A Rant on Video Laryngoscopy

Got this email from a listener:

Hi Scott

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.

Cheers

Harold Shim

My Comments:

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.

Your Comments…

let Harold and I know what you think

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Comments

  1. Minh Le Cong says:

    Hi Harold and Scott!
    what a rant! great stuff!
    Having used king Vision VL last week on a trauma airway that was Grade 4 CL on DL but 3 with VL, I agree that VL has a role in prehospital airway management!
    I have tested the Ranger Glidescope for a month now. it has not been met with wild enthusiasm by myself and colleagues mainly because of some of the key points you raise here. Hypercurved indirect bladed VL systems require a distinct technique in both tube delivery and passage.

    I totally agree with you on standard bougies and VL systems like GLidescope. The Pocket bougie is different as it holds quite a curve and seems to work well with devices with similar curve blade.

    ultimately I agree with Levitans view on this. the future standard will be DL and VL combined device. it will be cheap and disposable. you will have it ready in your difficult airway kit or trolley. or it will be so cheap you can use it on every intubation if you choose. It will have wireless transmission of the VL image to either the internet cloud bAsed system or locally via bluetooth to your iphone. ipad or windows tablet. future patient monitors , USS displays will be able to connect to the VL tranmission or locally via bluetooth or USB cable,
    This device will be multipurpose to enable ENT exams, laryngeal examinations much easier.
    there will be ETT with cameras on tip, wireless transmission, fully disposable. these already exist but the cost will come down and wireless and independent battery function will be added. You will have an ETT with a small battery pack and transmitter on the proximal part, fully self contained with bluetooth and wifi transmission to any enabled device.

    In other words, the move will be away from specific design VL systems towards ubiquitous image transmission and connectitvity to solve the monitor / display issues of current systems. Cheaper disposable formats will solve the issues of expensive systems.

    this will make awake intubation techniques and airway exams much more reliable and practical within realm of the EM doctor. RSI in fact will become less relied upon as the main method of airway securing.

    thats my prediction. maybe it does not all happen in 2013… but I know some of it will!

  2. Minh Le Cong says:

    http://www.ncbi.nlm.nih.gov/pubmed/23231426

    check out article above on VL vs DL in critical care transport service.

  3. I’ve used the bougie with virtually no view of anything but the tongue on dozens of patients with 100% success.

    I find that finding my external landmarks manually with my left hand before I insert the scope, having an assistant then place and hold their fingers exactly where I had them gives me a target and from then it’s pretty easy stuff.

    I will admit that in the first days of the bougie, it took a couple of attempts a couple of times and I had to abort and re-oxygenate a couple of times as well. But now that I’ve used the device so much, and we have refined our techniques for preparation for intubation, that I haven’t had even a hiccup. And this is especially useful for the immobilized trauma patient.

    I am happy that the technology is improving in VL, but I still don’t see a day when it will be easier or faster for me than my Mac 4 and a bougie.

  4. I currently use a McGrath Mac in prehospital (HEMS and ambulance) setting. The Mac has a standard (Macintosh) blade and works really fine with the standard Bougie (just applying a little bend). My tip when I teach VL is: stay a little back with the blade, don’t load the epiglottis, visualize the cords (CL 2 ) so the glottic plan is lower and it’s easier passing the tube (golf stick shaped)

  5. Ryan Z. says:

    At my fire based gorund service, we have a GlideScope that is our first line equipment. Initially it was a little bit awkward to use with the rigid stylettes, but, with a bit of practice and use on live patients, the bulk of our paramedics have gotten used to it, and can use it without difficulty. I recently was forced to use a standard handle, and mac blade on a cardiac arrest with another service I work for, and it was by far, one of the hardest intubations I’ve done since paramedic school. Not because the view was bad, or due to vomit, or anything else, but to just poor muscle memory and skill degradation with a standard handle/blade combo.

    In my eyes, if you aren’t using VL in daily practice for airway management, you are well behind the times, and are causing more harm than good. Having worked in an urban hospital, it’s scary to see some of the airway grades, and see the doc pick up a standard handle when a VL is available on the otherside of the bed…

  6. Talking of video devices. What do you guys think of this one?
    http://arasan.us/VuStik_Video-Stylet.html
    This would involve no change in our usual technique. I like the look of the little light weight screen better than the videostylets with eyepieces, or one device I have seen with a bulkier looking screen.
    And of course we can still use our usual laryngoscopes.
    But I can’t find out much about it online, perhaps because it hasn’t been out long. Have any of you tried this one?

  7. John Hinds says:

    Our prehospital teams 5 year success rate at intubation using DL and bougie is 100%.
    Highest reported success in randomised prehospital trial for VL is less than 50 %.

    Currently, I’d consider it unethical for us to change our practice to using VL as first choice technique!

    -John

    • Hi John,

      I definitely applaud your success rate with DL and the bougie and if that’s what you guys are good at it stick with it. Again my rant was to do with the fact that if you use a DL technique (which you are obviously expert at) with VL (specifically glidescope and the other hyper curved VL scopes it WILL be more difficult. The technique I described for successful VL obviously is not the only trick that works but I just wanted to share this as I find many people like in your shop are having lower success rates with VL. Regardless, if you’re happy with what your doing and having good success, more power to you. H

    • Eric Rottenberg says:

      Hi John,

      I totally agree with you about using direct laryngoscopy with a bougie. The comments below including references are what I sent to Harold and Scott. So far no one has sent me any replies or feedback in response to my posted comments. I guess everyone is sold on video laryngoscopy. There are not only issues with it but also it is very expensive.
      Eric
      Hi Harold and Scott,
      I read your “video intubation rant” with great interest. Takenaka and colleagues[1] found that difficult laryngoscopy is not synonymous with difficult intubation. Laryngoscopy was difficult in 17 of the 587 patients studied; however, in only 4 patients intubation was difficult, but in the remaining 13 patients the trachea was easy to intubate. The size/area of the laryngeal aperture (LA) created during Macintosh laryngoscopy in the difficult group, which they found to be one cause of difficult intubation, was significantly smaller than that in the easy group. In contrast, the LA area provided by jaw thrust during fiberoptic-aided intubation in the difficult group was similar to that during laryngoscopy in the easy group. Hence, just because you have a grade II, III or IV view and are unable to directly see the LA/vocal cords during laryngoscopy, does not mean that you are going to have a difficult time intubating the trachea. Therefore, it seems to me that intubation during a grade II, III, or IV laryngoscopy should be done while holding a dental mirror properly positioned together with a Macintosh laryngoscope in your non-dominant hand[2, 3] and using a straight bougie in your other hand to guide intubation when the LA area seen via the dental mirror is large and using a curved bougie when the LA area is small. Thank you for you consideration of my opinion and I look forward to your comments.

      Eric
      References:
      1. Takenaka I, Aoyama K, Kadoya T, Sata T, Shigematsu A. Fibreoptic assessment of laryngeal aperture in patients with difficult laryngoscopy. Can J Anaesth. 1999 Mar;46(3):226-31.
      2. Yokoyama T, Yamashita K, Manabe M. Dental mirror is a relief for difficult endotracheal intubation. Anesth Analg. 2006 Oct;103(4):1059.
      3. Agrò F, Cataldo R, Antonelli S, Mattei A, Barzoi G. Tracheal intubation with the aid of a ‘dental mirror’. Resuscitation. 1999 Nov;42(3):247-50.

      • Full Disclosure of Conflict of Interest: I own a medical device company that manufactures and markets a video laryngoscope.

        I’d like to offer my opinion on why I believe everyone is sold on VL and why DL should be relegated to the history books.
        Science!
        We now have over a decades worth of data showing that VL is far superior to DL in terms of being able to locate the glottic opening. If you can see where you want to go, its much easier to get there and to do so without causing harm to the patient in the process.

        I personally, with all due respect, find it very hard to believe a claim of 100% intubation success over a 5 year period in the prehospital setting. That is contrary to all published literature (of which there is no shortage). Having performed over 5,000 intubations, I would consider myself pretty darn good at DL. But I can’t claim 100% success.
        Even if you are 100% successful, how many attempts is it taking and what is being done to the patient in the process? Dunfore, et al (1) found that even though 84% of the intubations were described as “Easy” by the clinician, the patients were experiencing significant hypoxia and bradycardia during intubation. The median duration of desaturation was 160 seconds. That’s 2 minutes and 40 seconds of low SPO2 in patients that had a sat of greater than 90% before the intubation attempt. These patients had significantly higher mortality and fewer good outcomes than patients in a case matched control series. An intubation that takes almost 3 minutes and causes severe physiological changes is not an “easy” intubation, is not good patient care and although you may be able to place it into the 100% success column, it should not occur. Just because it is possible to successfully place an ETT without being able to visualize the cords does not mean you should.

        In contrast, Wayne, et al (2) found that the use of VL in the prehospital setting resulted in shorter laryngoscopy times by 50%, half the number of attempts and a 97% success rate. I have never seen a study documenting only 50% success with VL.

        The reason VL is more successful is because there is a 99% chance
        you will be able to see your target; the vocal cords. This is what the literature tells us. I’m not saying VL is perfect or that injuries can’t occur. No medical procedure is without risk. But the question you have to ask yourself is, can it be safer than the old way? I have to vote Yes.

        Jay Tydlaska, CRNA

        1. Ann Emerg Med. 2003 Dec;42(6):721-8
        2. Prehospital Emergency Care Apr 2010, Vol. 14, No. 2: 278–282.

        • Eric Rottenberg says:

          Hi Jay,

          In defense of John, in the Netherlands for example, the average number of endotracheal intubations per paramedic in one year was 4.2 and varied from zero to a maximum of 12[1]. This study found that the incidence of endotracheal intubations performed by Dutch paramedics in one year was low, but endotracheal intubation was successful in 95.2%, which is comparable with findings in international literature. However, you make an important point that just because it is possible to successfully place an ETT without being able to visualize the cords does not mean you should, particularly if it takes a prolonged period to do so. But, in my defense, VL is expensive and not all paramedic services have that luxury and I brought his attention to studies that show him how to use a dental mirror with DL so he can inexpensively visualize the laryngeal aperture and/ or cords when they can’t be directly visualized and then visually guide the ETT into the trachea. I was, however, wrong about my idea of using a bougie with a dental mirror. But that’s what I get for citing these papers without reading them and then engaging in baseless creative thought about them.
          1. Wilbers NE, Hamaekers AE, Jansen J, Wijering SC, Thomas O, Wilbers-van Rens R, van Zundert AA. Prehospital airway management: A prospective case study. Acta Anaesthesiol Belg. 2011;62(1):23-31.

          • Hi Eric,

            As you point out, paramedics simply don’t get the experience that we do in the operating room. I may intubate more times in one day than many paramedics intubate in an entire year. So that is one of the main issues. The other is that paramedics have to intubate the worst airways, in the worst conditions. In the OR, we don’t have to worry so much about vomit or blood in the airway. We have plenty of light, equipment, time, help and the ability to properly position the patient. The odds are not stacked in their favor. That’s why we have more success and less complications in the OR. But still, even with all our experience and optimum conditions, we do not have 100% success and patient are injured and do die because of the limitations of DL. We have 7 decades of data showing that. So no matter how much we would like it to be true, no EMS system has 100% success with DL and certainly not without serious complications.

            Now I am not advocating that everyone immediately stop performing DL in favor of VL. Even though I believe that would result in the best patient care that is currently possible when intubation is required, thats simply not reasonable because of cost constraints. Financial limitations are a definite barrier to entry. Not only is this a major concern for underfunded EMS systems, but most hospitals could not even consider a complete conversion to VL with what is currently available. Some hospitals and EMS systems are able to convert to VL for all their intubations, but most do not currently have that luxury yet.

            I do agree that success rates in the 90% – 95% are absolutely achievable in the prehospital environment; even higher. We have the data to prove it. But I believe those numbers are best case and that those success rates come with some unacceptable complications.

            Not having the funding to purchase VL devices is a perfectly acceptable reason for not making the switch. Claiming that DL works just fine is not.

            Jay Tydlaska, CRNA
            Full Disclosure of Conflict of Interest: I own a medical device company that manufactures and markets a video laryngoscope.

        • DocXology says:

          These are all surrogate markers.

          The important outcome measure is whether or not harm occurs as a result of process of securing the airway with whatever device you happen to use. My understanding of the data is in locations with rapid access to a trauma centre, pre-hospital intubation has not been proven to alter outcomes.

          I’d be also interested in real world data with success rates of occasional intubators, not equipment reps with ’5000 intubations’ other their belt.

          I’d be concerned if a paramedic was allowing the patient to desaturate significantly before returning to bag-mask ventilation. As Dunfore concludes, good oxygenation and pre-oxygenation is the key, not intubation.

          ‘Superior judgment beats superior skill….. beats superior equipment”

          • Eric Rottenberg says:

            Hi Docxology,

            Below are the comments I sent in response to the emcrit January 16, 2013 at 17:31 comments “Jay, this whole set of comments have been truly excellent”. My most important point is no matter what airway management skills are taught to Paramedics and EMTs (including manual airway control techniques, the use of alternate airway devices and devices used in endotracheal intubation) they are often going to do a poor job of managing the airway because they aquire, hone, and maintain all their skills with only manikin practice. As I evidenced in my comments this is highly ineffective and all the practice in the world is not going to improve their skills. Moreover, as I evidenced regarding a study of combitube use versus endotracheal intubation by basic EMTs, the rate of successful endotracheal intubation without ongoing practice was 63% (70 of 111 patients), which was shown to be no different than with the Combitube (62%) without ongoing practice. As I suggested, I feel the best solution to improving prehospital airway management and time to successful DL intubation, which will hopefully improve patient outcomes, is to train both EMTs and Paramedics in endotracheal intubation with the use of a dental mirror.
            Eric
            Hi Jay and Scott,
            While I respect your knowledge, experience and expert opinions regarding tracheal intubation, there are important issues that you may not be considering. As you already know, paramedics virtually get no supervised intubation training and experience in patients; they virtually rely entirely on manikin practice to acquire, hone and maintain their skills. However, Yuan and colleagues[1] in their comments on a study of VL training in manikins, cite research in which it was suggested that tracheal intubation is not reliably simulated by manikins due to the use of rigid plastic, lack of collapsible soft tissues, absence of secretions and that many manikins have anatomically incorrect epiglottic and laryngeal structures. In addition, among several criticisms and issues that they raised regarding VL intubation and training in its use, they also cited a recent review of the literature that concluded that so far, there is inconclusive evidence indicating that VL intubation should replace DL intubation in patients with normal or difficult airways. In their opinion, DL still is an essential skill of ACLS providers and every effort should be made to maintain and improve it.

            In strong support of Yuan’s et al perspective regarding VL, particularly issues that pertain to intubation training (and for that matter development of airway management skills) in manikins, which is the only training a paramedic gets, I present the following evidence. Wang et al[2] in their extensive study of out-of-hospital airway management in the United States, found that overall alternate airway insertion success was 87.2% (1521 of 2246 insertion attempts were with a Combitube). On the other hand, overall endotracheal intubation success was only 77% (6482 of 8418 patients, 90% of which was orotracheal intubation). Rumball et al[3] found the rate of successful insertion of a Combitube without ongoing manikin practice for basic EMTs was only 62% (26 of 42 patients),and even with ongoing manikin practice, success was not much better 68% (36 of 53 patients). On the other hand, they found that the rate of successful endotracheal intubation without practice was 63% (70 of 111 patients), which was no different than with the Combitube (62%), and with practice was 76% (105 of 139 patients), which was similar to the results of Wang et al. However, Rabitsch et al[4] in their comparison of endotracheal intubation versus Combitube insertion in an urban emergency medical services system run by physicians, found the success rate for intubation was 94% versus 98% for the Combitube (89% with esophageal placement and 9% endotracheal placement). As evidenced by these studies, training in manikins is highly inadequate to develop any airway management skills including VL intubation. This is most strongly evidenced by the 9% blind endotracheal intubation success rate with a combitube by these physicians; their skill development in humans is what allowed them to accomplish this. Therefore, as Yuan et al opined, DL still is an essential skill of ACLS providers and every effort should be made to maintain and improve it. As I discussed in my previous blog, use of a dental mirror is likely the best way to improve intubation success rates in paramedics and EMTs and not VL.

            References:
            1. Yuan YJ, Xue FS, Wang Q, Liu JH, Xiong J, Liao X. Comparison of the tracheal intubation using Macintosh laryngoscope and GlideScope® videolaryngoscope by advanced cardiac life support providers in a manikin study. Minerva Anestesiol. 2011 May;77(5):558-9.
            2. Wang HE, Mann NC, Mears G, Jacobson K, Yealy DM. Out-of-hospital airway management in the United States. Resuscitation. 2011 Apr;82(4):378-85.
            3. Rumball C, Macdonald D, Barber P, Wong H, Smecher C. Endotracheal intubation and esophageal tracheal Combitube insertion by regular ambulance attendants: a comparative trial. Prehosp Emerg Care. 2004 Jan-Mar;8(1):15-22.
            4. Rabitsch W, Schellongowski P, Staudinger T, Hofbauer R, Dufek V, Eder B, Raab H, Thell R, Schuster E, Frass M. Comparison of a conventional tracheal airway with the Combitube in an urban emergency medical services system run by physicians. Resuscitation. 2003 Apr;57(1):27-32.

  8. Minh Le Cong says:

    of course I agree with John Hinds!
    a new car with GPS is a handy thing to have, partic if you are heading to a strange location…but the driving technique is the same regardless of GPS.

    and when your GPS fails , yu still need to be able to read a map ..or ask for directions/help.

  9. Eric Rottenberg says:

    Hi Harold and Scott,

    I read your “video intubation rant” with great interest. Takenaka and colleagues[1] found that difficult laryngoscopy is not synonymous with difficult intubation. Laryngoscopy was difficult in 17 of the 587 patients studied; however, in only 4 patients intubation was difficult, but in the remaining 13 patients the trachea was easy to intubate. The size/area of the laryngeal aperture (LA) created during Macintosh laryngoscopy in the difficult group, which they found to be one cause of difficult intubation, was significantly smaller than that in the easy group. In contrast, the LA area provided by jaw thrust during fiberoptic-aided intubation in the difficult group was similar to that during laryngoscopy in the easy group. Hence, just because you have a grade II, III or IV view and are unable to directly see the LA/vocal cords during laryngoscopy, does not mean that you are going to have a difficult time intubating the trachea. Therefore, it seems to me that intubation during a grade II, III, or IV laryngoscopy should be done while holding a dental mirror properly positioned together with a Macintosh laryngoscope in your non-dominant hand[2, 3] and using a straight bougie in your other hand to guide intubation when the LA area seen via the dental mirror is large and using a curved bougie when the LA area is small. Thank you for you consideration of my opinion and I look forward to your comments.

    Eric
    References:
    1. Takenaka I, Aoyama K, Kadoya T, Sata T, Shigematsu A. Fibreoptic assessment of laryngeal aperture in patients with difficult laryngoscopy. Can J Anaesth. 1999 Mar;46(3):226-31.
    2. Yokoyama T, Yamashita K, Manabe M. Dental mirror is a relief for difficult endotracheal intubation. Anesth Analg. 2006 Oct;103(4):1059.
    3. Agrò F, Cataldo R, Antonelli S, Mattei A, Barzoi G. Tracheal intubation with the aid of a ‘dental mirror’. Resuscitation. 1999 Nov;42(3):247-50.

  10. Pieter Leysen says:

    let me start by saying great topic and great comments. we use the C-mac VL and on the left side of the blade is a groove. This is perfect for the introduction of a standard bougie. I do not know if there are people out there who have tested this during training sessions but for me it works every time. I’ll try to email scott pictures to make it clear what I mean.
    My apologies for the lesser english.

    • Pieter,

      We have done the same, but for our bougie, we must preload it into the blade groove before placing the blade into the mouth.

      • Pieter Leysen says:

        same here,
        I’ve tried with a second person to load the bougie and this works ok but it does require some getting used to the technique.

  11. Here is a video I made back in the fall describing the technique Pieter and Scott are referring to. Video demonstrates Pocket Bougie preloaded into channel of D Blade of Karl Storz VL system.

  12. Full Disclosure of Conflict of Interest: I own a medical device company that manufactures and markets a video laryngoscope.

    Harold and Scott,

    FANTASTIC post covering the technique needed for VL, which is truly different than the technique needed for DL. It can be frustrating to teach VL to an experienced clinician with literally thousands of intubations under their belt because too often, they tend to not listen to the instructions that will help them be successful. Instead, they try to apply the same maneuvers and techniques to VL that they use for DL and invariably end up experiencing failure. Even though the tools are similar and the desired outcome is the same, there really is a difference in the technique required to be successful at VL. And Harold, you hit the nail on the head with your suggestions. The first thing that new VL users will want to do is insert the scope too deeply, even when that is that last thing you tell them NOT to do immediately before they attempt intubation. They are subconsciously seeking the Holy Grail that is the Grade 1 view. But as you pointed out, by doing so, they end up pushing the entire larynx anterior which makes the actual intubation much more difficult despite having a perfect view of the cords. The point that we try to drive home is that a grade 2 view is always preferable to a grade 1 view. We instruct clinicians to have the epiglottis visible on the display; even slightly obstructing the anterior portion of the cords. By doing this, the entrance to the glottis will remain in a more neutral plane and will be easier to enter with the ETT.
    The use of the stylet, which is necessary for most VL devices, is the next problem we have to tackle. The clinician will typically insert the styleted tube too deeply before attempting to turn it to enter the glottis. The technique that we teach is identical to yours but we have given it a name that seems sink in a lot quicker. We call it the “Fish Hook, Slot Machine” technique. We tell the clinician that after rotating to the 12 o’clock position, they want to just barely see the tip of the ETT on the screen. At that point, they should move their hand to the top of the styleted ETT and perform the slot machine portion of the maneuver so that the curve of the ETT is rotated around the tongue and will be directed right where it needs to go.
    Inevitably, users of VL will eventually feel the urge to reach for a bougie due to a problem that seems to haunt almost all VL devices; that is, you can see the cords perfectly, but you can’t get the tube to go there. This problem exists as a side effect of what makes VL so superior to DL; it sees around the corner. The problem arises when you can’t navigate your ETT around the corner as easily as the scope. I experienced this problem first hand when I began using VL about 5 years ago. To me, the solution was not just using the bougie but developing a device that WAS designed to work hand in hand with a bougie. So we incorporated a “Bougie Port” into our device that allows for the bougie to be used as an intended part of the intubation, not just an after thought.
    Despite my considerable experience with DL, it only took a single can’t intubate, can’t ventilate scenario that was rescued thanks to VL, to change my entire outlook on airway management. We now have over 10 years of data pointing to the superiority of VL in terms of being able to view the glottis. For me personally, VL will always be my first choice when it comes to intubation for the remainder of my career.
    Now if I just had a nickel for every time I’ve been asked for a straight blade with a camera, I’d be rich.

    Jay Tydlaska, CRNA

    • Jay, this whole set of comments have been truly excellent

      • Eric Rottenberg says:

        Hi Jay and Scott,
        While I respect your knowledge, experience and expert opinions regarding tracheal intubation, there are important issues that you may not be considering. As you already know, paramedics virtually get no supervised intubation training and experience in patients; they virtually rely entirely on manikin practice to acquire, hone and maintain their skills. However, Yuan and colleagues[1] in their comments on a study of VL training in manikins, cite research in which it was suggested that tracheal intubation is not reliably simulated by manikins due to the use of rigid plastic, lack of collapsible soft tissues, absence of secretions and that many manikins have anatomically incorrect epiglottic and laryngeal structures. In addition, among several criticisms and issues that they raised regarding VL intubation and training in its use, they also cited a recent review of the literature that concluded that so far, there is inconclusive evidence indicating that VL intubation should replace DL intubation in patients with normal or difficult airways. In their opinion, DL still is an essential skill of ACLS providers and every effort should be made to maintain and improve it.

        In strong support of Yuan’s et al perspective regarding VL, particularly issues that pertain to intubation training (and for that matter development of airway management skills) in manikins, which is the only training a paramedic gets, I present the following evidence. Wang et al[2] in their extensive study of out-of-hospital airway management in the United States, found that overall alternate airway insertion success was 87.2% (1521 of 2246 insertion attempts were with a Combitube). On the other hand, overall endotracheal intubation success was only 77% (6482 of 8418 patients, 90% of which was orotracheal intubation). Rumball et al[3] found the rate of successful insertion of a Combitube without ongoing manikin practice for basic EMTs was only 62% (26 of 42 patients),and even with ongoing manikin practice, success was not much better 68% (36 of 53 patients). On the other hand, they found that the rate of successful endotracheal intubation without practice was 63% (70 of 111 patients), which was no different than with the Combitube (62%), and with practice was 76% (105 of 139 patients), which was similar to the results of Wang et al. However, Rabitsch et al in their comparison of endotracheal intubation versus Combitube insertion in an urban emergency medical services system run by physicians, found the success rate for intubation was 94% versus 98% for the Combitube (89% with esophageal placement and 9% endotracheal placement). As evidenced by these studies, training in manikins is highly inadequate to develop any airway management skills including VL intubation. This is most strongly evidenced by the 9% blind endotracheal intubation success rate with a combitube by these physicians; their skill development in humans is what allowed them to accomplish this. Therefore, as Yuan et al opined, DL still is an essential skill of ACLS providers and every effort should be made to maintain and improve it. As I discussed in my previous blog, use of a dental mirror is likely the best way to improve intubation success rates in paramedics and EMTs and not VL.

        References:
        1. Yuan YJ, Xue FS, Wang Q, Liu JH, Xiong J, Liao X. Comparison of the tracheal intubation using Macintosh laryngoscope and GlideScope® videolaryngoscope by advanced cardiac life support providers in a manikin study. Minerva Anestesiol. 2011 May;77(5):558-9.
        2. Wang HE, Mann NC, Mears G, Jacobson K, Yealy DM. Out-of-hospital airway management in the United States. Resuscitation. 2011 Apr;82(4):378-85.
        3. Rumball C, Macdonald D, Barber P, Wong H, Smecher C. Endotracheal intubation and esophageal tracheal Combitube insertion by regular ambulance attendants: a comparative trial. Prehosp Emerg Care. 2004 Jan-Mar;8(1):15-22.
        4. Rabitsch W, Schellongowski P, Staudinger T, Hofbauer R, Dufek V, Eder B, Raab H, Thell R, Schuster E, Frass M. Comparison of a conventional tracheal airway with the Combitube in an urban emergency medical services system run by physicians. Resuscitation. 2003 Apr;57(1):27-32.

  13. I am a sales rep and have a question. If EMT’s are trained DL with traditional blades, would you be more comfortable using a VL system that has traditional blades so you do not have to learn a new technique and will not lose your “muscle memory”? Also, I am seeing more EMS and Air Rescue services utilizing image capture of tube placement for documentation, then attaching the image to the patient chart. Is this feature a huge benefit, or becoming popular?

    Nate

  14. It seems most agree that VL gives a better view but is quite expensive compared to DL so possibly can’t replace it for routine & difficult intubations? If the argument is purely on whether its economical, then a MAC-type standard blade VL with an inexpensive video camera incorporated would be the answer? I wonder why manufacturers can’t go ahead and just create them, the technology to do so exists today. The setup here (albeit proof-of concept stuff) cost me around 40$ US http://link.springer.com/article/10.1007/s10877-013-9522-x

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