Ultrasound Measurement of Skin-to-Epiglottis Distance for Prediction of Difficult Airway in Adult Patients

July 16, 2026 updated by: Almıla Gulsun Pamuk, Hacettepe University

Ultrasound Measurement of Skin to Epiglottis Distance for Prediction of Difficult Airway in Adult Patients

This prospective observational study aims to evaluate the predictive value of ultrasound-measured skin to epiglottis distance for difficult airway in adult patients undergoing elective or emergency procedures requiring airway management. The correlation between ultrasound measurements and standard airway assessment parameters will be analyzed.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Not yet recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Detailed Description

Airway management is a critical component of anesthesia and intensive care practice. Predicting difficult airway remains challenging with conventional bedside tests. Ultrasound has emerged as a non-invasive, bedside tool for airway assessment. This study aims to investigate the relationship between skin-to-epiglottis distance measured by ultrasound and difficult laryngoscopy/intubation. Secondary comparisons will include traditional airway assessment methods such as Mallampati score, thyromental distance, and neck circumference

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
300

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.
  • Name: Almıla G Pamuk, Doç. Dr.
  • Phone Number: 03123051207 9005335296325
  • Email: gulsunp@yahoo.com

Study Contact Backup

  • Name: muhammed r hız, research assistant
  • Phone Number: 9003123051207 9005417800327
  • Email: drrasithiz@gmail.com

Study Locations

  • Turkey (Türkiye)
    • Altındağ
      • Ankara, Altındağ, Turkey (Türkiye), 06320
        • Hacettepe Univercity

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Sampling Method

Probability Sample

Study Population

The study population consists of adult patients scheduled for elective surgery requiring tracheal intubation under general anesthesia. Patients will be recruited from the preoperative anesthesia clinic at [Hacettepe University Faculty of Medicine]

Description

Inclusion Criteria:

  • ≥18 yaş elective surgery

Exclusion Criteria:

  • emergency surgery
  • head and neck surgery
  • pregnant patients

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Skin to epiglottis distance
Time Frame: Preintubation (within 30 minutes before procedure)
Distance measured via ultrasound in the anterior neck region
Preintubation (within 30 minutes before procedure)

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Incidence of difficult laryngoscopy (Cormack-Lehane grade ≥ 3)
Time Frame: During intubation procedure (intraoperative period)
The proportion of patients with difficult laryngoscopy defined as Cormack-Lehane grade 3 or 4 during direct laryngoscopy.
During intubation procedure (intraoperative period)
Intubation Difficulty Score (IDS)
Time Frame: During intubation procedure
Assessment of intubation difficulty using the Intubation Difficulty Score based on number of attempts, operators, alternative techniques, glottic exposure, lifting force, external laryngeal pressure, and vocal cord position.
During intubation procedure
Correlation between ultrasound measurements and Mallampati score
Time Frame: Preoperative assessment
Correlation between tracheal diameter and skin to epiglottis distance measured by ultrasound and preoperative Mallampati classification.
Preoperative assessment
Skin-to-Epiglottis Distance Measured by Ultrasound
Time Frame: Immediately before induction of anesthesia
Skin-to-epiglottis distance will be measured using ultrasound immediately before anesthesia induction. The distance is recorded in millimeters (mm) as a continuous variable. Larger values indicate a greater skin-to-epiglottis distance and may be associated with an increased likelihood of difficult laryngoscopy. This is not a scored scale; therefore, no predefined minimum or maximum score exists.Cormack-Lehane Grading System. Scores range from Grade I to Grade IV. Grade I indicates full visualization of the glottis (easier laryngoscopy), whereas Grade IV indicates that neither the glottis nor the epiglottis is visible (most difficult laryngoscopy). Higher grades indicate a worse airway view.
Immediately before induction of anesthesia

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Hacettepe University

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Study Director: Almıla g Pamuk, Doç Dr., Hacettepe Univercity

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Estimated)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
July 1, 2026

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
November 1, 2026

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 4, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
May 20, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
May 20, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
May 27, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
July 17, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 16, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
July 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • SBA 26/158

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Diffuculty airway

IPD Sharing Time Frame

10/2026 -- 01/2027

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF
  • ANALYTIC_CODE
  • CSR

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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