**2.5 Airway endoscopy and trans-nasal tracheoscopy (TNT)**

It is a form of indirectly visualizing the airway and larynx in which the clinician does not directly view the lower part of the airway or larynx [4]. Instead, it is visualized with fiber optic or digital laryngoscopes inserted trans-nasally.

The images from the scope can be displayed on a monitor for the clinician, patient and others to view at the time of the procedure; it can also be recorded. Experienced clinicians can also perform it on a wake tracheoscopy using local anesthesia on cooperative patients. They are an essential tool for identifying and planning strategies for management of difficult airway cases [5] (**Figure 4**).
