To assess whether the thickness of pre-tracheal fat, greater than 28 mm, and measured by ultrasound, constitutes a reliable parameter in the prediction of a difficult airway.

Inclusion Criteria:

• Patients risk ASA I-IV
• Non-urgent surgery under general anesthesia with orotracheal intubation
• Acceptance to participate and grant written consent

Exclusion Criteria:

• Urgent surgery
• Patients with a history of craniocervical pathology (trauma, tumor, malformations)
• Pregnancy
• Patient Refusal

Patients under general anesthesia with orotracheal intubation