Intubation, IntratrachealZVL-DTNCT07873138
A Novel Score for Procedural Difficulty During Videolaryngoscopic Intubation
An observational study of Intubation, Intratracheal and Airway Management, run by Nagihan Emiroglu at 1 site in Turkey (Türkiye).
Trial summary
Videolaryngoscopy generally improves the glottic view compared with direct laryngoscopy, yet a good view does not always translate into easy delivery of the tracheal tube. Existing classifications describe either the laryngeal view (Cormack-Lehane grade, percentage of glottic opening) or the overall difficulty of… Read more about this study
- Who is it for?
- Ages 18 years and olderHealthy volunteers can take part
- Conditions the study is for
- Intubation, Intratracheal, Airway Management, Videolaryngoscopy
- What is being tested?
- Videolaryngoscopic tracheal intubation
- How many people
- 250 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 15 Oct 2026to 28 Feb 2027
- How long will I take part?
- 1 Day
- 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
- Healthy volunteers accepted
- Adult, Older adult
Study population: Adult patients scheduled for elective surgery under general anaesthesia requiring tracheal intubation at a single tertiary centre. All patients are intubated with a Macintosh-blade videolaryngoscope by anaesthesiologists as part of routine clinical care. Consecutive eligible patients are enrolled during the study period.
Who may be able to join
- Age 18 years or older
- Elective surgery under general anaesthesia requiring tracheal intubation
- Tracheal intubation planned with a Macintosh-blade videolaryngoscope
Who cannot join
- Age under 18 years
- Planned awake intubation or a planned alternative primary airway technique (flexible bronchoscopic intubation, supraglottic airway as the definitive airway)
- Tracheal intubation performed outside the operating theatre
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
Sincan Research and Training Hospital
Ankara, 06932
Gamze Kübra Zelyurt, +90 5544879592, gamzekubra@windowslive.com
Nagihan Emiroğlu
About this study
Official title: Development and Validation of a Component-Based Score for Characterizing Procedural Difficulty During Videolaryngoscopic Tracheal Intubation: An Observational Study
Videolaryngoscopy generally improves the glottic view compared with direct laryngoscopy, yet a good view does not always translate into easy delivery of the tracheal tube. Existing classifications describe either the laryngeal view (Cormack-Lehane grade, percentage of glottic opening) or the overall difficulty of intubation (Intubation Difficulty Scale), but none characterizes which specific mechanism produces difficulty during videolaryngoscopic intubation.
This observational study evaluates a component-based score developed to describe procedural difficulty encountered during videolaryngoscopic tracheal intubation.
Read more
The score comprises four components, each graded 0 to 2 (total range 0 to 8):
view-tube concordance, restricted epiglottic movement, need for additional laryngoscopic manoeuvres, and need for tube-shaping adjustment.
Adult patients undergoing elective surgery under general anaesthesia with tracheal intubation performed using a Macintosh-blade videolaryngoscope were assessed. The primary objective is to examine the association between the total score and procedural outcomes: intubation time, number of attempts, and first-attempt success. Secondary objectives include the relationship of the score with the Intubation Difficulty Scale, the Video Classification of Intubation, percentage of glottic opening, preoperative airway assessment parameters and operator experience.
Read the detailed description
Videolaryngoscopy improves the glottic view compared with direct laryngoscopy, but an adequate view does not guarantee easy delivery of the tracheal tube into the trachea. Existing classifications address either the laryngeal view (Cormack-Lehane grade, percentage of glottic opening) or the overall difficulty of the intubation episode (Intubation Difficulty Scale). The Video Classification of Intubation records blade type, glottic opening and the ease of tube passage as a descriptive label. None of these tools identifies which specific mechanism produced the difficulty encountered during a videolaryngoscopic intubation.
SCORE UNDER EVALUATION
The score comprises four components, each graded 0, 1 or 2, giving a total range of 0 to 8:
- View-tube concordance: whether the tracheal tube can be advanced towards the glottic opening under the obtained view without additional manipulation.
- Restricted epiglottic movement: whether epiglottic behaviour interferes with visualisation of the glottic opening.
- Need for additional laryngoscopic manoeuvres: whether external laryngeal manipulation, blade repositioning or blade change was required to obtain the view.
- Need for tube-shaping adjustment: whether the stylet had to be reshaped or an alternative device such as a bougie was required to direct the tube.
The components were derived from concepts described in the Video Classification of Intubation tube-delivery category and the videolaryngoscopic intubation and difficult airway classification, and were operationalised on a 0 to 2 ordinal scale.
OBJECTIVES
The primary objective is to examine whether the total score is associated with procedural outcomes of the intubation: intubation time, number of attempts and first-attempt success.
Secondary objectives are to examine the relationship of the total score with the Intubation Difficulty Scale, with the Video Classification of Intubation tube delivery category and with the percentage of glottic opening; to examine the association of each individual component with the procedural outcomes; to examine the association of preoperative airway assessment parameters (Mallampati classification, mouth opening, thyromental distance, neck extension, dental prosthesis, upper lip bite test, history of difficult intubation, body mass index) with the total score; and to examine whether operator experience is associated with the score and with the procedural outcomes.
The study does not aim to define a threshold for difficult videolaryngoscopic intubation and does not classify intubations as easy, moderate or difficult. Adult patients undergoing elective surgery under general anaesthesia requiring tracheal intubation will be assessed. All intubations will be performed with a Macintosh-blade videolaryngoscope. For each intubation the four score components, the Intubation Difficulty Scale, the Video Classification of Intubation, the percentage of glottic opening, the Cormack-Lehane grade, preoperative airway assessment parameters, operator experience, intubation time, number of attempts, first-attempt success, need for additional manoeuvres and oxygen desaturation below 90 percent will be recorded.
Continuous variables will be summarised as median with interquartile range. Internal consistency of the score will be assessed with Cronbach's alpha and corrected item-total correlations, and its dimensionality with principal component analysis. Associations will be examined with Spearman rank correlation, Mann-Whitney U and Kruskal-Wallis tests, and with regression models appropriate to the distribution of each outcome.
- Being tested
- Videolaryngoscopic tracheal intubation
- Keywords
- tracheal intubation, difficult videolaryngoscopy, airway assessment
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Videolaryngoscopic tracheal intubationOther
Tracheal intubation performed under videolaryngoscopic guidance with a Macintosh-blade videolaryngoscope as part of routine anaesthetic care. The procedure is observed and scored; it is not assigned by the study protocol.
| Study group | Role | What they receive |
|---|---|---|
| Videolaryngoscopic tracheal intubation | Adult patients undergoing elective surgery under general anaesthesia who require tracheal intubation performed with a Macintosh-blade videolaryngoscope. Procedural difficulty is scored with the four-component score at the time of intubation, together with the Intubation Difficulty Scale, the Video Classification of Intubation, percentage of glottic opening and Cormack-Lehane grade. No study-specific intervention is assigned; airway management follows routine clinical practice. Receives: Other: Videolaryngoscopic tracheal intubation |
What is being measured
The primary outcome is the main question the study is designed to answer.
Association between the total score and intubation time
Intubation time is defined as the interval in seconds from insertion of the videolaryngoscope blade past the lips until confirmation of tracheal tube placement by capnography. Its association with the total four-component score (range 0 to 8) is assessed using Spearman rank correlation.
Measured: During the tracheal intubation procedure
Association between the total score and the number of intubation attempts
The number of intubation attempts is recorded for each patient. An attempt is defined as an effort to advance the tracheal tube towards the glottic opening; repositioning of the blade without advancing the tube is not counted as a separate attempt. The association with the total four-component score (range 0 to 8) is assessed using Spearman rank correlation and ordinal regression.
Measured: During the tracheal intubation procedure
Association between the total score and first-attempt intubation success
First-attempt success is defined as correct placement of the tracheal tube within a single intubation attempt. Its association with the total four-component score (range 0 to 8) is assessed using logistic regression with the score entered as a continuous variable.
Measured: During the tracheal intubation procedure
Secondary outcomes (3)
Association between the total score and the Intubation Difficulty Scale
The Intubation Difficulty Scale is calculated from its seven components for each intubation. Its association with the total four-component score (range 0 to 8) is assessed using Spearman rank correlation. Partial conceptual overlap between the two instruments is acknowledged and reported.
Measured: During the tracheal intubation procedure
Association between the total score and the Video Classification of Intubation tube delivery category
The Video Classification of Intubation records blade type, percentage of glottic opening and the ease of tube delivery as easy, difficult or failed. The distribution of the total four-component score across the easy and difficult categories is compared using the Mann-Whitney U test.
Measured: During the tracheal intubation procedure
Association between preoperative airway assessment parameters and the total score
Preoperative airway assessment parameters (Mallampati classification, mouth opening, thyromental distance, neck extension, dental prosthesis, upper lip bite test, history of difficult intubation and body mass index) are examined for their association with the total four-component score using Mann-Whitney U tests and Spearman rank correlation.
Measured: Preoperative airway assessment and the tracheal intubation procedure
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted14 Oct 2026
- Study start15 Oct 2026 (estimated)
- Primary completion31 Dec 2026 (estimated)
- Study completion28 Feb 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Intubation, IntratrachealStudies 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
- 250 participants (estimated)
- Target duration
- 1 Day
Sponsor and investigators
- Lead sponsor
- Nagihan Emiroglu
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor-investigator, Nagihan Emiroglu, Sincan Training and Research Hospital
- Investigators
- Gamze Kübra Zelyurt, Study director, Sincan Training and Research Hospital
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07873138
- Sponsor's protocol ID
- ZVL-DT-2026-01
- Acronym
- ZVL-DT
- Status last verified
- Oct 2026
- First submitted
- 7 Oct 2026
- Last updated
- 19 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 underlying the published results, including the four score components, comparator scores and procedural outcome variables, will be made available to qualified researchers upon reasonable request.
Study at a glance
From the registry record, last updated by the sponsor on 19 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Development and Validation of a Component-Based Score for Characterizing Procedural Difficulty During Videolaryngoscopic Tracheal Intubation: An Observational Study
- ClinicalTrials.gov ID
- NCT07873138
- Acronym / sponsor ID
- ZVL-DT / ZVL-DT-2026-01
- Keywords
- tracheal intubation, difficult videolaryngoscopy, airway assessment
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 250 participants (estimated)
- Lead sponsor
- Nagihan EmirogluUniversity, hospital or other
- Study start
- 15 Oct 2026 (estimated)
- Primary completion
- 31 Dec 2026 (estimated)
- Study completion
- 28 Feb 2027 (estimated)
- First posted
- 14 Oct 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.
Videolaryngoscopy generally improves the glottic view compared with direct laryngoscopy, yet a good view does not always translate into easy delivery of the tracheal tube. Existing classifications describe either the laryngeal view (Cormack-Lehane grade, percentage of glottic opening) or the overall difficulty of intubation (Intubation Difficulty Scale), but none characterizes which specific mechanism produces difficulty during videolaryngoscopic intubation.
This observational study evaluates a component-based score developed to describe procedural difficulty encountered during videolaryngoscopic tracheal intubation.
The score comprises four components, each graded 0 to 2 (total range 0 to 8):
view-tube concordance, restricted epiglottic movement, need for additional laryngoscopic manoeuvres, and need for tube-shaping adjustment.
Adult patients undergoing elective surgery under general anaesthesia with tracheal intubation performed using a Macintosh-blade videolaryngoscope were assessed. The primary objective is to examine the association between the total score and procedural outcomes: intubation time, number of attempts, and first-attempt success. Secondary objectives include the relationship of the score with the Intubation Difficulty Scale, the Video Classification of Intubation, percentage of glottic opening, preoperative airway assessment parameters and operator experience.
Detailed description
Videolaryngoscopy improves the glottic view compared with direct laryngoscopy, but an adequate view does not guarantee easy delivery of the tracheal tube into the trachea. Existing classifications address either the laryngeal view (Cormack-Lehane grade, percentage of glottic opening) or the overall difficulty of the intubation episode (Intubation Difficulty Scale). The Video Classification of Intubation records blade type, glottic opening and the ease of tube passage as a descriptive label. None of these tools identifies which specific mechanism produced the difficulty encountered during a videolaryngoscopic intubation.
SCORE UNDER EVALUATION
The score comprises four components, each graded 0, 1 or 2, giving a total range of 0 to 8:
- View-tube concordance: whether the tracheal tube can be advanced towards the glottic opening under the obtained view without additional manipulation.
- Restricted epiglottic movement: whether epiglottic behaviour interferes with visualisation of the glottic opening.
- Need for additional laryngoscopic manoeuvres: whether external laryngeal manipulation, blade repositioning or blade change was required to obtain the view.
- Need for tube-shaping adjustment: whether the stylet had to be reshaped or an alternative device such as a bougie was required to direct the tube.
The components were derived from concepts described in the Video Classification of Intubation tube-delivery category and the videolaryngoscopic intubation and difficult airway classification, and were operationalised on a 0 to 2 ordinal scale.
OBJECTIVES
The primary objective is to examine whether the total score is associated with procedural outcomes of the intubation: intubation time, number of attempts and first-attempt success.
Secondary objectives are to examine the relationship of the total score with the Intubation Difficulty Scale, with the Video Classification of Intubation tube delivery category and with the percentage of glottic opening; to examine the association of each individual component with the procedural outcomes; to examine the association of preoperative airway assessment parameters (Mallampati classification, mouth opening, thyromental distance, neck extension, dental prosthesis, upper lip bite test, history of difficult intubation, body mass index) with the total score; and to examine whether operator experience is associated with the score and with the procedural outcomes.
The study does not aim to define a threshold for difficult videolaryngoscopic intubation and does not classify intubations as easy, moderate or difficult. Adult patients undergoing elective surgery under general anaesthesia requiring tracheal intubation will be assessed. All intubations will be performed with a Macintosh-blade videolaryngoscope. For each intubation the four score components, the Intubation Difficulty Scale, the Video Classification of Intubation, the percentage of glottic opening, the Cormack-Lehane grade, preoperative airway assessment parameters, operator experience, intubation time, number of attempts, first-attempt success, need for additional manoeuvres and oxygen desaturation below 90 percent will be recorded.
Continuous variables will be summarised as median with interquartile range. Internal consistency of the score will be assessed with Cronbach's alpha and corrected item-total correlations, and its dimensionality with principal component analysis. Associations will be examined with Spearman rank correlation, Mann-Whitney U and Kruskal-Wallis tests, and with regression models appropriate to the distribution of each outcome.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Target follow-up
- 1 Day
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Videolaryngoscopic tracheal intubation | – | Other: Videolaryngoscopic tracheal intubationAdult patients undergoing elective surgery under general anaesthesia who require tracheal intubation performed with a Macintosh-blade videolaryngoscope. Procedural difficulty is scored with the four-component score at the time of intubation, together with the Intubation Difficulty Scale, the Video Classification of Intubation, percentage of glottic opening and Cormack-Lehane grade. No study-specific intervention is assigned; airway management follows routine clinical practice. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
- Study population
- Adult patients scheduled for elective surgery under general anaesthesia requiring tracheal intubation at a single tertiary centre. All patients are intubated with a Macintosh-blade videolaryngoscope by anaesthesiologists as part of routine clinical care. Consecutive eligible patients are enrolled during the study period.
Key inclusion criteria (3 listed)
- Age 18 years or older
- Elective surgery under general anaesthesia requiring tracheal intubation
- Tracheal intubation planned with a Macintosh-blade videolaryngoscope
Key exclusion criteria (3 listed)
- Age under 18 years
- Planned awake intubation or a planned alternative primary airway technique (flexible bronchoscopic intubation, supraglottic airway as the definitive airway)
- Tracheal intubation performed outside the operating theatre
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 |
|---|---|---|
| Videolaryngoscopic tracheal intubationTracheal intubation performed under videolaryngoscopic guidance with a Macintosh-blade videolaryngoscope as part of routine anaesthetic care. The procedure is observed and scored; it is not assigned by the study protocol. | Other | Videolaryngoscopic tracheal intubation |
Primary outcome
Association between the total score and intubation time
Time frame: During the tracheal intubation procedure
Intubation time is defined as the interval in seconds from insertion of the videolaryngoscope blade past the lips until confirmation of tracheal tube placement by capnography. Its association with the total four-component score (range 0 to 8) is assessed using Spearman rank correlation.
Association between the total score and the number of intubation attempts
Time frame: During the tracheal intubation procedure
The number of intubation attempts is recorded for each patient. An attempt is defined as an effort to advance the tracheal tube towards the glottic opening; repositioning of the blade without advancing the tube is not counted as a separate attempt. The association with the total four-component score (range 0 to 8) is assessed using Spearman rank correlation and ordinal regression.
Association between the total score and first-attempt intubation success
Time frame: During the tracheal intubation procedure
First-attempt success is defined as correct placement of the tracheal tube within a single intubation attempt. Its association with the total four-component score (range 0 to 8) is assessed using logistic regression with the score entered as a continuous variable.
3 secondary outcomes
Association between the total score and the Intubation Difficulty Scale
Time frame: During the tracheal intubation procedure
Association between the total score and the Video Classification of Intubation tube delivery category
Time frame: During the tracheal intubation procedure
Association between preoperative airway assessment parameters and the total score
Time frame: Preoperative airway assessment and the tracheal intubation procedure
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 19 Oct 2026.
- Individual participant dataSharing planned: Yes. De-identified individual participant data underlying the published results, including the four score components, comparator scores and procedural outcome variables, will be made available to qualified 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.
Gamze Kübra Zelyurt study director
Sincan Training 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 Intubation, Intratracheal and Airway Management, run by Nagihan Emiroglu 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 3 inclusion and 3 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 19 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?
Contact Gamze Kübra Zelyurt (+905544879592, gamzekubra@windowslive.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Association between the total score and intubation time (time frame: During the tracheal intubation procedure). The study lists 3 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 19 Oct 2026.