Comparison of Airway Ultrasonography and Laryngoscopy Methods in Obese Patients

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.

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.