Video laryngoscopy in EMS
Now with ten years of history and many clinical trials behind them, video-laryngoscopes are proving to have a vital role in anesthesia
An emerging trend this year is the explosive growth of video-laryngoscopy. The buzz at last year’s ASA Conference was that in another 10 years we will all look back on the blade and handle direct laryngoscope as a primitive instrument. With a video-laryngoscope, more than one person sees the tube going between the vocal cords. It makes the difficult anterior airway easier to see, particularly when the head and neck are motion restricted.
A video-laryngoscope is as an instrument for performing endotracheal intubation, which displays the target anatomy on a screen or monitor. The first were big and cumbersome. But they now come in three different styles from small hand-held devices to those that can display on a big external screen.
In recent years we've seen many reports of problems with pre-hospital endotracheal intubation. Some EMS systems have started using more supraglottic rescue airways and fewer ET tubes. Nobody ever said a properly placed ET tube is not the definitive advanced airway. It is just that the risks were starting to outweigh the rewards. Video-laryngoscopy is one heavy new weight to drop down on these scales.
This technology promises to make intubation easier and safer, with fewer complications. It could re-focus our efforts back on what was always the gold standard of airway care. We are now seeing only the beginnings of these devices adoption by EMS providers, but they have become commonplace in hospital anesthesia departments.
Verathon makes the industry-leading Glidescope, including a pre-hospital and military version called the Ranger. You will probably find a Glidescope in the majority of large hospital anesthesia departments. They are the ones that really started video-laryngoscopy ten years ago. They were the first, and still dominate video-laryngoscopy for some good reasons.
First, the Glidescope family of products looks 60 degrees anterior, reducing the practical grade view of a difficult airway. They are also on their third production generation. As with most new technology, the guys building the best products are those with the most experiences. Verathon has experience that uniquely pertains to EMS.
With every new incarnation engineers have had the opportunity to refine and improve. The Glidescope Ranger was created with the military market in mind, resulting in a fantastic EMS product. They created the worlds first third generation video-laryngoscope in a rugged and field suitable form factor. If you have smart folks in your agency willing to learn how to use it, and if you can afford it, just buy it. It has the most proven track record, particularly on those 3 to 4 percent of endotracheal intubations that prove difficult or fail.
In the case of the Glidescope or the Truview PCD, the view displayed is one that is tilted anterior. This makes viewing the more anterior airway possible. Reducing the grade or difficulty by even one grade can mean the difference between life and death. The Glidescope has the patented feature of mounting the camera at the end of the blade at a 60-degree anterior angle.
They both see around tight corners, which has the unfortunate side effect of making the ET tube harder to place. You must use a stylet, you need good training, and you should practice. If you don’t have the time, money, or commitment to do this right, then maybe don’t do it.
Before you rule it out, I’d like to tell you about more a few more new video-laryngoscopes. We have seen the recent introduction of many new models of video-laryngoscope and improvements to older ones this last year. The new McGrath Mac is a second-generation device that was designed to be rugged in the first place. Aircraft Medical’s first version is theMcGrath Series 5 video-laryngoscope available in the USA from LMA North America.
The new McGrath Mac is less designed for rare cases; it’s more designed to make day-to-day intubation both safer and easier. It is very durably constructed and has an inexpensive disposable blade, plus I think it is one of the easiest to learn because you can see the ETT tip much earlier on the screen which makes ETT placement noticeably easier.
Karl Storz makes the C-Mac and Storz DCI Video Laryngoscopes. They recently introduced the D-Mac blade, for difficult airways. This gives them a full range of available blades combined with really outstanding image quality.
A newer low cost video laryngoscope is the CoPilot VL. This first-generation instrument has one really welcome feature, a folding blade. Ambu offers the Pentax Airway Scope, and King Systems recently introduced the new King Vision. The King Vision is the only video device that can function both as a tube introducer and as a left-hand/right-hand video-laryngoscope. It features a reusable screen and disposable blades.
Some of the video devices use a more traditional blade and handle with screen approach. The advantage of this style is the basic mechanics. You hold the video-laryngoscope in your left hand and place the tube with your right, just like traditional laryngoscopy. Using an old and well-developed motor skill is always easier than learning a new one. Others have a J-shaped insertion member with screen at the top, which into which you load a lubricated ETT.
The J-shaped devices all in some measure great or small, owe their design success to the Augustine Guide. The Augustine Guide was the first device to demonstrate that, on most normal airways, this style of tube delivery system can work very well. The Augustine Guide was invented by the same brilliant anesthesiologist — Scott Augustine — who invented the world’s best known patient warming system the Bair Hugger.
The Airtraq was the first of this type device to really achieve widespread popularity in EMS. It is a low cost optical device that is both disposable and available in a full range of patient sizes. It is another of the easiest to learn how to use and they now have a video option for it too. The other two J-shaped video introducers are the Pentax Airway Scope (AWS) and the Res-Q Scope.
The key to using this style device is to keep the vertical member vertical. Don’t tilt the top of the device back or forward. Lift up and push forward towards the patients’ feet to open the epiglottis. The third type of video intubation device is the video-stylet, an intubation stylet with a built in camera and screen. One excellent example is the Clarus Video System. Another is the Video RIFL, which has a movable distal tip.
Now with ten years of history and many clinical trials behind them, video-laryngoscopes are proving to have a vital role in anesthesia. As cost comes down and quality and durability go up, they are quickly becoming viable for EMS. Frankly, a few of them already are quite viable. They can help make the difficult airway more manageable and provide an important airway option. Today, many more progressive EMS agencies are already using them. I expect this trend to continue as video-laryngoscopes demonstrate their ability to make pre-hospital intubation safer, easier, and for the first time, witnessed.