Difficult AirwayNCT07846748
Correlation Between Bedside Anatomical Indicators and Lifting Force and Glottic Exposure Under Different Video Laryngoscopy Techniques
An observational study of Difficult Airway and Intubation, Intratracheal, run by Second Hospital of Shanxi Medical University.
Trial summary
This single-center prospective observational study plans to enroll 196 patients undergoing elective general anesthesia. The study aims to investigate the correlation between preoperative bedside anatomical indicators (including modified Mallampati classification, upper lip bite test, mouth opening, head circumference… Read more about this study
- Who is it for?
- Ages 18 to 75 years
- Conditions the study is for
- Difficult Airway, Intubation, Intratracheal
- What is being tested?
- Direct Epiglottis Elevation (Subepiglottic Method)
- Type of treatment
- Surgery or procedure
- How many people
- 200 participants
- Where
- No sites listed yet
- Study dates
- 1 Oct 2026to 1 Jun 2027
- 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 75 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: Adult patients aged 18 to 75 years with ASA physical status I to III who are scheduled for elective surgery under general anesthesia requiring orotracheal intubation under video laryngoscopy guidance. Patients with known difficult airway, facial or neck abnormalities affecting landmark palpation, limited mouth opening (< 2.0 cm), or edentulism are excluded.
Who may be able to join
- - Age 18 to 75 years
- ASA physical status I to III
- Scheduled for orotracheal intubation under video laryngoscopy guidance
- Written informed consent obtained
Who cannot join
- Known history of difficult airway or anticipated need for awake intubation
- Facial or neck trauma, burns, or surgical history affecting palpation of anatomical landmarks
- Temporomandibular joint ankylosis or mouth opening < 2.0 cm
- Edentulous patients
Trial locations and contacts
No sites are listed yet. Contact the study team or a site near you to ask about taking part.
About this study
This single-center prospective observational study plans to enroll 196 patients undergoing elective general anesthesia. The study aims to investigate the correlation between preoperative bedside anatomical indicators (including modified Mallampati classification, upper lip bite test, mouth opening, head circumference, and thyromental distance) and the peak lifting force applied during video laryngoscopy, as well as the degree of glottic exposure (POGO score). The study will also evaluate the potential benefit of the direct epiglottis elevation technique in specific anatomical subgroups. After anesthesia induction, the same anesthesiologist will perform video laryngoscopy using two distinct techniques in a fixed sequence: the indirect (vallecula) method and the direct (subepiglottic) method. Peak lifting force will be quantitatively measured in real-time using a resistive thin-film pressure sensor attached to the laryngoscope blade. The primary outcomes are the POGO scores and peak lifting forces under both techniques. The secondary outcome includes the change in POGO score (ΔPOGO) between techniques. The study will provide quantitative evidence regarding the "anatomy-force-view" relationship and aid in individualized clinical decision-making for video laryngoscopy intubation.
Read the detailed description
This study is a single-center, prospective, observational study. A total of 196 adult patients scheduled for elective surgery under general anesthesia requiring orotracheal intubation will be enrolled. Preoperative bedside anatomical assessment will be performed by a standardized, blinded evaluator. The assessed indicators include mouth opening, thyromental distance, modified Mallampati classification, upper lip bite test, head circumference, and neck circumference. After standard anesthesia induction, video laryngoscopy will be performed by an experienced anesthesiologist. Two techniques will be evaluated in a fixed sequence: (1) Indirect epiglottis elevation (vallecula method): the blade tip is placed in the vallecula to indirectly elevate the epiglottis by lifting the tongue base. (2) Direct epiglottis elevation (subepiglottic method): the blade tip is advanced past the vallecula and placed directly under the laryngeal surface of the epiglottis to actively lift it. A resistive thin-film pressure sensor attached to the video laryngoscope blade will continuously record real-time force data, and the peak lifting force will be extracted for analysis. Glottic exposure will be evaluated using the Percentage of Glottic Opening (POGO) score. Between the two assessments, mask ventilation will be performed for at least 2 minutes to maintain SpO2 ≥ 98%. All procedures and data collection will adhere to the approved protocol by the Ethics Committee of the Second Hospital of Shanxi Medical University (Approval No. [2026] YX No. 172). Statistical analyses will be performed using SPSS 26.0 and R software, including Spearman rank correlation, Kruskal-Wallis test, and multiple linear regression with Bootstrap validation.
- Conditions
- Difficult Airway, Intubation, Intratracheal
- Being tested
- Direct Epiglottis Elevation (Subepiglottic Method)
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Direct Epiglottis Elevation (Subepiglottic Method)Procedure or surgery
Video laryngoscopy blade tip advanced past the vallecula and placed under the laryngeal surface of the epiglottis to directly lift it.
| Study group | Role | What they receive |
|---|---|---|
| Patients Undergoing Video Laryngoscopy | Adult patients scheduled for elective general anesthesia requiring orotracheal intubation under video laryngoscopy guidance. All participants will undergo both indirect and direct epiglottis elevation techniques in a fixed sequence. Receives: Procedure: Direct Epiglottis Elevation (Subepiglottic Method) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Peak Lifting Force with Direct Epiglottis Elevation
Peak lifting force (gf) measured by a resistive thin-film pressure sensor attached to the video laryngoscope blade during the direct (subepiglottic) technique.
Measured: Perioperative
Peak Lifting Force with Indirect Epiglottis Elevation
Peak lifting force (gf) measured by a resistive thin-film pressure sensor attached to the video laryngoscope blade during the indirect (vallecula) technique.
Measured: Perioperative
POGO Score with Indirect Epiglottis Elevation
Percentage of Glottic Opening (POGO) score assessed via video laryngoscopy using the indirect (vallecula) technique. The scale ranges from 0% to 100%, where higher scores indicate better visualization of the glottis (better outcome).
Measured: Perioperative
POGO Score with Direct Epiglottis Elevation
Percentage of Glottic Opening (POGO) score assessed via video laryngoscopy using the direct (subepiglottic) technique. The scale ranges from 0% to 100%, where higher scores indicate better visualization of the glottis (better outcome).
Measured: Perioperative
Secondary outcomes (2)
Delta POGO (ΔPOGO)
Measured: Perioperative
Incidence of Difficult Glottic Exposure
Measured: Perioperative
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted29 Sep 2026
- Study start1 Oct 2026 (estimated)
- Primary completion1 Apr 2027 (estimated)
- Study completion1 Jun 2027 (estimated)
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.
- 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
- 200 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Second Hospital of Shanxi Medical University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Zheng Guo, Second Hospital of Shanxi Medical University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07846748
- Sponsor's protocol ID
- [2026]YX172
- Status last verified
- Sep 2026
- First submitted
- 16 Sep 2026
- Last updated
- 29 Sep 2026
- Results posted
- 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 29 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Correlation Between Bedside Anatomical Indicators and Lifting Force and Glottic Exposure Under Different Video Laryngoscopy Techniques
- ClinicalTrials.gov ID
- NCT07846748
- Acronym / sponsor ID
- [2026]YX172
- Conditions
- Difficult Airway, Intubation, Intratracheal
- Study type
- Observational
- Recruitment status
- Not yet recruiting
- Enrolment
- 200 participants (estimated)
- Lead sponsor
- Second Hospital of Shanxi Medical UniversityUniversity, hospital or other
- Study start
- 1 Oct 2026 (estimated)
- Primary completion
- 1 Apr 2027 (estimated)
- Study completion
- 1 Jun 2027 (estimated)
- First posted
- 29 Sep 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.
This single-center prospective observational study plans to enroll 196 patients undergoing elective general anesthesia. The study aims to investigate the correlation between preoperative bedside anatomical indicators (including modified Mallampati classification, upper lip bite test, mouth opening, head circumference, and thyromental distance) and the peak lifting force applied during video laryngoscopy, as well as the degree of glottic exposure (POGO score). The study will also evaluate the potential benefit of the direct epiglottis elevation technique in specific anatomical subgroups. After anesthesia induction, the same anesthesiologist will perform video laryngoscopy using two distinct techniques in a fixed sequence: the indirect (vallecula) method and the direct (subepiglottic) method. Peak lifting force will be quantitatively measured in real-time using a resistive thin-film pressure sensor attached to the laryngoscope blade. The primary outcomes are the POGO scores and peak lifting forces under both techniques. The secondary outcome includes the change in POGO score (ΔPOGO) between techniques. The study will provide quantitative evidence regarding the "anatomy-force-view" relationship and aid in individualized clinical decision-making for video laryngoscopy intubation.
Detailed description
This study is a single-center, prospective, observational study. A total of 196 adult patients scheduled for elective surgery under general anesthesia requiring orotracheal intubation will be enrolled. Preoperative bedside anatomical assessment will be performed by a standardized, blinded evaluator. The assessed indicators include mouth opening, thyromental distance, modified Mallampati classification, upper lip bite test, head circumference, and neck circumference. After standard anesthesia induction, video laryngoscopy will be performed by an experienced anesthesiologist. Two techniques will be evaluated in a fixed sequence: (1) Indirect epiglottis elevation (vallecula method): the blade tip is placed in the vallecula to indirectly elevate the epiglottis by lifting the tongue base. (2) Direct epiglottis elevation (subepiglottic method): the blade tip is advanced past the vallecula and placed directly under the laryngeal surface of the epiglottis to actively lift it. A resistive thin-film pressure sensor attached to the video laryngoscope blade will continuously record real-time force data, and the peak lifting force will be extracted for analysis. Glottic exposure will be evaluated using the Percentage of Glottic Opening (POGO) score. Between the two assessments, mask ventilation will be performed for at least 2 minutes to maintain SpO2 ≥ 98%. All procedures and data collection will adhere to the approved protocol by the Ethics Committee of the Second Hospital of Shanxi Medical University (Approval No. [2026] YX No. 172). Statistical analyses will be performed using SPSS 26.0 and R software, including Spearman rank correlation, Kruskal-Wallis test, and multiple linear regression with Bootstrap validation.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Patients Undergoing Video Laryngoscopy | – | Procedure: Direct Epiglottis Elevation (Subepiglottic Method)Adult patients scheduled for elective general anesthesia requiring orotracheal intubation under video laryngoscopy guidance. All participants will undergo both indirect and direct epiglottis elevation techniques in a fixed sequence. |
Who may qualify
- Ages
- 18 to 75 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- Adult patients aged 18 to 75 years with ASA physical status I to III who are scheduled for elective surgery under general anesthesia requiring orotracheal intubation under video laryngoscopy guidance. Patients with known difficult airway, facial or neck abnormalities affecting landmark palpation, limited mouth opening (< 2.0 cm), or edentulism are excluded.
Key inclusion criteria (4 listed)
- - Age 18 to 75 years
- ASA physical status I to III
- Scheduled for orotracheal intubation under video laryngoscopy guidance
- Written informed consent obtained
Key exclusion criteria (4 listed)
- Known history of difficult airway or anticipated need for awake intubation
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 |
|---|---|---|
| Direct Epiglottis Elevation (Subepiglottic Method)Video laryngoscopy blade tip advanced past the vallecula and placed under the laryngeal surface of the epiglottis to directly lift it. | Procedure or surgery | Patients Undergoing Video Laryngoscopy |
Primary outcome
Peak Lifting Force with Direct Epiglottis Elevation
Time frame: Perioperative
Peak lifting force (gf) measured by a resistive thin-film pressure sensor attached to the video laryngoscope blade during the direct (subepiglottic) technique.
Peak Lifting Force with Indirect Epiglottis Elevation
Time frame: Perioperative
Peak lifting force (gf) measured by a resistive thin-film pressure sensor attached to the video laryngoscope blade during the indirect (vallecula) technique.
POGO Score with Indirect Epiglottis Elevation
Time frame: Perioperative
Percentage of Glottic Opening (POGO) score assessed via video laryngoscopy using the indirect (vallecula) technique. The scale ranges from 0% to 100%, where higher scores indicate better visualization of the glottis (better outcome).
POGO Score with Direct Epiglottis Elevation
Time frame: Perioperative
Percentage of Glottic Opening (POGO) score assessed via video laryngoscopy using the direct (subepiglottic) technique. The scale ranges from 0% to 100%, where higher scores indicate better visualization of the glottis (better outcome).
2 secondary outcomes
Delta POGO (ΔPOGO)
Time frame: Perioperative
Incidence of Difficult Glottic Exposure
Time frame: Perioperative
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 29 Sep 2026.
- 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.
Questions about this trial
What is this clinical trial studying?
An observational study of Difficult Airway and Intubation, Intratracheal, run by Second Hospital of Shanxi Medical University.
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: opening soon, as of the sponsor's last update on 29 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
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 Jin (+86-18235572836, 1806442507@qq.com), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Peak Lifting Force with Direct Epiglottis Elevation (time frame: Perioperative). 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 29 Sep 2026.