Recent trials demonstrate higher first-pass intubation success rates with video laryngoscopy compared to direct laryngoscopy, prompting calls for widespread adoption.

By Alyx Arnett


The debate between direct and video laryngoscopy has been ongoing, but new research is swinging the pendulum in favor of video laryngoscopy. Large-scale studies show that it increases the likelihood of improving first-attempt intubation success.

Traditionally, tracheal intubation—where an endotracheal tube is placed by visualizing the vocal cords through the mouth—has been performed using direct laryngoscopy. This method relies on the clinician’s line of sight, making the process heavily dependent on their skill and experience.

The advent of video laryngoscopy, which utilizes a camera to display the path to intubation on a screen, has offered a new approach but has been slow to be adopted, with 80% of intubations in emergency departments (EDs) and intensive care units (ICUs) globally still being performed with direct laryngoscopes.1

However, video laryngoscopy has gained popularity over the past several years, partly due to the COVID-19 pandemic. In March 2020, consensus guidelines were released for managing the airway in COVID-19 patients, stating that “laryngoscopy should be undertaken with the device most likely to achieve prompt first-pass tracheal intubation in all circumstances in that operator’s hands—in most fully trained airway managers this is likely to be a video laryngoscope.”2

Matt Prekker, MD, MPH, specializing in emergency medicine and pulmonary and critical care medicine at Hennepin Healthcare, said this method was safer for staff. “It allowed the person intubating the patient who potentially would have COVID to stay at least an arm’s length away from their mouth and use the camera and the screen to get your view of the vocal cords and pass the tube, instead of direct laryngoscopy, where you’re manipulating the airway soft tissues with the blade and getting your face right down there to get the view of the vocal cords through the mouth,” he said.

But at that time, the best evidence of the benefit of video laryngoscopy over direct laryngoscopy to the patient was unclear. The most comprehensive study then was a 2017 randomized clinical trial involving 371 adult patients requiring intubation in seven ICUs in France.3 The study sought to determine whether video laryngoscopy increases first-pass attempt success—a factor thought to reduce complications and improve patient outcomes—over direct laryngoscopy. Researchers concluded that it did not.3

However, since then, larger studies have provided new evidence favoring video laryngoscopy to improve first-pass success rates for intubation. “We have the data now to say definitively that if you care about successful intubation on the first attempt—which I think you should, because that’s in every study so tightly linked to complications—that you should use video laryngoscopy,” said Prekker, also an associate professor at the University of Minnesota Medical School.

Launching a New Study

Prekker and co-investigators launched the DirEct versus VIdeo LaryngosCopE (DEVICE) trial in 2022 to tackle a pressing question medical centers using both methods had: Does video laryngoscopy have an edge over direct laryngoscopy in increasing the likelihood of successful first-attempt intubation?4

The trial was conducted at 17 EDs and ICUs, with critically ill adults undergoing tracheal intubation being randomly assigned to a video or direct laryngoscope group.

Halfway through the trial—after approximately 1,100 patients were enrolled—the Data and Safety Monitoring Board performed a preplanned unblinded analysis of the primary outcome (first-attempt intubation success) and recommended stopping the trial early.

“To our surprise, they actually came back and said that we should stop the trial because video laryngoscopy is significantly more effective than direct laryngoscopy at improving first-attempt success,” said Prekker. “So we had our answer much earlier than we thought.”

Results of the DEVICE Trial

Among the 1,417 patients included in the final analysis, successful intubation on the first attempt occurred in 85.1% of patients in the video laryngoscope group and 70.8% in the direct laryngoscope group.4

The 14.3 percentage point difference was more than twice what researchers had anticipated.

“So, for our patients, I think that’s a big deal. If I were being intubated, I’d want it to be done as quickly and safely as possible, especially when you’re really sick and it’s an unplanned situation. And so we saw that. It was a significant difference and one that I think is very clinically important,” said Prekker.

A second exploratory outcome looking at the incidence of severe complications didn’t find a significant difference between the groups (21.4%% in the video laryngoscope group and 20.9% in the direct group).4 Prekker estimated the trial would need to be seven to 10 times the size to show a significant benefit in that outcome. “We still strongly believe first-attempt success is tightly associated with the risk of complications,” he said.

Strengths of the DEVICE trial, which may explain the differing outcomes compared to the 2017 study, included the involvement of hundreds of operators using various types of laryngoscopes and a sample size four times larger than the earlier study. The 2017 study, by contrast, only compared the McGrath MAC video laryngoscope to the direct Macintosh laryngoscope.

The researchers also speculated that the accelerated learning curve during the COVID-19 pandemic may have made operators more proficient with video laryngoscopy.

The research was published in the New England Journal of Medicine in June 2023. 

More Evidence Supporting Video Laryngoscopy

A March 2024 study provided further evidence supporting the use of video laryngoscopy in improving first-attempt intubation success, this time focusing on patients in the operating room.5 Kurt Ruetzler, MD, from the department of anesthesiology at Cleveland Clinic and study author, was motivated to conduct the study due to the fact that intubation—despite being widely considered safe, quick, and straightforward—carries significant risks.

“In fact, it’s dangerous. Airway management is associated with morbidity, like bradycardia, tachycardia, hypotension, hypoxemia. Pre-intubation attempts are even associated with increased risk of mortality,” said Ruetzler, who’s also an associate professor of anesthesiology at Lerner College of Medicine at Case Western Reserve University. “If you can find a better technique, it just increases the mid- and long-term outcomes for patients.”

The cluster randomized multiple crossover clinical trial was conducted at a single US academic hospital from March 2021 to December 2022 and included 7,736 adult patients receiving 8,429 surgical procedures. Patients were having elective or emergent thoracic, cardiac, or vascular surgical procedures and required endotracheal intubation for general anesthesia.

Two sets of 11 operating rooms were randomized on a weekly basis to perform either hyperangulated video laryngoscopy or direct laryngoscopy for the initial intubation attempt.

Operating Room Results

In the video laryngoscopy group, 98.3% of surgical procedures were successful on the first attempt, compared to 92.4% in the direct laryngoscopy group.5 “That’s a huge, four-fold difference in patients requiring more than one intubation if you intubate the patient with direct laryngoscopy,” Ruetzler said. “It’s unbelievable.”

Intubation failure was lower in the video laryngoscopy group, occurring in 0.27% of surgical procedures compared to 4% of procedures in the direct laryngoscopy group.5

The incidence of airway and dental injuries was similar between the two methods, with 0.93% (41 injuries) in the video laryngoscopy group and 1.1% (42 injuries) in the direct laryngoscopy group.5

Video Laryngoscopy: The New Gold Standard?

International guidelines indicate that both direct and video laryngoscopy are acceptable for tracheal intubation in critically ill adults.6 However, Prekker and Ruetzler believe there is now enough data to support a shift to video laryngoscopy for all patients.

“The evidence is clear video laryngoscopy is superior, and clinicians have to now make it happen and translate it into clinical practice—or, in other words, get rid of direct laryngoscopy and use video laryngoscopy as a default technique for all patients,” said Ruetzler.

Still, several barriers to adoption remain, according to the clinicians. One is that video laryngoscopy is generally more expensive than direct laryngoscopy. However, Ruetzler said the overall cost is likely comparable when considering the increased need for multiple intubation attempts with direct laryngoscopy.

Another major barrier is resistance to change among experienced clinicians. “We have a lot of colleagues who said, ‘I was using direct laryngoscopy for the last 20 years, and I think I was successful. Why should I change?’ Or, in fact, ‘I don’t want to change because it’s my practice for the last 20 years,’” said Ruetzler. “And to these colleagues, I just want to say you’re just wrong. The assumption that you are doing a great job with direct laryngoscopy is just wrong.”

Adrian D’Angelo, MSN, NP, medical affairs senior program manager at Medtronic, manufacturer of the McGrath MAC video laryngoscope, has seen this resistance himself. “What we’re doing is we’re showing them what all the evidence says,” he said. “…That’s what people are looking at to get past any barriers.”

Those adopting the technology—which D’Angelo noted has seen increased uptake over the past several years—also value that video laryngoscopes are lightweight and portable.

“You can pick up a McGrath and put it in your pocket with a blade, and you can run to wherever you need to be in the hospital,” he said.

Further Research to Guide Clinicians

While Prekker said “the question’s now answered” regarding which method improves first-attempt intubation success, the next question to explore is which type of video laryngoscope should be used.

“One of the strengths of our trial was we didn’t force the operator into just one specific manufacturer. They could use whatever video laryngoscope system they had at their hospital, so I think we got generalizable data from the DEVICE trial,” Prekker said. “But one important follow-up question then is which system is better.”

Prekker would like to see a trial comparing the effectiveness of hyperangulated blades versus Macintosh-shaped blades in video laryngoscopy. “That would help guide clinicians in that regard,” he said.

RT

Alyx Arnett is associate editor of RT. For more information, contact [email protected].

Photo credit: Medtronic

References

  1. Russotto V, Myatra SN, Laffey JG, et al. Intubation practices and adverse peri-intubation events in critically ill patients from 29 countries [published correction appears in JAMA. 2021 Jun 22;325(24):2507]. JAMA. 2021;325(12):1164-72.
  2. Cook TM, El-Boghdadly K, McGuire B, et al. Consensus guidelines for managing the airway in patients with COVID-19: Guidelines from the Difficult Airway Society, the Association of Anaesthetists the Intensive Care Society, the Faculty of Intensive Care Medicine, and the Royal College of Anaesthetists. Anaesthesia. 2020;75(6):785-99.
  3. Lascarrou JB, Boisrame-Helms J, Bailly A, et al. Video laryngoscopy vs direct laryngoscopy on successful first-pass orotracheal intubation among ICU patients: a randomized clinical trial. JAMA. 2017;317(5):483-93.
  4. Prekker ME, Driver BE, Trent SA, et al. Video versus direct laryngoscopy for tracheal intubation of critically ill adults. N Engl J Med. 2023;389(5):418-29.
  5. Ruetzler K, Bustamante S, Schmidt MT, et al. Video laryngoscopy vs direct laryngoscopy for endotracheal intubation in the operating room: a cluster randomized clinical trial. JAMA. 2024;331(15):1279-86.
  6. Higgs A, McGrath BA, Goddard C, et al. Guidelines for the management of tracheal intubation in critically ill adults. Br J Anaesth. 2018;120(2):323-52.