This study is designed to identify patients' features predictive of difficult endotracheal intubation using a flexible fiberscope.

Endotracheal intubation is an important act in the practice of anesthesiology. Direct laryngoscopy is the most commonly used technique to accomplish this task. Airway characteristics predicting difficult intubation with direct laryngoscopy are well defined. Physical findings, such as Mallampati classification or measurements of the thyromental distance, mouth opening, and neck extension have been validated to help anticipate difficult situations with the direct laryngoscope. When direct laryngoscopy is difficult, early conversion to an alternative technique reduces the risk of airway compromise and associated morbidity.

Many alternative intubation devices are now available, and part of the anesthesiologist's task is to select the alternative approach best suited to each patient's specific features. Despite its use for both elective and unexpectedly difficult intubation, predictive criteria for successful airway management with the flexible fiberscope have not been developed.

The purpose of this study is to identify patient morphometric or morphological characteristics, if any, that could predict difficult intubation when using the flexible fiberscope for perioperative tracheal intubation in an elective surgical population.

Inclusion Criteria:

• Age 18 and older
• Patients undergoing elective surgery under general anesthesia, requiring endotracheal intubation

Exclusion Criteria:

• Induction planned without neuromuscular blocking agents
• Need for a rapid sequence induction