There are two methods of nasal flexible fiberoptic technique: (1) scope first and (2) tube first (Figs. 22.71 and 22.72).
Scope-First Method. The ETT is placed at the proximal extreme. The endoscope is then guided to the glottic opening, and the tube is then advanced over the endoscope. (Photo contributor: Lawrence B. Stack, MD.)
Tube-First Method. The ETT is advanced to the hypopharynx. The endoscope is then advanced through the tube and maneuvered to the glottic opening. The tube is then advanced over the endoscope. (Photo contributor: Lawrence B. Stack, MD.)
The nares should be inspected for patency and the side deemed most hospitable to tube passage should be anesthetized and vasoconstricted, additionally, it is helpful to confirm nasal patency by inserting a well lubricated nasal trumpet. Lidocaine jelly can be used as the lubricant to provide additional topical anesthesia. We favor the use of disposable atomizers to instill 2 ml of a mixture of tetracaine 1% phenylephrine 0.5%, which yields excellent mucosal anesthesia and vasoconstriction. Favorable intubation conditions can be achieved in about 5 minutes.
In preparation for nasal intubation, the ETT can be conformed into a circle by inserting the tip into the 15 mm proximal adaptor, and soaked in warm water to soften the tube for nasal passage.
The largest possible ETT, preferably 7.0-mm ID, is inserted over the endoscope to the most proximal position of the endoscope. The fiberoptic endoscope is then inserted through the selected naris. Under direct visual guidance, the endoscope is advanced along the floor of the nose, navigating under the inferior turbinate. The endoscope tip is manipulated by a combination of trigger deflection (up/down) and scope rotation (left/right) to keep the lumen in the center of the optical field. As the tube is advanced to the posterior nasopharynx, the scope tip is deflected downward to reveal the epiglottis and laryngeal inlet. The scope is advanced further, with the operator maneuvering the scope tip to keep the glottic opening in the center of the optical field. With the endoscope tip just above the cords, 2 mL of 1% lidocaine should be injected through the injection port of the fiberscope to provide vocal cord anesthesia prior to tube passage. The endoscope advancement continues until the endoscope tip is approximately 3 to 5 cm above the carina. The tube is then gently advanced over the fiberoptic sheath into the naris and to the trachea. If resistance is encountered at 14 to 16 cm, the tube may be impacting upon the right arytenoid. As discussed previously, this can be corrected by a severe counterclockwise rotation. The tube tip should be verified to be ...