Editor鈥檚 note: This series of articles profiles the inventors of three innovative emergency medical care devices offered by Pulmodyne, an Intersurgical Company.
While it鈥檚 long been the prehospital standard for airway control, endotracheal intubation is one of the more challenging skills in the EMS repertoire. Done in the field, it has higher complication and failure rates than in the hospital.1 Various reasons go into that, including characteristics of patients (e.g., mouth trauma, difficult anatomy), providers (experience, comfort) and scenes (suboptimal locations and conditions). A 2014 review of data from 40 states revealed an overall out-of-hospital ETI success rate of 85.3%.2
Even with straightforward airways, getting the tube down the throat requires some assistance. Historically, that鈥檚 been achieved with a stylet 鈥� a malleable metal rod placed inside the endotracheal tube to help guide it down the trachea. Harder intubations often call for a bougie 鈥� a thin plastic rod inserted into the trachea, smaller in diameter than the stylet, over which the tube is passed. Data over the last decade has suggested that bougies may produce more successful first attempts (though a randomized clinical trial published in 2021 didn鈥檛 find a difference), and experts have begun warming to their routine use.3
Whatever your selection, it鈥檚 important to be quick and accurate in getting the introduction device and tube placed 鈥� it鈥檚 a vital temporizing measure for patients in dire states.
鈥淢ost of what we do in emergency care is stabilizing and passing off,鈥� said prominent emergency physician Richard Levitan, M.D., who has invented several key devices to benefit EMS and hospital airway management. 鈥淲hen you push drugs, people stop breathing, and you have to secure the airway. It鈥檚 one of the few times in emergency care where you鈥檙e fully responsible for the patient by an act of commission. If you mismanage the airway, there鈥檚 no passing it off 鈥� you鈥檙e going to have a dead or brain-injured patient.鈥�
Those are high stakes when you鈥檙e trying to steer a flexible tube into a glottic opening that can be hard to see and reach. The (USB), invented by Levitan and designed and developed by , is now available, helping EMS providers find their target while potentially increasing first-pass success rates.
EXPERIENCE PAVES THE WAY
A career鈥檚 worth of experience in emergency care and airway management paved the way for the USB鈥檚 invention.
Before he became part of the first class of emergency medicine residents at New York鈥檚 Bellevue Hospital in the early 1990s, Levitan discovered emergency services. He鈥檇 dropped out of college after a year and hitchhiked to Idaho, where he ended up fighting wildfires. He had an opportunity to be a wilderness ranger, but to do this he needed first aid training that he couldn鈥檛 obtain in Idaho. Instead Levitan returned to New England and became an EMT, then a paramedic. 鈥淭hat summer I worked New York City EMS and fell in love with EMS,鈥� he recalled. 鈥淚 decided instead of being a forest ranger, I wanted to be an ER doc.鈥�
He went to medical school, then on to Bellevue. By the end of his residency, he was taking anesthesia rotations and preparing a move to Johns Hopkins to pursue double-boarding 鈥� but life intervened. The untimely death of someone close interrupted the plan. But that same week, Levitan had the idea for what would become his best-known creation, the Airway Cam direct laryngoscopy video system.
Airway Cam took several years to bring to reality, but once it hit the market, it let Levitan start delivering video-based lectures and education using the device. However, the need for subjects left him a bit hamstrung. 鈥淵ou can鈥檛 do repetitive laryngoscopy three times on the same patient just for research,鈥� Levitan noted. The answer to that problem was cadavers, obtained through an anatomic gift program in Maryland.
For the next two decades-plus he ran multiple courses each year, and gradually these came to the attention of device manufacturers. They had products and product ideas, and he had the capacity to test them on manikins and cadavers, rather than live humans.
Levitan鈥檚 creations during this period included intubation training manikins for teaching laryngoscopy, as well as an anatomically correct surgical trainer, plus the Levitan FPS optical stylet, the (available from , which was recently acquired by ), and the .
The latter happened through a bit of a happy accident.
ONGOING CHALLENGES PROMPT A SOLUTION
The Airway Cam was a helpful innovation, but it didn鈥檛 resolve the issue of the tube blocking the intubator鈥檚 line of sight during laryngoscopy. As a countermeasure Levitan taught straight-to-cuff stylet shaping, which inserts the stylet straight, rather than curved (so it remains below the line of sight), with a bend of no more than 35 degrees, just beyond the proximal end of the tube cuff.
To better control bougies he conceived what is called the 鈥渟haka grip.鈥� A reference to the extended thumb and pinky gesture associated with surfers, the grip was a way to fold the bougie over, hold it with the middle three fingers and direct it while controlling which way the tip was pointed.
These were successful modifications, but Levitan wanted a more definitive solution to these ongoing challenges.
鈥淲ith my understanding of stylet shaping and some of the optics involved with that and my efforts trying to improve bougie handling,鈥� Levitan recalled, 鈥渋t occurred to me I could develop a better bougie that could work as a stylet.鈥�
He began experimenting, adding aluminum tape to the ends of bougies to help control their shape. The result could functionally work as a stylet, and he could shape it enough to work with hyperangulated video laryngoscopes. The concept for the USB was emerging.
A second epiphany completed the process: Levitan added a second metal section in the middle of the bougie. That concentrated the device鈥檚 movement within the flexible section between the metal in the middle and the metal at the tip. 鈥淭he movement between the two sections would be amplified,鈥� he explained, 鈥渁nd the effect of that mechanically would be to make the tip bouncier as it interacted with the tracheal rings.鈥�
That鈥檚 where the shaka grip comes in: Because the tracheal rings only cover the anterior two-thirds of the trachea 鈥� the back wall is flat 鈥� the bougie tip must remain oriented toward the tracheal rings and can鈥檛 rotate. The shaka grip helps prevent inadvertent rotation of the bougie inside the tube.
鈥淎 lot of bougie enthusiasts will say, 鈥極h, I can feel the rings 9 out of 10 times,鈥欌�� said Levitan. 鈥淏ut it鈥檚 often not clear that you鈥檙e feeling the rings. And the reason is, you don鈥檛 know which way the tip is pointing. If you鈥檙e holding a bougie that鈥檚 a cylindrical rod, it doesn鈥檛 have directional control 鈥� it easily rolls in your hand. And although there are markings on the upper side, it鈥檚 very hard to see them while you鈥檙e using the device, so you don鈥檛 really know where the tip is pointing.鈥�
Levitan molded his resulting product for inherent directionality, so when it鈥檚 held in the middle, the proximal end, pointing away from the intubator, and the distal tip are both oriented to 12 o鈥檆lock. 鈥淪o under an epiglottis-only view,鈥� Levitan added, 鈥淚 can know which way is up.鈥� He also made the USB hexagonal instead of cylindrical so, with only six points of contact rather than an entire circumference, there would be less friction along the tube, making it easier to insert and remove the device.
A final design touch involved flattening the tip of the proximal end. That lets it be tucked back over and into the proximal end of the tube to prevent accidental movement before the tube is railroaded over the USB. An ancillary benefit was that the new device could be packaged smaller 鈥� about the size of a tracheal tube 鈥� whereas traditional bougies are carried straight and thus harder to pack conveniently.
The final product met the range of anticipated needs as deftly as Levitan had imagined. It was rigid enough to function as a stylet, yet flexible enough to work as a bougie. And it would be quick and convenient in both EMS and EDs.
鈥淵ou can use this as a regular stylet, you can use it as a bougie, you can use it as a hyperangulated stylet, and you can use it as a hyperangulated bougie,鈥� he said. 鈥淭he USB replaces multiple devices, and I believe it works better as a bougie than a regular bougie, better as a stylet than a regular stylet, and better as a hyperangulated device.鈥�
AIRWAY PROVIDERS MUST BE ONE-AND-DONE
When the USB was ready for unveiling, Levitan brought it to 鈥� a manufacturer he knew could engineer it right.
鈥淲hat I鈥檝e discovered as an inventor,鈥� he said, 鈥渋s that it鈥檚 one thing to have an idea. But really, the only reason any product works is because an engineer then put their shrewd insight into how to produce it cost-effectively and efficiently. Without that, it wouldn鈥檛 work. And when I shared my idea about the USB, they instantly understood, even though it鈥檚 more complicated than a bougie, how it could be produced.鈥�
Intersurgical loved the idea and brought it to market in 2021. It鈥檚 now assisting intubators in both EMS and hospital settings in a range of cases both challenging and straightforward.
鈥淭here are a lot of uses for this device,鈥� Levitan said. 鈥淚 work in a little hospital in the middle of nowhere, and if I get called to the ICU, I鈥檓 managing that airway with no backup. I鈥檝e had cases like a 6 1/2-foot, 450-pound guy with COVID-19, where I put a laryngoscope in and could barely see the epiglottis. But even with that view, I drop the USB in, feel the tracheal rings and am like, 鈥楶hew 鈥� done!鈥�
鈥淭here are cases where the epiglottis is long and curvilinear, which we see more and more with obese people. I鈥檝e had cases where tube delivery was tight because the mouth wouldn鈥檛 open or a rigid stylet kind of hung up. You don鈥檛 have a lot of movement when you鈥檙e using a hyperangulated rigid stylet. And I鈥檝e switched to the USB, and it鈥檚 like, 鈥極h, done!鈥�
鈥淲hat鈥檚 changed over the years is that acceptable risk has gone down,鈥� he added. 鈥淎s airway providers, whether you鈥檙e an EMS medic, ER doc, ICU doc or anesthetist, we have to basically do one-and-done. We can鈥檛 risk prolonged and repetitive airway efforts because in critical patients, those are associated with bad outcomes. So like with the rest of our lives, we鈥檝e grown less accepting of risk. And that鈥檚 a good thing. Let鈥檚 make sure we鈥檙e getting this one-and-done. And the USB I think addresses that really well.鈥�
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REFERENCES
1. 鈥淓MS field intubation.鈥� David M. Gnugnoli, Abhishek Singh, Katherine Shafer. StatPearls [Internet]. 2023. www.ncbi.nlm.nih.gov/books/NBK538221/
2. 鈥淎n update on out-of-hospital airway management practices in the United States.鈥� Leigh Ann Diggs, Juita-Elena Wie Yusuf, Gianluca De Leo. Resuscitation. July 2014. https://pubmed.ncbi.nlm.nih.gov/24642405/
3. 鈥淓ffect of use of a bougie vs endotracheal tube with stylet on successful intubation on the first attempt among critically ill patients undergoing tracheal intubation: A randomized clinical trial.鈥� Brian E. Driver, Matthew W. Semler, Wesley H. Self, et al. JAMA. 2021. https://jamanetwork.com/journals/jama/fullarticle/2787158
