Comparison of Airway Ultrasonography and Laryngoscopy Methods in Obese Patients

The Effect of Preoperative and Postoperative Airway Ultrasonography and Different Laryngoscope Uses on Intubation Success and Postoperative Complications in Obese Patients

The main objective of this study was to examine the relationship between classical markers used in assessing difficult airway management in obese patients (Mallampati score, thyromental distance, sternomental distance, neck circumference measurement) and ultrasonographic parameters (vocal cord mobility, glottic opening, hyomental distance, skin-epiglottic distance, and peri-epiglottic space-epiglottic-vocal cord ratio), to compare the effects of these parameters on predicting difficult intubation, and to investigate the effects of different laryngoscopy methods on intubation success and peroperative respiratory complications.

The secondary objective of the study is to investigate the effects of different laryngoscopy methods on hemodynamic responses to intubation. Participants' gender, age, height, weight, BMI, ASA physical status classification, smoking status, comorbidities, STOP-BANG and LEMON scores will be recorded. The glottic score percentage (POGO score), glottic visualization time, endotracheal intubation time, use of assistive maneuvers, and Intubation Difficulty Scale (IDS) parameters will be compared according to the laryngoscopy methods used.

Participants must meet the following criteria:

• Consent given by the patient
• Operated under general anesthesia
• Over 18 years of age
• American Society of Anesthesiologists (ASA) physical status classification I-II-III
• Body mass index (BMI) of 30 kg/m2 or higher
• Operation duration between 60-150 minutes
• Patients undergoing elective surgery.

Study Overview

• Status: Recruiting
• Conditions: Correlation of Difficult Airway Markers With Ultrasonographic Measurements in Obese Patients
• Intervention / Treatment: Procedure: Airway ultrasonography; Device: Besdata Videolaryngoscope Intubation; Device: Tuoren Videolaryngoscope Intubation; Device: Macintosh Laryngoscope Intubation

Detailed Description

Unanticipated morbidity related to difficult airway management remains a major concern for anesthesiologists. One of the primary reasons is the high interobserver variability and limited predictive power of currently used bedside airway assessment tests. The use of more objective and reproducible measurement techniques may improve intubation success rates and allow better preparation in cases of anticipated difficult airway.

Ultrasonography (USG) is a rapid, non-invasive, portable imaging modality that provides both static and dynamic real-time visualization. Airway ultrasonography is increasingly used in operating rooms, intensive care units, and emergency departments for detailed assessment of airway anatomy. It provides valuable information regarding upper airway structures, soft tissues of the head and neck, and pretracheal anatomy.

Preoperative airway assessment is the first and most critical step in preventing anesthesia-related airway complications. Recent evidence suggests that incorporating airway ultrasound into routine pre-anesthetic evaluation may improve the prediction of difficult airway compared to conventional clinical assessments alone.

With the global increase in obesity prevalence, anesthesiologists are encountering a growing number of obese patients in daily practice. Numerous studies have identified male sex, advanced age, increased neck circumference, higher body mass index (BMI), obstructive sleep apnea syndrome, higher Mallampati score, higher ASA score, and shorter thyromental distance as predictors of difficult intubation in obese patients. Despite these known predictors, the rate of unanticipated difficult intubation remains considerable.

Videolaryngoscopes have demonstrated high success rates in both anticipated and unanticipated difficult airway scenarios. These devices improve glottic visualization and may increase first-pass intubation success while reducing airway-related complications. In obese patients, videolaryngoscopy may further enhance intubation safety and perioperative outcomes.

This randomized prospective study aims to compare the predictive value of conventional difficult airway markers (Mallampati score, thyromental distance, sternomental distance, and neck circumference) with airway ultrasonographic parameters (vocal cord mobility, glottic opening, hyomental distance, skin-to-epiglottis distance, and peri-epiglottic space-epiglottis-vocal cord ratio) in obese patients undergoing elective surgery under general anesthesia.

Additionally, the study will evaluate the effects of three different laryngoscopy methods (Macintosh direct laryngoscope, Tuoren videolaryngoscope, and Besdata videolaryngoscope) on intubation success, perioperative respiratory complications, and hemodynamic responses. Postoperative airway ultrasonography will be performed to assess potential airway-related complications.

• Study Type: Interventional
• Enrollment (Estimated): 180
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Ezgi Günaydın, MD; Phone Number: +905336834198; Email: ezgunaydin@gmail.com

Study Locations

• Turkey (Türkiye)
  • Trabzon, Turkey (Türkiye), 61040
    • Recruiting
    • Trabzon University Faculty of Medicine Kanuni Training and Research Hospital
    • Contact: Recep Erin, doctor; Phone Number: +905304699135; Email: erinrecep@gmail.com

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Patients who have given their consent
• Patients who underwent surgery under general anesthesia
• Patients over eighteen years of age
• Patients with an American Society of Anesthesiologists (ASA) physical status classification of I-II-III
• Patients with a body mass index (BMI) of 30 kg/m2 or higher
• Patients whose surgery lasts between 60 and 150 minutes
• Patients who underwent surgery under elective conditions will be included.

Exclusion Criteria:

• Patients who do not consent,
• those undergoing head and neck surgery,
• those to be operated on in the prone position,
• uncooperative patients (patients with whom communication is not possible),
• those with craniofacial anomalies,
• patients operated on in emergency situations will be excluded from the study.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Diagnostic
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Besdata Videolaryngoscope; Participants randomized to this arm will undergo tracheal intubation using the Besdata videolaryngoscope under standardized general anesthesia induction.	Procedure: Airway ultrasonography; Preoperative airway ultrasonography will be performed in the waiting area before surgery to evaluate upper airway structures including vocal cord mobility, glottic opening, hyomental distance, skin-to-epiglottis distance, and peri-epiglottic space-epiglottis-vocal cord ratio. Measurements will be obtained with a Mindray Consona N7 ultrasound device while the patient is in the supine position. Each measurement will be performed three times and the average value will be recorded. Postoperative airway ultrasonography will be repeated at 30 minutes in the recovery unit.; Device: Besdata Videolaryngoscope Intubation; Endotracheal intubation will be performed using the Besdata videolaryngoscope under standardized general anesthesia induction.
Experimental: Tuoren Videolaryngoscope; Participants randomized to this arm will undergo tracheal intubation using the Tuoren videolaryngoscope under standardized general anesthesia induction.	Procedure: Airway ultrasonography; Preoperative airway ultrasonography will be performed in the waiting area before surgery to evaluate upper airway structures including vocal cord mobility, glottic opening, hyomental distance, skin-to-epiglottis distance, and peri-epiglottic space-epiglottis-vocal cord ratio. Measurements will be obtained with a Mindray Consona N7 ultrasound device while the patient is in the supine position. Each measurement will be performed three times and the average value will be recorded. Postoperative airway ultrasonography will be repeated at 30 minutes in the recovery unit.; Device: Tuoren Videolaryngoscope Intubation; Endotracheal intubation will be performed using the Tuoren videolaryngoscope under standardized general anesthesia induction.
Active Comparator: Macintosh Laryngoscope; Participants randomized to this arm will undergo tracheal intubation using a conventional Macintosh direct laryngoscope under standardized general anesthesia induction.	Procedure: Airway ultrasonography; Preoperative airway ultrasonography will be performed in the waiting area before surgery to evaluate upper airway structures including vocal cord mobility, glottic opening, hyomental distance, skin-to-epiglottis distance, and peri-epiglottic space-epiglottis-vocal cord ratio. Measurements will be obtained with a Mindray Consona N7 ultrasound device while the patient is in the supine position. Each measurement will be performed three times and the average value will be recorded. Postoperative airway ultrasonography will be repeated at 30 minutes in the recovery unit.; Device: Macintosh Laryngoscope Intubation; Endotracheal intubation will be performed using a conventional Macintosh direct laryngoscope under standardized general anesthesia induction.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Prediction of difficult tracheal intubation	Airway ultrasonographic parameters and conventional airway assessment scores will be evaluated to determine their ability to predict difficult tracheal intubation in obese patients undergoing elective surgery under general anesthesia. Difficult tracheal intubation will be defined using the Intubation Difficulty Scale (IDS).	Periprocedural (during tracheal intubation)
Tracheal intubation success according to laryngoscope type	Tracheal intubation success will be compared among patients randomized to Macintosh laryngoscope, Tuoren videolaryngoscope, and Besdata videolaryngoscope during tracheal intubation in obese patients undergoing elective surgery under general anesthesia.	During the tracheal intubation procedure

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Glottic visualization time	Glottic visualization time will be defined as the time from passage of the laryngoscope blade past the lips until the first visualization of the vocal cords during laryngoscopy. Glottic visualization time will be compared among the Macintosh laryngoscope, Tuoren videolaryngoscope, and Besdata videolaryngoscope groups.	Periprocedural (during tracheal intubation)
Endotracheal intubation time	Endotracheal intubation time will be defined as the time from passage of the laryngoscope blade past the lips until confirmation of successful tracheal intubation by capnography. Intubation time will be compared among the Macintosh laryngoscope, Tuoren videolaryngoscope, and Besdata videolaryngoscope groups.	Periprocedural (during tracheal intubation)
Hemodynamic response to tracheal intubation	Hemodynamic parameters will be recorded before anesthesia induction, 1 minute after induction, at 1, 3, 5, and 10 minutes after tracheal intubation, and immediately before extubation to evaluate the effects of different laryngoscopy techniques.	Periprocedural
Postoperative airway ultrasonographic measurements	Airway ultrasonography will be repeated 30 minutes after extubation in the recovery unit and compared with preoperative ultrasonographic measurements.	30 minutes after extubation
Airway-related postoperative complications	Airway-related complications including sore throat, hoarseness, laryngospasm, bronchospasm, hypoxemia, esophageal intubation, and oral trauma will be recorded.	From intubation to 30 minutes postoperatively
Anesthesiologist satisfaction score	Anesthesiologist satisfaction with the laryngoscope will be evaluated using a 6-item questionnaire based on a 5-point Likert scale (1 = very poor, 5 = excellent). The questionnaire will assess the ease of laryngoscope insertion, quality of glottic visualization, ease of endotracheal tube placement, device handling, need for additional maneuvers, and overall operator satisfaction.	Immediately after tracheal intubation

Collaborators and Investigators

• Sponsor: Trabzon Kanuni Education and Research Hospital

Publications and helpful links

General Publications

• Accuracy of airway ultrasound parameters to predict difficult airway using the LEMON criteria as a reference: A cross-sectional diagnostic accuracy study (DOI: 10.4103/2452-2473.366484 )
• Ultrasound measurements for evaluation of changes in upper airway during anaesthesia induction and prediction difficult laryngoscopy: a prospective observational study ( doi.org/10.1038/s41598-022-21695-2)
• Comparison of Tracheal Intubation Using King Vision (Non-channeled Blade) and Tuoren Video Laryngoscopes in Patients With Cervical Spine Immobilization by Manual In-Line Stabilization: A Randomized Clinical Trial (doi: 10.7759/cureus.43471)

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2026
• Primary Completion (Estimated): July 1, 2026
• Study Completion (Estimated): July 1, 2026

Study Registration Dates

• First Submitted: March 4, 2026
• First Submitted That Met QC Criteria: March 14, 2026
• First Posted (Actual): March 19, 2026

Study Record Updates

• Last Update Posted (Actual): March 19, 2026
• Last Update Submitted That Met QC Criteria: March 14, 2026
• Last Verified: March 1, 2026

More Information

Terms related to this study

• Keywords: difficult airway; laryngoscopy; obese patients; airway ultrasonography
• Other Study ID Numbers: TrabzonMF

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: I plan to share the results after the research is complete.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No