Intubating patients can be a difficult task, and the practice can prove even more challenging in pre-hospital settings. However, video laryngoscopy has been shown to improve intubation success and is becoming more commonly used.

 

Laryngoscope-McGrath-EMS-320Paramedics face traumatic situations every day that demand quick action, excellent medical skills, and top-notch training to prevent or reduce the risk of serious injury and/or death. When it comes to intubation, the importance of having access to a device that is portable, durable, and efficient, as well as thorough training, could mean the difference between life and death. In 1993, the American Society of Anesthesiologists (ASA) formed the Difficult Airway Task Force and published its first guidelines to facilitate management of the difficult airway and reduce the risk of adverse effects. Ten years later the guidelines were modified, and in 2013 revisions recommended the use of video laryngoscopy.

Tom McGrail, director, clinical services at Ambu, pointed out that while video laryngoscopy translates well to the respiratory therapy environment, emergency personnel have little experience with the tool. “Paramedics don’t intubate every day like anesthesiologists—who have a variety of training available—do,” he said. “[Paramedics] are likely to be called on to intubate the most severely ill patients. You could call them the worst-case scenarios.”

Practice Makes Perfect

McGrail reported that paramedics in the United States, on average, do one intubation a year. “So how do they get experience? It becomes even more important to get them experience in the operating room or emergency room. But this is becoming more difficult due to rules about having [additional] people in the OR. This is creating a bigger chasm between experienced and nonexperienced paramedics,” he said.

So while training on video laryngoscopy is key, a person’s hand-eye coordination may determine how steep a learning curve will be. “If a person is good with a joystick or excels at CAD drawing, he or she might not have a problem,” McGrail said. Given this situation, some emergency systems and departments recognize the need to address proper training and are taking steps to ensure its personnel are thoroughly prepared.

Take the Montgomery County Hospital District (MCHD) and Cypress Creek EMS (CCEMS) in Texas for instance. Together these entities conducted a study1 on video laryngoscopy using the King Vision video laryngoscope and six Levitan airway training manikins with different anatomies to reflect real live patients.

Jared L. Cosper, BS, Lic-P, director–EMS, MCHD, and one of the study authors, noted that insufficient volume of intubations, rather than training, prevented staff from becoming proficient with laryngoscopy. “Our former medical director worked in a collaborative manner to develop training content with neighboring agencies and the sponsoring agencies, Southeast Texas Regional Advisory Council and Baylor College of Medicine,” he said. “We focused on both traditional direct laryngoscopy as well as video laryngoscopy using the King Vision device, formal classroom training and frequent training through field supervision.”

MCHD considered two options they felt were suitable for the challenging EMS environment and ultimately chose King Vision because the device had a good camera, reasonable initial deployment and ongoing costs, according to Cosper.  “Also, at the time MCHD deployed video laryngoscopy, the options were quite limited, and King systems had an established reputation,” he said. “Our staff felt that while the other device we considered offered a more traditional laryngoscopy technique, the King Vision device offered the best anatomical view.”

Cosper noted that MCHD employees formally practiced the procedure daily for the better part of a year using the best carbon fiber manikins on the market. “They were well prepared but, as always, any skill on a live patient is different from training,” he said. “I believe, despite our training, our staff had a slight learning curve the first time they used the device on a live patient, to which they quickly adjusted and gained comfort with the skill.”

In the last 20 months, since completing the study, MCHD has used video laryngoscopy 450 times, according to Cosper.

A Better View

McGrail explained that the King Vision features a hyperangulated blade, which allows the user to see anatomy you can’t visualize with a regular-shaped blade. “The challenge with direct laryngoscopy is that you can’t see the airway. The advantage of video laryngoscopy, even if it’s just the blade, is that it allows others in the room to see. The key is a better view.”

Additionally, King Vision’s channeled and standard disposable blades offer options for the user. McGrail noted that the first type directs the placement of the blade while the second requires a stylet for tube delivery. He pointed out that a regular shaped blade does not have a channel and cannot “look around the corner.”

Regardless of which laryngoscope a paramedic uses, blood and secretions often obstruct the view. “This is the Achilles heel of video laryngoscopy,” said McGrail. “Regular video laryngoscopy backup suggests having suction for every intubation.” With a channeled blade in the left hand, the paramedic can suction before and during the procedure with the right hand. “The disadvantage is that the channeled blade takes up more space and the mouth opening is limited. Still, when you advance the tube into position and get the blade in, it’s widely preferred by EMS,” he added. Furthermore, the anti-fog coating on the distal lens of the camera wicks away secretions to help keep a better view.

Video laryngoscopy also edges out direct laryngoscopy when it comes to positioning. Users of the latter tool prefer patients situated on a table, but the former can be used on the ground since the device allows the user to “look around the corner,” according to McGrail. “You don’t have to flex the patient’s head or put the patient in a ‘correct’ position.”

Improved Success Rates

Jeff Jarvis, MD, EMS medical director for Williamson County and Marble Falls Area EMS in Central Texas, conducted a study2 that analyzed success per attempt, overall success, first-pass success and performed an intention-to-treat analysis to account for protocol violations before direct laryngoscopy and after implementing training with video laryngoscopy. A total of 514 patients with cardiac arrest and other medical issues, but no difference in age, weight, gender or percentage receiving paralytic medications, comprised the direct and the video laryngoscopy groups. Improvements were noted in all measures in the video laryngoscopy group: overall success (64.9% vs. 91.5%, p < 0.01); first-pass success (43.8% vs. 74.2%, p< 0.01); and success per attempt (44.4% vs. 71.2%, p < 0.01).

Jarvis also produced a training video to help EMS systems with historically low intubation success rates in which he emphasizes that the psychomotor skills used for direct laryngoscopy differ from those used for video laryngoscopy. In the video he demonstrated how to hold the device—at the base where the channel joins the blade—unlike the higher grip used for direct laryngoscopy.

Video laryngoscopy has been around for nearly 15 years, dating back to 2001 when Verathon introduced the GlideScope product line; five years later the company acquired Saturn Biomedical Systems and the GlideScope video laryngoscope brand.

Early clinical trials demonstrated the GlideScope’s ability to provide a superior glottic view when compared with direct laryngoscopy. A 2005 study3 collected data regarding patient demographics and airway characteristics from 728 patients at five Canadian health centers. Both direct laryngoscopy and video laryngoscopy were performed in 133 patients. Findings revealed excellent (C/L 1) or good (C/L 2) laryngeal exposure in 92% and 7% of patients, respectively.

Thirty-five patients had a C/L grade 3 or 4 view with direct laryngoscopy, which improved to a C/L 1 view in 24 patients and a C/L 2 view in three patients. GlideScope achieved successful intubation in 96.3% of patients and provided a comparable or superior view in all cases.

During the last 10 years, GlideScope has added video laryngoscopes for preterm patients and small children to its portfolio and created advanced systems that improve real-time airway views facilitating quicker intubation. Specifically for military and EMS settings, GlideScope created the Ranger, a portable video laryngoscope built to withstand the rigors of extreme field conditions. With blade angulation, a non-glare monitor and anti-fogging mechanism, the Ranger has been awarded US Army “Airworthiness” and US Air Force “Safe-to-Fly” Certifications.

Video and Hands-on Training

Another video laryngoscope that has yielded positive results is the Clarus Video System (CVS), a video-assisted semi-rigid fiberoptic stylet. Researchers from SUNY Upstate Medical University in Syracuse and SUNY University at Buffalo conducted a study4 that evaluated the ability of advanced life support (ALS) EMTs to successfully intubate a simulated airway with this system.

Volunteer ALS EMTs watched an eight minute, 22 second video followed by a 10-minute hands-on familiarization period during which the volunteers practiced on a Laerdal Airway Management Trainer manikin situated on the floor to mimic a prehospital scenario. The participants had three attempts with both the CVS and direct laryngoscopy, which were timed from picking up the device to the removal of the stylet from the endotracheal tube. Upon successfully completing the process with one method, the volunteer then attempted the other.

Eighty-one ALS EMTs had a success rate of 95.1% in placing the ETT on the first attempt with direct laryngoscopy and 96.3% with CVS. Median times for total attempts were 15.00 seconds and 14.50 seconds for direct laryngoscopy and CVS, respectively.

Field studies have also shown video laryngoscopy effective in tactical situations. A 2014 study5 evaluated the use of video and optical laryngoscopy in a simulated tactical setting, ie, auditory and visual immersion with intubations taking place on the ground and paramedics in full tactical gear. Seven experienced tactical paramedics used each of the laryngoscopes after a one-hour training session on each of four different airway manikins for a total of 84 intubations.

Findings showed the optical and video laryngoscopes had significantly better Cormack-Lehane grades with similar times to ventilation and first-pass success when compared to direct laryngoscopy. Although video laryngoscopy has numerous benefits, no one tool works well under all circumstances, McGrail pointed out. “You have to keep direct laryngoscopy around.” RT


 

Phyllis Hanlon is a contributing writer to RT. For further information, contact [email protected]


 

Reference:

  1. Escott MEA, Gleisberg GR, Gillum LS, et al. “Deploying the video laryngoscope into a ground EMS system.” Jems 2014; 34-39. doi: http://www.jems.com/articles/print/volume-39/issue-8/patient-care/deploying-video-laryngoscope-ground-ems.html

  2. Jarvis JL, McClure SF, Johns D. “EMS intubation improves with King Vision video laryngoscopy.” Prehosp Emerg Care. 2015 Oct-Dec;19(4):482-9. doi.10.3109/10903127.2015.1005259. Epub 2015 Apr 24.

  3. Cooper RM, Pacey JA, Bishop MJ, McCluskey SA. “Early clinical experience with a new videolaryngoscope (GlideScope) in 728 patients.” CanJ. Anaesth. 2005. Feb; 52(2):191-8.

  4. Cooney DR, Beaudette C, Clemency BM et al. “Endotracheal intubation with a video-assisted semi-rigid fiberoptic stylet by prehospital providers.” Int J Emerg Med. 2014; 7(1):45. doi: 10.1186/s12245-014-0045-0. eCollection 2014.

  5. Yun BJ, Brown CA 3rd, Grazioso CJ, Pozner CN, Raja AS. “Comparison of video, optical and direct laryngoscopy by experienced tactical paramedics.” Prehosp Emerg Care. 2014 Jul-Sep; 18(3):442-5. doi. 10.3109/10903127.2013.864356. EPub 2014 Jan 24.