventilation, laryngoscopy, and intubation before induction is essential to ensure proper preparation in patients at risk and avoid unnecessary airway manipulations in low-risk individuals. While numerous studies have focused on predicting difficult intubation, most have limited sample sizes and do not consider postoperative critical respiratory events.
In this prospective observational clinical study, we aim to investigate the relationship between commonly used preoperative airway assessment tools-including anthropometric measurements, Mallampati score, and the STOP-Bang questionnaire for obstructive sleep apnea-and the incidence of difficult mask ventilation, difficult laryngoscopy (Cormack-Lehane grading), difficult intubation, and critical respiratory events in the postoperative period.
The study will include adult patients (≥18 years) classified as ASA I-IV undergoing surgery under general anesthesia with endotracheal intubation. Data will be collected preoperatively, intraoperatively, and in the post-anesthesia care unit (PACU) by experienced anesthesia personnel. Postoperative critical respiratory events are defined as unexpected hypoxemia, hypoventilation, reintubation, or interventions required for upper/lower airway obstruction.
Read the detailed description
Difficult airway management remains one of the most significant challenges in clinical anesthesia, often leading to severe complications such as hypoxemia, aspiration, and even cardiac arrest. Despite various clinical predictors, no single assessment method reliably identifies all patients at risk. This prospective, observational study aims to comprehensively evaluate the association between preoperative airway assessment parameters and both intraoperative airway difficulty and postoperative critical respiratory events.
The preoperative assessment will include demographic characteristics, comorbidities, ASA classification, Mallampati score, and detailed anthropometric airway measurements (neck circumference, thyromental distance, sternomental distance, interincisor gap, head dimensions, presence of beard/dentition, and neck mobility). Additionally, the STOP-Bang questionnaire will be administered to assess the risk of obstructive sleep apnea (OSA).
During induction and airway management, mask ventilation difficulty will be graded, Cormack-Lehane score during laryngoscopy will be recorded, and intubation will be evaluated in terms of the number of attempts and need for adjunctive devices (stylet, bougie, fiberoptic bronchoscope, videolaryngoscope, etc.).
In the postoperative phase, patients will be monitored for critical respiratory events including unexpected hypoxemia (SpO₂ <90%), hypoventilation (RR <8/min or PaCO₂ >50 mmHg), reintubation, and any interventions (e.g., airway support, bronchodilators, cold mist, etc.) required for upper or lower airway obstruction.
The outcomes of this study may help refine preoperative screening protocols and contribute to the development of risk-based airway management strategies aimed at improving patient safety.
- Being tested
- Airway Assessment Using Standard Clinical Tools
- Keywords
- mask ventilation, intubation, Cormack-Lehane, Airway Assessment
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Airway Assessment Using Standard Clinical ToolsOther
Preoperative airway evaluation using routine physical measurements (e.g., Mallampati score, neck circumference, STOP-Bang questionnaire), and intraoperative/postoperative observation of airway-related parameters.
What is being measured
The primary outcome is the main question the study is designed to answer.
Incidence of Difficult Mask Ventilation
Evaluation of mask ventilation using a standard difficulty grading scale.
- Mask Ventilation Successful
- Mask Ventilation Requires Oral Airway
- Mask Ventilation Requires Oral Airway And Assistant (Two Hands)
- Mask Ventilation Failure
Measured: Intraoperative (during anesthesia induction)
Incidence of Difficult Laryngoscopy
Cormack-Lehane grade III-IV views considered difficult laryngoscopy.
Measured: Intraoperative (during laryngoscopy)
Incidence of Difficult Intubation
Defined as more than two attempts, or the requirement of adjuncts such as bougie, videolaryngoscope, or fiberoptic bronchoscope.
Measured: Intraoperative (during intubation)
Occurrence of Postoperative Critical Respiratory Events
Events include unexpected hypoxemia (SpO₂ < 90%), hypoventilation (RR < 8/min or PaCO₂ > 50 mmHg), reintubation, and active interventions for airway obstruction.
Measured: Within the first 2 hours postoperatively (in PACU)
Secondary outcomes (3)
Correlation Between STOP-Bang Score and Difficult Airway Incidence
Evaluate predictive value of high STOP-Bang scores (≥3) for difficult mask ventilation, laryngoscopy, and intubation.
Measured: Preoperative through intraoperative period
Correlation Between Anthropometric Measurements and Critical Respiratory Events
Investigate associations between variables such as neck circumference, interincisor gap, or sternomental distance with postoperative respiratory complications.
Measured: Preoperative to postoperative period
Correlation Between Anthropometric Measurements and Difficult Airway Management
Investigate associations between variables such as neck circumference, interincisor gap, or sternomental distance, head dimensions, with difficult mask ventilation or difficult intubation.
Measured: Preoperative to intraoperative (induction period of anesthesia)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Jul 2025
- Study start13 Aug 2025
- Primary completion30 Oct 2025
- Study completion11 Nov 2025
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Difficult AirwayStudies 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
- 1,044 participants (actual)
- Target duration
- 1 Day
Sponsor and investigators
- Lead sponsor
- Kutahya Health Sciences University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Suleyman Camgoz, Kutahya Health Sciences University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07077317
- Sponsor's protocol ID
- E-41997688-050.99-177377
- Status last verified
- Nov 2025
- First submitted
- 11 Jul 2025
- Last updated
- 25 Nov 2025
- 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 25 Nov 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Examining the Effects of the Stop-Bang Scoring Model, Anthropometric Measurements, and Head Dimensions on Difficult Airway Prediction
- ClinicalTrials.gov ID
- NCT07077317
- Acronym / sponsor ID
- E-41997688-050.99-177377
- Keywords
- mask ventilation, intubation, Cormack-Lehane, Airway Assessment
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 1,044 participants (actual)
- Lead sponsor
- Kutahya Health Sciences UniversityUniversity, hospital or other
- Study start
- 13 Aug 2025 (actual)
- Primary completion
- 30 Oct 2025 (actual)
- Study completion
- 11 Nov 2025 (actual)
- First posted
- 22 Jul 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.
Airway-related complications are among the leading causes of anesthesia-associated morbidity and mortality. Therefore, the ability to predict difficult mask ventilation, laryngoscopy, and intubation before induction is essential to ensure proper preparation in patients at risk and avoid unnecessary airway manipulations in low-risk individuals. While numerous studies have focused on predicting difficult intubation, most have limited sample sizes and do not consider postoperative critical respiratory events.
In this prospective observational clinical study, we aim to investigate the relationship between commonly used preoperative airway assessment tools-including anthropometric measurements, Mallampati score, and the STOP-Bang questionnaire for obstructive sleep apnea-and the incidence of difficult mask ventilation, difficult laryngoscopy (Cormack-Lehane grading), difficult intubation, and critical respiratory events in the postoperative period.
The study will include adult patients (≥18 years) classified as ASA I-IV undergoing surgery under general anesthesia with endotracheal intubation. Data will be collected preoperatively, intraoperatively, and in the post-anesthesia care unit (PACU) by experienced anesthesia personnel. Postoperative critical respiratory events are defined as unexpected hypoxemia, hypoventilation, reintubation, or interventions required for upper/lower airway obstruction.
Detailed description
Difficult airway management remains one of the most significant challenges in clinical anesthesia, often leading to severe complications such as hypoxemia, aspiration, and even cardiac arrest. Despite various clinical predictors, no single assessment method reliably identifies all patients at risk. This prospective, observational study aims to comprehensively evaluate the association between preoperative airway assessment parameters and both intraoperative airway difficulty and postoperative critical respiratory events.
The preoperative assessment will include demographic characteristics, comorbidities, ASA classification, Mallampati score, and detailed anthropometric airway measurements (neck circumference, thyromental distance, sternomental distance, interincisor gap, head dimensions, presence of beard/dentition, and neck mobility). Additionally, the STOP-Bang questionnaire will be administered to assess the risk of obstructive sleep apnea (OSA).
During induction and airway management, mask ventilation difficulty will be graded, Cormack-Lehane score during laryngoscopy will be recorded, and intubation will be evaluated in terms of the number of attempts and need for adjunctive devices (stylet, bougie, fiberoptic bronchoscope, videolaryngoscope, etc.).
In the postoperative phase, patients will be monitored for critical respiratory events including unexpected hypoxemia (SpO₂ <90%), hypoventilation (RR <8/min or PaCO₂ >50 mmHg), reintubation, and any interventions (e.g., airway support, bronchodilators, cold mist, etc.) required for upper or lower airway obstruction.
The outcomes of this study may help refine preoperative screening protocols and contribute to the development of risk-based airway management strategies aimed at improving patient safety.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Target follow-up
- 1 Day
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Adult patients undergoing elective surgical procedures requiring endotracheal intubation under general anesthesia at a tertiary hospital.
Key inclusion criteria (4 listed)
- Age ≥ 18 years,
- ASA Physical Status I, II, III or IV,
- Undergoing elective surgery under general anesthesia with endotracheal intubation,
- Written informed consent provided
Key exclusion criteria (4 listed)
- History of head and neck surgery or trauma causing anatomical deformity,
- Known congenital or acquired airway abnormality,
- Cervical spine surgery or instability,
- Age < 18 years
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 |
|---|---|---|
| Airway Assessment Using Standard Clinical ToolsPreoperative airway evaluation using routine physical measurements (e.g., Mallampati score, neck circumference, STOP-Bang questionnaire), and intraoperative/postoperative observation of airway-related parameters. | Other | – |
Primary outcome
Incidence of Difficult Mask Ventilation
Time frame: Intraoperative (during anesthesia induction)
Evaluation of mask ventilation using a standard difficulty grading scale. 1. Mask Ventilation Successful 2. Mask Ventilation Requires Oral Airway 3. Mask Ventilation Requires Oral Airway And Assistant (Two Hands) 4. Mask Ventilation Failure
Incidence of Difficult Laryngoscopy
Time frame: Intraoperative (during laryngoscopy)
Cormack-Lehane grade III-IV views considered difficult laryngoscopy.
Incidence of Difficult Intubation
Time frame: Intraoperative (during intubation)
Defined as more than two attempts, or the requirement of adjuncts such as bougie, videolaryngoscope, or fiberoptic bronchoscope.
Occurrence of Postoperative Critical Respiratory Events
Time frame: Within the first 2 hours postoperatively (in PACU)
Events include unexpected hypoxemia (SpO₂ < 90%), hypoventilation (RR < 8/min or PaCO₂ > 50 mmHg), reintubation, and active interventions for airway obstruction.
3 secondary outcomes
Correlation Between STOP-Bang Score and Difficult Airway Incidence
Time frame: Preoperative through intraoperative period
Correlation Between Anthropometric Measurements and Critical Respiratory Events
Time frame: Preoperative to postoperative period
Correlation Between Anthropometric Measurements and Difficult Airway Management
Time frame: Preoperative to intraoperative (induction period of anesthesia)
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 25 Nov 2025.
- 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.
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 Difficult Airway and Difficult Airway Intubation, 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 4 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 25 Nov 2025. 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?
Incidence of Difficult Mask Ventilation (time frame: Intraoperative (during anesthesia induction)). The study lists 4 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 25 Nov 2025; AzTrials last refreshed its copy on 7 Nov 2026.