Difficult Airway IntubationintubationNCT07461792
New Method for Evaluation of Difficult Intubation in Adults
An observational study of Difficult Airway Intubation, run by Sohag University at 1 site in Egypt.
Trial summary
There are multiple scores used for airway assesment ,the commonest one is LEMON score. LEMON is an airway assessment score that measures factors associated with difficult intubation such as obesity, head and neck movement, jaw movement , receding mandible, long upper incisors, Mallampatti scores, maxillary incisor… Read more about this study
- Who is it for?
- Ages 15 to 60 yearsHealthy volunteers can take part
- Conditions the study is for
- Difficult Airway Intubation
- What is being tested?
- evaluation of difficult intubation
- How many people
- 350 participants
- Where
- 1 siteEgypt
- Study dates
- 5 Jan 2026to 15 Jul 2026
- 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 15 to 60 years
- All sexes
- Healthy volunteers accepted
- Child, Adult
Study population: The sample size calculation was performed using G. power 3.1.9.2 (Universitat Kiel, Germany) and total sample size will be 350. It was calculated according to a previous study (Pal et al., 2025, Rista et al., 2025) based the sensitivity of Height/Thyromental Distance Ratio and L.E.M.O.N score as to best of our knowledge our study will be the first to assess Height/Thyromental Distance Ratio Combined with Obstruction and Neck Mobility (HON Model) to predict difficult intubation (Power : 0.8, α error: 0.05).
Who may be able to join
- Adult patients from 15- 60 yrs old
- Patients who require endotracheal intubation for surgery under general anesthesia.
- Patients with ASA I - II
- Patients who provide informed consent
Who cannot join
- Patients with history of previous difficult intubation.
- Patients with inability to sit/stand, heamodinamiclly unstable and need for rapid sequence induction .
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Evaluation of Height/Thyromental Distance Ratio Combined With Obstruction and Neck Mobility for Predicting Difficult Endotracheal Intubation in Adults : A Prospective Observational Study
There are multiple scores used for airway assesment ,the commonest one is LEMON score. LEMON is an airway assessment score that measures factors associated with difficult intubation such as obesity, head and neck movement, jaw movement , receding mandible, long upper incisors, Mallampatti scores, maxillary incisor characteristics, decreased mouth opening ,shorten thyromental distance and short neck.
The Height-to-Thyromental Distance ratio (H/TMD) has emerged as a simple, objective, and reproducible anatomical predictor of difficult laryngoscopy, as it normalizes mandibular space to patient height. However, airway difficulty is not purely anatomical; functional factors such as airway obstruction and cervical spine mobility significantly affect intubation success.
Therefore, combining H/TMD with two highly predictive functional elements from the LEMON score - Obstruction (O) and Neck Mobility (N) - may provide a more accurate, simplified, and clinically applicable model for predicting difficult airway. This combination is referred to as the HON Model (Height/TMD + Obstruction + Neck mobility).
- Conditions
- Difficult Airway Intubation
- Being tested
- evaluation of difficult intubation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
evaluation of difficult intubationOther
The Height-to-Thyromental Distance ratio (H/TMD) has emerged as a simple, objective, and reproducible anatomical predictor of difficult laryngoscopy, as it normalizes mandibular space to patient height. However, airway difficulty is not purely anatomical; functional factors such as airway obstruction and cervical spine mobility significantly affect intubation success.
Therefore, combining H/TMD with two highly predictive functional elements from the LEMON score - Obstruction (O) and Neck Mobility (N) - may provide a more accurate, simplified, and clinically applicable model for predicting difficult airway. This combination is referred to as the HON Model (Height/TMD + Obstruction + Neck mobility).
| Study group | Role | What they receive |
|---|---|---|
| - Adult patients from 15- 60 yrs old - Patients who require endotracheal intubation for su | Not described Receives: Other: evaluation of difficult intubation |
What is being measured
The primary outcome is the main question the study is designed to answer.
The primary outcome evaluate using Ratio of Patient's Height to Thyromental Distance Combined with Obstruction and Neck Mobility (HON Model) as a new practical scoring system in predicting Difficult Laryngoscopy .
Measured: 30 minutes
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted10 Mar 2026
- Study start5 Jan 2026
- Primary completion15 Jun 2026 (estimated)
- Study completion15 Jul 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Difficult Airway IntubationStudies of the same condition, open and under way.
- More trials run by Sohag 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
- 350 participants (estimated)
- Target duration
- 1 Day
Sponsor and investigators
- Lead sponsor
- Sohag University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Mohamed Foaad, Sohag University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07461792
- Sponsor's protocol ID
- Soh-Med-26-2-15MS
- Acronym
- intubation
- Status last verified
- Apr 2026
- First submitted
- 5 Mar 2026
- Last updated
- 17 Apr 2026
- Results posted
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 17 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Evaluation of Height/Thyromental Distance Ratio Combined With Obstruction and Neck Mobility for Predicting Difficult Endotracheal Intubation in Adults : A Prospective Observational Study
- ClinicalTrials.gov ID
- NCT07461792
- Acronym / sponsor ID
- intubation / Soh-Med-26-2-15MS
- Conditions
- Difficult Airway Intubation
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 350 participants (estimated)
- Lead sponsor
- Sohag UniversityUniversity, hospital or other
- Study start
- 5 Jan 2026 (actual)
- Primary completion
- 15 Jun 2026 (estimated)
- Study completion
- 15 Jul 2026 (estimated)
- First posted
- 10 Mar 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.
There are multiple scores used for airway assesment ,the commonest one is LEMON score. LEMON is an airway assessment score that measures factors associated with difficult intubation such as obesity, head and neck movement, jaw movement , receding mandible, long upper incisors, Mallampatti scores, maxillary incisor characteristics, decreased mouth opening ,shorten thyromental distance and short neck.
The Height-to-Thyromental Distance ratio (H/TMD) has emerged as a simple, objective, and reproducible anatomical predictor of difficult laryngoscopy, as it normalizes mandibular space to patient height. However, airway difficulty is not purely anatomical; functional factors such as airway obstruction and cervical spine mobility significantly affect intubation success.
Therefore, combining H/TMD with two highly predictive functional elements from the LEMON score - Obstruction (O) and Neck Mobility (N) - may provide a more accurate, simplified, and clinically applicable model for predicting difficult airway. This combination is referred to as the HON Model (Height/TMD + Obstruction + Neck mobility).
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Target follow-up
- 1 Day
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| - Adult patients from 15- 60 yrs old - Patients who require endotracheal intubation for su | – | Other: evaluation of difficult intubation |
Who may qualify
- Ages
- 15 to 60 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult
- Study population
- The sample size calculation was performed using G. power 3.1.9.2 (Universitat Kiel, Germany) and total sample size will be 350. It was calculated according to a previous study (Pal et al., 2025, Rista et al., 2025) based the sensitivity of Height/Thyromental Distance Ratio and L.E.M.O.N score as to best of our knowledge our study will be the first to assess Height/Thyromental Distance Ratio Combined with Obstruction and Neck Mobility (HON Model) to predict difficult intubation (Power : 0.8, α error: 0.05).
Key inclusion criteria (4 listed)
- Adult patients from 15- 60 yrs old
- Patients who require endotracheal intubation for surgery under general anesthesia.
- Patients with ASA I - II
- Patients who provide informed consent
Key exclusion criteria (2 listed)
- Patients with history of previous difficult intubation.
- Patients with inability to sit/stand, heamodinamiclly unstable and need for rapid sequence induction .
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 |
|---|---|---|
| evaluation of difficult intubationThe Height-to-Thyromental Distance ratio (H/TMD) has emerged as a simple, objective, and reproducible anatomical predictor of difficult laryngoscopy, as it normalizes mandibular space to patient height. However, airway difficulty is not purely anatomical; functional factors such as airway obstruction and cervical spine mobility significantly affect intubation success. Therefore, combining H/TMD with two highly predictive functional elements from the LEMON score - Obstruction (O) and Neck Mobility (N) - may provide a more accurate, simplified, and clinically applicable model for predicting difficult airway. This combination is referred to as the HON Model (Height/TMD + Obstruction + Neck mobility). | Other | - Adult patients from 15- 60 yrs old - Patients who require endotracheal intubation for su |
Primary outcome
The primary outcome evaluate using Ratio of Patient's Height to Thyromental Distance Combined with Obstruction and Neck Mobility (HON Model) as a new practical scoring system in predicting Difficult Laryngoscopy .
Time frame: 30 minutes
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 17 Apr 2026.
- Individual participant dataSharing planned: Undecided
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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 Intubation, run by Sohag University at 1 site in Egypt.
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 2 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: under way, not looking for participants, as of the sponsor's last update on 17 Apr 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 Egypt. 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 primary outcome evaluate using Ratio of Patient's Height to Thyromental Distance Combined with Obstruction and Neck Mobility (HON Model) as a new practical scoring system in predicting Difficult Laryngoscopy . (time frame: 30 minutes). 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 17 Apr 2026.