An unanticipated difficult airway is a potentially life-threatening event during elective surgery or management of critical conditions. However, the common clinical screening tests, show low sensitivity and specificity with a limited predictive value. Recently, ultrasound has been used to identify difficult airway. Tongue volume is one of the parameters evaluated by ultrasound. In this study, we aim to evaluate the capacity of mid-sagittal tongue CSA and tongue width to predict difficult laryngoscopy and difficult intubation.

Anatomical changes that adversely affect airway accessibility due to increased adipose tissue in obese patients make it difficult to establish an advanced airway by orotracheal intubation. Difficulty with airway management for anesthesia has potentially serious implications, as failure to secure a patent airway can result in hypoxic brain injury or death in a matter of minutes. There have been no effective methods to predict difficult airways accurately. Ultrasonography is a non-invasive, safe, and painless modality for evaluating soft tissues. In recent years, studies have been carried out on the parameters that can be used in determining the difficult airway with ultrasound. These include the distance from the skin to the epiglottis, the tongue thickness, the tongue volume, the mandibular condylar mobility, and the visibility of the hyoid. Few studies have whether midsagittal tongue cross section area and tongue width can also be used to predict difficult airways similarly to tongue volume. Therefore, this study was designed to evaluate the predictive value of accurately measured tongue thickness and cross-sectional tongue area using ultrasonography for predicting difficult tracheal intubation and difficult laryngoscopy.

Inclusion Criteria:

• American Society of Anesthesiologists (ASA) physical condition I-II-III
• Patients are required general anesthesia with tracheal intubation for bariatric surgery.

Exclusion Criteria:

• Patients with maxillofacial deformity, trauma, or tumor
• Patients with identified difficult airway or difficult airway history
• Patients with cancellation of tracheal intubation for a non-difficult airway reason

Patients who are18 to 90 years old and of either sex who required general anesthesia with tracheal intubation for bariatric surgery .