Using the Glidescope as an intubation technique requires maneuvering around the curvature of the tongue and hypopharynx, in a path similar to that created by the curve of the Glidescope blade. A tube and stylet of 70-90 degrees, however, cannot be rotated around the tongue and passed into the trachea. This severe a bend angle hits the anterior trachea at too steep an angle to advance. The tip of the tube catches on the first and second tracheal rings and will not pass.
Endotracheal tube placement with the Glidescope is best done as a two-step process. The tip of the tube should be inserted into the larynx only, then the stylet partially withdrawn, before the tube is fully advanced.
It is very important that operators directly observe insertion of the tracheal tube and stylet into the mouth and around the tongue. If the operator only watches the video screen, there is a potential for damaging the hypopharynx (and perforating the airway) on initial tube insertion. Once the tube and stylet are brought around the base of the tongue, the tube tip will be visible on the monitor, and the tip can be inserted into the larynx. The stylet is partially withdrawn at this point. The distal end of the tracheal tube, now without the stiffening stylet, can then be advanced fully into the trachea. Sometimes, it will be helpful to rotate the tracheal tube toward the patient’s right side as it is advanced (clockwise). This is because clockwise rotation of a left-facing beveled tube will turn the bevel upward, disengaging the leading edge of the tube from the anterior tracheal rings.
Although the tube delivery issues can be overcome using standard equipment, the manufacturer now produces a custom designed stylet (The GlideRite Stylet) and also has special tracheal tubes (made by Parker Medical, the GlideRite Tube) that eliminate the difficulties that can occur using standard stylets and left-facing beveled tubes.
The GlideRite Stylet is a rigid stainless steel stylet with a large plastic proximal stop. It fits tracheal tubes 6.0 mm and larger and can be autoclaved 250 times. The proximal stop allows for partial withdrawal of the stylet with a single hand technique. With the Glidescope in the operator’s left hand, and the tracheal tube and underlying GlideRite stylet grasped at the proximal part of the tube, the thumb can push the stylet partially out from the tube (after the larynx is entered). An assistant (or the operator if they release the Glidescope blade) can then advance the tube fully into the trachea (and rotate the stylet out).
The GlideRite Tube is manufactured by Parker Medical for Verathon. It uses Parker’s innovative ski-tip design. This tip does not engage the anterior tracheal rings as a standard level-facing beveled tube does. The soft tip of the Parker tube glides over the tracheal rings and eliminates the need for turning the tube rightward (clockwise) to rotate the bevel upward.
Click here for more information on how left-facing beveled tubes interact with the tracheal rings