This prospective observational study aims to evaluate the relationship between preoperative ultrasonographic airway measurements and the Video-Intubation Difficulty Assessment Classification (VIDIAC) score in adult patients undergoing endotracheal intubation under general anesthesia. The study will investigate whether airway ultrasound parameters can predict difficult videolaryngoscopic intubation and assess their association with the Cormack-Lehane classification, intubation time, and other airway management outcomes.

Difficult airway management is a major cause of anesthesia-related morbidity and mortality. Airway ultrasonography has emerged as a noninvasive tool for evaluating airway anatomy and may help predict difficult intubation. The Video-Intubation Difficulty Assessment Classification (VIDIAC) score is a recently developed and standardized method for assessing videolaryngoscopic intubation difficulty.

This prospective, observational, single-center study aims to evaluate the relationship between preoperative ultrasonographic airway measurements and the VIDIAC score in adult patients undergoing elective surgery under general anesthesia. Ultrasonographic measurements, including tongue depth, tongue thickness, hyomental distance, hyoid depth, hyoid width, and distance from skin to epiglottis, will be obtained before anesthesia induction.

Videolaryngoscopic intubation will be performed by anesthesiologists blinded to the ultrasound findings, and the VIDIAC score will be recorded. The study will assess the correlation between ultrasonographic airway measurements and the VIDIAC score, as well as the ability of these measurements to predict difficult videolaryngoscopic intubation.

Inclusion Criteria:

• Adults aged 18 to 80 years.
• American Society of Anesthesiologists (ASA) physical status I-III.
• Patients scheduled for endotracheal intubation under general anesthesia.
• Patients who provide written informed consent.

Exclusion Criteria:

• Known airway abnormalities.
• Head and neck tumors.
• Patients with a tracheostomy.
• Pregnant patients.
• Emergency surgical procedures.
• Patients with limited cervical mobility.
• Patients with facial trauma.

The study population will consist of adult patients aged 18-80 years who are scheduled to undergo elective surgical procedures requiring endotracheal intubation under general anesthesia at Samsun City Hospital. Eligible patients with ASA physical status I-III who provide written informed consent and meet all inclusion criteria will be consecutively enrolled in the study.

The datasets used and/or analysed during the current study are available from the corresponding author on reasonable request.