Laryngeal Exposure Tube Delivery

Other Right Angled Imaging Devices

Every video or other right-angled imaging device has its own issues and subtleties regarding tube insertion and delivery into the trachea.  The devices not specifically listed at left (McGrath, Pentax Airway Scope) have similar issues to the Glidescope or the AirTraq, respectively, which are separately addressed (menu to left).

It is critical for airway managers to be familiar with each device they use because in many instances of emergency airway management in particular patients will have very short safe apnea times. Some studies investigating video intubation devices have found prolonged intubation times despite very rapid laryngeal exposure. This is not a “device problem,” per se, but rather shows that operators cannot quickly intubate without a specific understanding of the tube delivery issue with a given device.

The McGrath laryngoscope has similar tube delivery issues to the Glidescope in that both devices involve free handing a tube around the tongue (at a sharp angle) and into the trachea. Glidescope offers a special stylet designed for this purpose, which makes tube insertion into a two step process; first the tube tip is inserted into the larynx, and second, the stylet is withdrawn partially before full insertion of the tracheal tube into the trachea. A malleable stylet can be used in the same fashion, although the stiffer steel stylets are much better for this purpose than the aluminum plastic covered stylets.

Both the Glidescope and McGrath scopes have been associated with airway trauma (perforation of the pharynx, soft palate, etc.) when operators focus only on the video screen and are not careful about stylet insertion into the mouth.  A styletted tube should be directly observed passing about the curve of the tongue, before the operator moves their view to the video screen.  As with direct laryngoscopy stylet shaping, the stylet should not go beyond the distal cuff of the trachea tube, otherwise it adds too much rigidity the distal tip.

Cooper RM. Complications associated with the use of the GlideScope videolaryngoscope. Can J Anaesth. 2007 Jan;54(1):54-7.

Williams D, Ball DR. Palatal perforation associated with McGrath videolaryngoscope.  Anaesthesia. 2009 Oct;64(10):1144-5.

The Pentax Airway Scope has a track similar to the AirTraq, and this influences the direction that the tracheal tube moves out from the device.  In order to alter the tube direction, the device (with the tube in the track) must be adjusted; the tube itself cannot be directed independently.  Tube delivery and targeting with the Airway Scope is enhanced, though, by target sighting marks on the video screen.