“Dual endoscopy” refers to using two devices – usually a video laryngoscope and a rigid or flexible endoscope – to manage an airway. The Bonfils (or Shikani or Levitan) optical stylet is often used in this context. Performing dual endoscopy provides “three levels of protection”:
If the glottic opening is easily seen with the laryngoscope, the rigid endoscope simply acts as an ideally shaped or steerable stylet to introduce the tube
If the view is poor (CL grade 3 or 4), the laryngoscope can be used to guide the tip of the ETT and endoscope “into the ballpark”, and then the final positioning of the tip of the tube through the vocal cords is achieved with the endoscope.
If the airway is badly soiled or swollen (eg. ongoing bleeding or angioedema), the endoscope can be used as a lightwand for a transillumination technique. (Remember lightwands, anyone?)
Here’s a brief informal video explaining the first two points, using the CMAC VL/VS:
Another dual endoscopy approach is “VAFI” (video-assisted flexible/fibreoptic intubation), where a VL is used to help place a flexible endoscope, whereafter the rest of the intubation is continued using the flexible. Several good case reports of this technique are described in the literature.
Rigid endoscopes are very valuable tools for intubation in certain difficult scenarios, but are not commonly used in most centres. The techniques and learning curve differ significantly from normal direct laryngoscopy, requiring independent practice to become proficient. Pictured here are (left to right) a rigid bronchoscope, Bonfils, Levitan and Shikani optical stylets (rigid intubating endoscopes).
This is the set-up for basic training on an UCT Anaesthesia Airways course. Which of these devices have you used? Do you have tricks or comments to share?
Intubation in a young child with a severe submandibular abscess using the paediatric Bonfils rigid intubating endoscope under inhalational general anaesthesia. Direct laryngoscopy showed only severe swelling with a Cormack-Lehane grade 3b view. A standard laryngoscope was used with the left hand to create an open path for the Bonfils just right of the midline, avoiding the worst of the submandibular swelling. 3.5mm Bonfils allowed intubation with a 4.5 mm uncuffed ETT. Note that because this is a rigid intubating scope, it is not inserted through the vocal cords, but they are visible through the tube as it is inserted with the Bonfils held steady.
Open access meducation for all aspects of airway management