It’s been a common lament throughout the brief history of American EMS: Many of the prehospital interventions performed by EMTs and paramedics, though well-intended and blessed by medical directors, just aren’t based on strong evidence. That’s probably not too surprising for a specialty that’s only been around since the 1970s within a larger field that’s changing swiftly, but it’s certainly suboptimal for patients.
The Institute of Medicine summed up the problem in its landmark 2007 “Emergency Medical Services: At the Crossroads” report: “The evidence base for many practices routinely used in EMS is limited. Strategies for EMS have often been adapted from settings that differ substantially from the prehospital environment; consequently, their value in the field is questionable, and some may even be harmful.”1
The good news is that’s changing. With the recent emphasis on evidence-based medicine, the industry’s leaders and academics have substantially bulked up the scientific bases supporting many common practices. One of those is laryngoscopy. There’s now much important literature around this essential intervention that providers who want to do their best for patients should know.
“We’re at the point now where the information is robust, and there’s so much research out there,” said Patrick Shay, a certified registered nurse anesthetist from Pennsylvania, paramedic since 1988 and EMS educator who lectures frequently on airway management. “From both EMS and the ER and even the OR, we have some really great studies to guide us.”
Those studies depict a surprisingly clear picture about what best serves patients who require laryngoscopy.
WHAT DOES IT SAY?
In a 2023 EMS World Expo presentation on increasing first-pass success, Shay – who serves as lead instructor for the Harrisburg Area Community College paramedic and prehospital RN programs – cited several key pieces of research:
- A retrospective study from 2015 sought to clarify conflicting earlier findings around video vs. direct laryngoscopy by paramedics.2 Authors led by prominent EMS physician Jeff Jarvis looked at patient care reports from a suburban system with low historical intubation success rates and evaluated several metrics before and after the addition of video laryngoscopy (VL) using a common device. The move from direct to video laryngoscopy yielded improvements in overall intubation success (64.9% to 91.5%), first-pass success (43.8% to 74.2%) and success per attempt (44.4% vs. 71.2%). Subgroup analysis showed improvement in all metrics for all intubation indications.
- A 2017 German study tested video laryngoscopy against direct for inexperienced providers training on manikins.3 Participants attended a hands-on workshop where they learned both methods, then simulated endotracheal intubation of several normal and difficult airways. Among 22 participants (primarily trauma surgeons), video laryngoscopy produced better Cormack-Lehane view grades and visibility of the glottis and contributed to faster intubation times. “The hyperangulated blade geometries of video laryngoscopes provided a better visibility in difficult airways than the standard geometry of the Macintosh-type blade,” the authors noted. “After a short introduction and hands-on training, a video laryngoscope seems to be safe and usable by unexperienced providers.”
- A 2019 retrospective review of first-pass intubation success by ambulance personnel in Wisconsin using video versus direct laryngoscopy found a 12.6% higher rate using video.4 “This is promising,” authors noted, “because decreasing failure rates provide better patient outcomes.”
These opening pieces of literature depicted a clear theme: For prehospital providers and those with limited intubation experience, video laryngoscopy appears to improve both first-pass and overall intubation success and contribute to better outcomes.
“Those were three big studies that basically found, among providers with not-so-great first-pass success, you can introduce video laryngoscopy and quickly be doing much, much better,” said Shay.
First-pass success is extremely important, and other literature shows why.
Most recently, an analysis of emergency department data from a large national registry examined the relationship between intubation complications and numbers of attempts among patients undergoing emergency intubation.5 Reviewing more than 15,000 cases, those authors found odds ratios for major complications compared to first-pass success were 4.4 for two attempts, 7.4 for three and 13.9 for four – a precipitous rise in risk.
That picture was already emerging a decade earlier when Arizona investigators looked at the importance of first-pass success in the ED.6 Among 1,800 intubations, they found an adverse event (AE) rate of 14.2% with successful first attempts, which rose to 47.2% with two attempts, 63.6% with three and 70.6% with four or more. Noted those authors, “More than one attempt at tracheal intubation was a significant predictor of one or more AEs.”
Last year other authors from the U.K., discussing findings from a pair of earlier projects, noted “first-pass success is associated with fewer complications in both the ICU and emergency department” and that complications were linked to poorer outcomes.7 The investigations they reviewed – the INTUBE study8 and DEVICE trial9 – both found improved first-pass success with a video approach, with rates improving from 79.1% with DL to 83.8% with VL in the first and 70.8% to 85.1% in the second. “These studies,” the U.K. researchers concluded, “support the assertion that video laryngoscopes should be used in both the emergency department and ICU.”
WHAT DEVICES WORK BEST?
With video laryngoscopy appearing a preferable approach across settings, additional investigations have tried to hone in on distinctions among the devices that provide it.
A 2023 study compared first-pass intubation success with standard direct laryngoscopy (DL), video laryngoscopy using a hyperangulated blade and VL using standard geometry among emergency medicine residents with varying lengths of postgraduate training.10 While all devices were associated with better first-attempt success as training progressed, video laryngoscopy outperformed direct for all groups, and trainees one year after graduation recorded higher first-pass success with a standard-geometry video laryngoscope than those three years postgraduation did with direct laryngoscopes. By three years after graduation, residents reached overall success rates of 83.6% with DL and 94.6% with VL.
A few years earlier, Turkish researchers looked at hemodynamic responses to tracheal intubation using four different laryngoscopes (classic Macintosh direct, McCoy, C-MAC video and McGrath video) in patients with normal airways.11 They found less fluctuation in heart rate and systolic blood pressure in their McGrath group, as well as shorter intubation times and less incidence of sore throats. “Our findings,” they concluded, “showed that tracheal intubation with [McGrath] is advantageous in preventing cardiovascular stress responses with short intubation time and less sore throat incidence.”
In 2016 Swiss anesthetists simulated difficult airways on more than 700 patients, evaluating six different video laryngoscopes.12 The McGrath model yielded the highest first-pass success rate, 98%, and was the only device with a 95% confidence interval of greater than 90%. The McGrath also produced among the lowest tissue trauma rates.
The 2023 EMMA study was a multicenter randomized trial that compared DL to VL using the McGRATH MAC video laryngoscope from Medtronic.13 Among more than 2,000 adults undergoing elective ETI, first-pass success was higher with the McGrath (94% vs. 82%), and absolute risk reduced by more than 12%. “The other aspect that was really cool was that they also used trainees in that study,” noted Shay. “The first portion was with individuals who were experienced in VL, but then they took brand-new people, inexperienced intubators, and there was again improved first-pass success, 93% for the McGrath and 77% for DL.”
The same lead author reported the 2024 LARA trial, which considered DL versus VL with the McGRATH MAC for rapid sequence intubation.14 The McGRATH MAC yielded better first-pass success (94% vs. 71%) and a lower rate of adverse events and helped reduce intubation times by around five seconds. “True RSI really should be able to be accomplished within about 10 to 15 seconds,” Shay added, “so that alone is striking.”
Other investigators in 2023 evaluated use of a Macintosh-style VL as a first-choice device in the OR.15 This produced an increase in “easy” intubations, from 94.3% to 98.7%, and reduced grade 3–4 Cormack-Lehane views. These authors also found the McGRATH MAC more user-friendly than other devices. A year later, the VIDEOLAR-CAR study tried the McGRATH MAC as the first intubation option for cardiac surgery patients and found it improved the percentage of patients with easy intubations compared to DL (73% to 98%).16
The previous year U.K. authors produced a Cochrane review of the risks and benefits of VL compared to DL, sorting outcomes by VL design (Macintosh-style, hyperangulated and channeled).17 Assessing 222 studies, they found “video laryngoscopes of any design likely reduce rates of failed intubation … with increased rates of successful intubation on first attempt and better glottic views across patient groups and settings.” Hyperangulated designs, they added, likely help against difficult airways and to prevent esophageal intubations.
Two years later, other investigators reanalyzed subgroup data from that meta-analysis, zeroing in on the Macintosh-style devices.18 “This reanalysis,” they concluded, “confirmed the superiority of Macintosh-style VL over Macintosh DL in elective surgical patients.”
WHAT ARE THE KEY POINTS?
That’s a lot of data, and not everything you need to know by a long shot – COVID-19, for instance, drove substantial research into airway management that further distinguished the benefits of video. But if you’re a provider or agency looking for evidentiary guidance to support your care, you can reduce it to a pair of key points: One, video laryngoscopy appears a better option in most all settings and use cases; and two, Medtronic’s McGRATH MAC has much merit as a device of choice.
Combining line-of-sight video with the traditional Macintosh technique, the McGRATH MAC provides advanced optics, ergonomic design and enhanced battery management. It accommodates multiple Macintosh-style blade sizes for children and adults as well as the hyperangulated X3 blade for difficult airways. The company provides numerous additional literature citations in support of its use, including some on cost comparisons – a less-important factor than life and safety to be sure, but inarguably important for EMS organizations.
“You hate to look at it this way, but everyone has to think of the bottom dollar,” said Shay. “We know patients with difficult airways and difficult intubations have substantially higher inpatient and ICU costs and longer lengths of hospital stay. That costs patients and taxpayers significantly more money.”
Reducing that risk on the front end seems a prudent management of EMS agencies’ limited funds.
For more information, visit Medtronic.
REFERENCES
1. “Emergency medical services: At the crossroads.” Institute of Medicine. National Academies Press. 2007. https://nap.nationalacademies.org/catalog/11629/emergency-medical-services-at-the-crossroads
2. “EMS intubation improves with King Vision video laryngoscopy.” Jeffrey L. Jarvis, Sarah Frances McClure, Danny Johns. Prehospital Emergency Care. 2015. https://pubmed.ncbi.nlm.nih.gov/25909850/
3. “Improved success rates using video laryngoscopy in unexperienced users: a randomized crossover study in airway manikins.” Hendrik Eismann, Lion Sieg, Nicola Etti, et al. European Journal of Medical Research. August 2017. https://eurjmedres.biomedcentral.com/articles/10.1186/s40001-017-0268-7
4. “First-pass success intubations using video laryngoscopy versus direct laryngoscopy: A retrospective prehospital ambulance service study.” Christopher M. Eberlein, Isidora S. Luther, Tom A. Carpenter, Luis D. Ramirez. Air Medical Journal. September–October 2019. www.sciencedirect.com/science/article/abs/pii/S1067991X19300343
5. “Association between multiple intubation attempts and complications during emergency department airway management: A national emergency airway registry study.” Michael D. April, Steven G. Schauer, Dhimitri A. Nikolla, et al. American Journal of Emergency Medicine. November 2024. www.sciencedirect.com/science/article/abs/pii/S0735675724004558
6. “The importance of first-pass success when performing orotracheal intubation in the emergency department.” John C. Sakles, Stephen Chiu, Jarrod Mosier, et al. Academic Emergency Medicine. January 2013. https://onlinelibrary.wiley.com/doi/10.1111/acem.12055?msockid=2c649365b0a06ffe08248743b1086e73
7. “Video laryngoscopy in critical care and emergency locations: Moving from debating benefit to implementation.” Marc Pass, Nicola Di Rollo, Alistair F. McNarry. British Journal of Anaesthesia. 2023. www.bjanaesthesia.org/article/S0007-0912(23)00362-8/pdf
8. “Efficacy and adverse events profile of video laryngoscopy in critically ill patients: subanalysis of the INTUBE study.” Vincenzo Russotto, Jean Baptiste Lascarrou, Elena Tassistro, et al. British Journal of Anaesthesia. September 2023. https://pubmed.ncbi.nlm.nih.gov/37208282/
9. “Video versus direct laryngoscopy for tracheal intubation of critically ill adults.” Matthew E. Prekker, Brian E. Driver, Stacy A. Trent, et al. New England Journal of Medicine. June 2023. www.nejm.org/doi/full/10.1056/NEJMoa2301601
10. “First-attempt intubation success among emergency medicine trainees by laryngoscopic device and training year: A national emergency airway registry study.” Samuel I. Garcia, Benjamin J. Sandefur, Ronna L. Campbell, et al. Annals of Emergency Medicine. June 2023. https://pubmed.ncbi.nlm.nih.gov/36669924/
11. “Haemodynamic response to four different laryngoscopes.” Demet Altun, Achmet Ali, Emre Çamcı, et al. Turkish Journal of Anaesthesiology & Reanimation. December 2018. https://turkjanaesthesiolreanim.org/articles/doi/TJAR.2018.59265
12. “Evaluation of six video laryngoscopes in 720 patients with a simulated difficult airway: a multicentre randomized controlled trial.” Maren Kleine-Brueggeney, Robert T. Greif, Patrick Schoettker, et al. British Journal of Anaesthesia. May 2016. www.sciencedirect.com/science/article/pii/S0007091217303653
13. “A multicentre randomised controlled trial of the McGrath Mac video laryngoscope versus conventional laryngoscopy.” Marc Kriege, Ruediger R. Noppens, Tim Turkstra, et al. Anaesthesia. June 2023. https://pubmed.ncbi.nlm.nih.gov/36928625/
14. “A comparison of the McGrath video laryngoscope with direct laryngoscopy for rapid sequence intubation in the operating theatre: a multicentre randomised controlled trial.” Marc Kriege, P. Lang, C. Lang, et al. Anaesthesia. February 2024. https://pubmed.ncbi.nlm.nih.gov/38345268/
15. “Video laryngoscopy as a first-intention technique for tracheal intubation in unselected surgical patients: a before and after observational study.” Audrey De Jong, Thomas Sfara, Yvan Pouzeratte, et al. British Journal of Anaesthesia. October 2022. https://pubmed.ncbi.nlm.nih.gov/35811139/
16. “Impact of universal use of the McGrath video laryngoscope as a device for all intubations in the cardiac operating room. A prospective before-after VIDEOLAR-CAR study.” Manuel Taboada, Ana Estany-Gestal, María Rial, et al. Journal of Cardiothoracic and Vascular Anesthesia. July 2024.
17. “Video laryngoscopy versus direct laryngoscopy for adults undergoing tracheal intubation: a Cochrane systematic review and meta-analysis update.” Jan Hansel, Andrew M. Rogers, Sharon R. Lewis, Tim M. Cook, Andrew F. Smith. British Journal of Anaesthesia. October 2022. https://pubmed.ncbi.nlm.nih.gov/35820934/
18. “Macintosh-style video laryngoscope use for tracheal intubation in elective surgical patients revisited: a sub-analysis of the 2022 Cochrane review data.” Alistair F. McNarry, Patrick Ward, Ubong Silas, Rhodri Saunders, Sita J. Saunders. Patient Safety in Surgery. May 2024. https://pmc.ncbi.nlm.nih.gov/articles/PMC11134739/
