Airway Ultrasound vs Clinical Predictors for Difficult Airway

NCT07243106 | Enrolling By Invitation

• 1 other identifier: 25-MOBAEK-329
• Study Type: observational
• Target: 140
• Locations: 1 country
• Sites: 1

Brief Summary

This prospective observational study aims to evaluate the diagnostic value of airway ultrasonography in predicting difficult intubation in adult patients undergoing elective surgery under general anesthesia. Preoperative sonographic measurements of upper airway structures will be compared with conventional clinical airway assessment parameters such as the Mallampati score, thyromental distance, and sternomental distance. The study seeks to determine whether ultrasonographic measurements can serve as independent predictors of difficult airway and whether combining them with clinical parameters improves diagnostic accuracy. Additionally, the correlation between sonographic findings and the Intubation Difficulty Scale (IDS) will be analyzed to assess the potential clinical utility of airway ultrasound in preoperative airway evaluation.

Conditions

Ultrasonography; Difficult Airway; Preoperative Evaluation

Outcome Measures

Primary Outcomes (2)

• The Intubation Difficulty Scale (IDS)

  The Intubation Difficulty Scale (IDS) is a quantitative scoring system used to objectively assess the complexity of tracheal intubation. It incorporates seven parameters: number of intubation attempts, number of operators, number of alternative techniques used, Cormack-Lehane grade, lifting force required, necessity of external laryngeal pressure, and position of the vocal cords. The total IDS score is calculated as the sum of these variables, providing a numerical indicator of intubation difficulty (IDS = 0 indicates easy intubation; IDS = 1-5 mild to moderate difficulty; IDS \> 5 difficult intubation).

  During tracheal intubation (approximately 1-3 minutes after induction of anesthesia)

• Difficulty of mask ventilation

  After standard induction of anesthesia, all patients will be ventilated via face mask for 2 minutes, followed by tracheal intubation using a Macintosh laryngoscope. The difficulty of mask ventilation will be assessed using the Han Mask Ventilation Scale, defined as follows: Class 1: Mask ventilation possible Class 2: Mask ventilation possible with the use of an oral airway or other adjuncts Class 3: Mask ventilation possible only with the assistance of a second person Class 4: Mask ventilation impossible

  During 2-minute face mask ventilation after induction of anesthesia

Study Arms (1)

Adult patients scheduled for elective surgery under general anesthesia with endotracheal intubation

Demographic data of all participants-including age, sex, type of planned surgery, ASA physical status, and comorbidities-will be recorded. Before induction of anesthesia, all patients will be evaluated using standard clinical airway assessment parameters. These include the Mallampati score, thyromental distance, sternomental distance, neck circumference, and upper lip bite test. Body mass index (BMI) and waist-to-hip ratio will also be measured and documented. In the preoperative period, all patients will undergo airway ultrasonography performed by an anesthesiologist. Sonographic assessments will be carried out by a single experienced anesthesiologist using a linear transducer, with the patient positioned in the sniffing position. The following ultrasound measurements will be obtained and recorded: Skin-to-epiglottis distance, skin-to-hyoid bone distance, skin-to-anterior commissure of the vocal cords distance, skin-to-trachea distance at the suprasternal notch level.

Eligibility Criteria

• Age: 18 Years - 60 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)
• Sampling Method: Non-Probability Sample

Study Population

Adult patients aged 18-60 years, classified as ASA I-III, scheduled for elective surgery under general anesthesia with planned endotracheal intubation. Both male and female patients meeting inclusion criteria and without any exclusion criteria (emergency surgery, known difficult intubation, head/neck trauma, prior head/neck surgery or malignancy, pregnancy) will be eligible for enrollment.

You may qualify if:

• Adult patients aged 18-60 years
• Scheduled for elective surgery
• ASA (American Society of Anesthesiologists) physical status I, II, or III
• Planned for endotracheal intubation under general anesthesia

You may not qualify if:

• Patients requiring emergency surgery
• Patients with a known history of difficult intubation
• Patients with head or neck trauma
• Patients with a history of previous head or neck surgery or head/neck malignancy
• Pregnant patients

Sponsors & Collaborators

• Tokat Gaziosmanpasa University: lead

Study Sites (1)

Tokat Gaziosmanpasa University

Tokat Province, Tokat Province, 60100, Turkey (Türkiye)

Location

Study Design

• Study Type: observational
• Observational Model: OTHER
• Time Perspective: OTHER
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant professor

Study Record Dates

• First Submitted: November 17, 2025
• First Posted: November 21, 2025
• Study Start: December 20, 2025
• Primary Completion (Estimated): June 1, 2026
• Study Completion (Estimated): September 1, 2026
• Last Updated: March 10, 2026

Record last verified: 2025-11

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP

Locations

TU (1)