Comparison of Airway Ultrasonography and Laryngoscopy Methods in Obese Patients

Official title

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

Overview

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.

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.

Interventions

• 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 air
• Device Macintosh Laryngoscope Intubation
  Endotracheal intubation will be performed using a conventional Macintosh direct laryngoscope under standardized general anesthesia induction.
• Device Tuoren Videolaryngoscope Intubation
  Endotracheal intubation will be performed using the Tuoren videolaryngoscope under standardized general anesthesia induction.
• Device Besdata Videolaryngoscope Intubation
  Endotracheal intubation will be performed using the Besdata videolaryngoscope under standardized general anesthesia induction.

Primary outcome measures

• Prediction of difficult tracheal intubation [Time frame: Periprocedural (during tracheal intubation)]
• Tracheal intubation success according to laryngoscope type [Time frame: During the tracheal intubation procedure]

Secondary outcome measures (6)

• Glottic visualization time [Time frame: Periprocedural (during tracheal intubation)]
• Endotracheal intubation time [Time frame: Periprocedural (during tracheal intubation)]
• Hemodynamic response to tracheal intubation [Time frame: Periprocedural]
• Postoperative airway ultrasonographic measurements [Time frame: 30 minutes after extubation]
• Airway-related postoperative complications [Time frame: From intubation to 30 minutes postoperatively]
• Anesthesiologist satisfaction score [Time frame: Immediately after tracheal intubation]

Eligibility criteria

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.

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Allocation

Randomized

Model

Parallel assignment

Masking

Open label

Primary purpose

Diagnostic

Study locations

Turkey (Türkiye) · 1 center

• Trabzon University Faculty of Medicine Kanuni Training and Research Hospital — Trabzon

Publications

• Sotoodehnia M, Abbasi N, Bahri RA, Abdollahi A, Baratloo A. Accuracy of airway ultrasound parameters to predict difficult airway using the LEMON criteria as a reference: A cross-sectional diagnostic accuracy study. Turk J Emerg Med. 2023 Jan 2;23(1):38-43. doi: 10.4103/2452-2473.366484. eCollection 2023 Jan-Mar. PMID 36818949
• Wang X, Wang Y, Zheng ZW, Liu YR, Ma WH. Ultrasound measurements for evaluation of changes in upper airway during anaesthesia induction and prediction difficult laryngoscopy: a prospective observational study. Sci Rep. 2022 Nov 3;12(1):18564. doi: 10.1038/s41598-022-21695-2. PMID 36329088
• Ramesh K, Srinivasan G, Bidkar PU. 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. Cureus. 2023 Aug 14;15(8):e43471. doi: 10.7759/cureus.43471. eCollection 2023 Aug. PMID 37711910

Identifiers

NCT: NCT07482436 · TrabzonMF

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗