Got this email from a listener:
Merry Christmas. So here I am sitting here sipping my coffee on a quiet Christmas morning and I'm writing YOU a complete stranger, a Christmas email. Well not a complete stranger but you can tell how obsessed I am with airway stuff when I'm writing this on Christmas morning! Besides this is one of the few quiet moments I've had in many months to collects some thoughts before the troops wake up. I started writing you this email a while back but some how erased it and haven't gotten back to it. In any case kudos to you for keeping up the stellar podcasts. I really like how you have aligned yourselves with other outstanding minds in our field and created a more or less free forum to put out some incredible educational points for Crit Care and ER medicine.
One of my pet peeves is getting people to really understand the real benefits and proper technique of VL. I've seen and heard some of your stuff on this but I thought I'd chime in with a few of my tips and tricks that I teach on an airway course we give here in the Middle East called AIME. Originally designed and created by Adam Law an anaesthetist that hails from Canuck land. Adam has shared with me some invaluable tips in using the VL which just these subtle things can make this technique so easy anyone can do it first or second try.
One of the first things people need to understand is DL is LINE OF SIGHT. We have to have a STRAIGHT shot at the cords to be able to see and put the tube in. That's why we align the oral and laryngeal axes. And that's why we need to do the ears to sternal notch. WE CAN't SEE AROUND CORNERS WE SEE IN STRAIGHT LINES. This is what the standard straight bougie was designed to help us with. So it drives me crazy when I've heard some people talk about using a regular bougie with VL. Yes it's flexible but standard bougies don't hold a bend, they're meant to follow along the line of sight and be able to help us with those CL grade 2 and 3 views while doing DIRECT LARYNGOSCOPY (and yes I still teach that you should use it on grade I views to get the hang of it but really it's for the later). The other thing that people must understand that it isn't a “blind mans cane” for grade 4 views and shouldn't be used as such. If all you see is tongue you don't blindly kep shoving the bougie up and down hunting for clicks (sorry I know this is obvious to you but I'm just on a bit of a rant) . The last point is STANDARD BOUGIES AREN'T MEANT OR DESIGNED FOR VIDEO LARYNGOSCOPY. Ok you could argue that for a King vision or Pentax AWS a bougie is great to guide down the channel but that's not what a lot of VL's have and so a bougie is not the tool to use.
So ultimately VL is to look AROUND the corner and therefore we don't have to just “slightly” extend the neck in trauma; something we're all guilty of (just getting “that little bit more extension” to get the tube in). Alternatively someone stabilizes the neck while we do the Herculean lift to squish the tongue through the submandibular space to get our line of sight. So I think it was either Minh or Cliff who said that they really don't use VL in the field yet, I really think they need to begin to see the benefits of this.
Almost all video laryngoscope blades are much more curved than standard mac blades. WHY? AGAIN It's because they're designed to LOOK AROUND THE CORNER! The only bougie that will help you with this (if you want to use a bougie) is I think the pocket bougie from Bomimed. Now I haven't used the pocket bougie but from what I've seen on Jim Ducanto's video it can be bent or is bent to go AROUND THE CORNER. This is the only bougie that I've seen that does this. Using a STANDARD bougie may work if you're using a VL to do Direct laryngoscopy but again the blade wasn't designed to help you to see directly, the flatter, less curved mac blade was. But if you load an ETT with a properly formed stylet in almost all cases you really don't need a curved bougie with VL and especially NOT a straight bougie. I actually think we do our students a disservice by watching them do a DIRECT laryngoscopy while we watch on the Glidescope screen because the blade is so curved that the mechanics and placement of the VL blade tip in the Vallecula like you should with a regular mac blade are VERY different. Because a VL blade is so curved if you put it in the vallecula and pull in the direction of the handle like we teach with a regular mac blade, they are not pulling in the same direction as with a standard mac blade and I think that in a difficult scenario will at best won't make things easier and at worse might injure the perilaryngeal structures. People should teach DL with a standard blade NOT a VL blade. Use the right tool for the application it was designed for.
The way I teach VL is as follows.
First and foremost you must use an introducer and that introducer needs to be bent exactly in the shape of the VL blade
Because both blade and tube are so curved some times it's difficult to slide them in straight. I often tell the students to scissor their right index finger and thumb on upper and lower incisors respectively to open the mouth. Then with the blade handle pointed to 9 o clock, insert the blade. When the blade is towards the back of the tongue, rotate the handle to 12 o'clock. Now look at the screen as you slowly advance…
I agree with your “mouth, screen, mouth, screen” reminder to prevent injuries with blade and tube insertion.
I don't tell students to get the blade tip in the vallecula like with DL, it just makes VL harder because then end up pulling the larynx to anterior which just compounds the problems of passing the tube. As you and I both know seeing the cords isn't the problem, getting the tube in is. When students in their excitement of seeing that grade I view (often for the very first time!!) love to keep this view at the expense of making getting the tube in very difficult.
What I teach is a grade II view is all you need and is actually what you want. Once you get this, similar to inserting the blade you insert the tube with the long axis pointing to 3 o'clock and watch the tip go into the mouth and past the back of the tongue. Now look at the screen and keep advancing slowly. Once you can see a hint of plastic on the screen, rotate the tube to 12 o'clock and presto, the tube tip is right at the cords.
The last hold up is when they try and ram the tube and introducer in. Invariably the tube and introducer gets rammed into the anterior larynx. So the student needs to bring the tube tip to the cords and maybe just a little past. Have someone hold the introducer and continue to slide the tube off and down. If it gets hung up on the anterior larynx this is where the student can slowly twist the tube 90-180 degrees to pass the tube. Even watching Dr. Ducanto push the pocket bougie in with it's big bend he gets hung up on his video and has to do the multiple twists with the bougie to get it to pass down the trachea.
So that's my Christmas rant. I feel much better. Have a good one.
Harold, Great comments/teaching tips. I would say that we need to make a clear separation between the indirect vision video blades (Glidescope, CMAC D, etc.) and the standard/displacing blade shapes (Standard CMAC). In the latter, a standard bougie works just fine; for the former the pocket bougie seems to be the best thing out there.
let Harold and I know what you think
- EMCrit 290 – Decompensated Hypothyroidism and Myxedema with Dr. Arti Bhan - January 23, 2021
- EMCrit 289 – Ketamine Only Intubation Paper with Brian Driver - January 12, 2021
- EMCrit 288 – Neurogenic Shock & Should we be Using Vasopressors for Hemorrhagic Shock? - December 29, 2020