Ultrasound-Based Airway Assessment for Predicting Difficult Intubation in Adult Female Patients

This is a prospective, single-center observational study conducted in adult female patients scheduled for elective surgery under general anesthesia. The study was performed at the University of Health Sciences Adana City Training and Research Hospital after approval by the institutional ethics committee.

Before induction of anesthesia, standardized ultrasonographic airway assessments were performed by an experienced anesthesiologist. Measurements included tongue thickness, the distance from the skin to the anterior commissure of the vocal cords, the distance from the skin to the hyoid bone, and the distance from the skin to the epiglottis. All measurements were obtained under static pre-induction conditions using portable ultrasound equipment.

Following anesthesia induction, direct laryngoscopy was performed, and laryngoscopic view was graded according to the Cormack-Lehane classification. Difficult intubation was defined based on predefined laryngoscopic criteria. Ultrasonographic measurements were then analyzed for their diagnostic performance in predicting difficult intubation.

The primary objective of the study was to determine the most informative ultrasonographic parameter for predicting difficult intubation in this population. Secondary objectives included comparing the relative diagnostic value of different ultrasound measurements and evaluating their potential role in routine preoperative airway assessment.

Inclusion criteria

• Female patients aged 18-65 years
• American Society of Anesthesiologists (ASA) physical status I-III physical status I-III
• Scheduled for elective surgery under general anesthesia requiring tracheal intubation
• Ability to provide informed consent

Exclusion criteria

• Body mass index ≥30 kg/m²
• Known history of difficult intubation
• Anatomical airway abnormalities or head and neck pathology
• Pregnancy
• Emergency surgery