Which is better for critically ill patients—direct laryngoscopy (DL) of video laryngoscopy (VL)?
This question has ignited an intense debate within academic, emergency medicine, and critical care communities as 13 to 20 million intubations are performed annually in the United States alone. Though the conclusions from available literature appear mixed, recent case studies have consistently advocated that VL should be the standard of care. It’s important to note, however, that neither technique offers 100% successful intubation.
In this article, Hospital Procedures Consultants tackles the issue with research-backed insights. We explore the pros and cons of video laryngoscopy and why it’s better than direct laryngoscopy. By the end of this piece, clinicians will be better positioned to make more informed healthcare decisions for their patients.
Evidence Supporting the Use of Video Laryngoscopy
A systematic review of 222 studies showed that VL reduces rates of failed intubation—especially when it is used on known or predicted difficult airways. It increases the rates of success on the first intubation attempt by offering more extensive glottic views.
This is backed by a randomized controlled trial of critically ill adults with similar characteristics across 7 emergency departments and 10 intensive care units in the United States. Patients who were prisoners, pregnant, cases unsuitable for randomization, and patients with contraindications for certain blade types were excluded. Certain aspects were not standardized, including pre-oxygenation, medications, blade size, and positioning.
This led to two notable outcomes:
- The use of a VL resulted in a higher incidence of successful intubation on the first attempt (tube was inserted into the trachea after a single insertion of the blade and tube or bougie) compared to DL.
- Severe cases of hypotension, hypoxemia, cardiac arrest, and even death within two minutes following the procedure. There was also a greater reliance on vasopressors.
Seventy percent of intubations were performed in emergency departments and pneumonia (30%) or altered mental status (45%) were the primary reasons for intubation.
Another 8-month research study in 2022 was conducted on 1,420 patients. However, the trial was stopped by the data safety and monitoring board because the criteria for efficacy had been met. Certain patient characteristics were similar across the groups: the mean age was around 55 while mean body mass indexes were 26.5 kilos per square meter. Seventy percent of intubations were performed in emergency rooms with pneumonia (30%) and altered mental states (45%) as the primary indications for intubation in the majority of cases.
One thing is certain: VL is safer than DL as repeated conventional tracheal intubation attempts may contribute to patient morbidity. Naturally, the extent of benefits varies across device types.
Since VL can be combined with fiberoptic bronchoscope (FOB) and other tools for enhanced visualization, it could be used to facilitate a reduction in trauma to the airway. However, while FOB can minimize cervical spine movement during intubation, VL is more likely to be chosen than FOB (90% vs. 4%, respectively) in emergency situations as it is more readily available and much faster to set up.
Does Blade Geometry Matter?
As highlighted in an editorial article published in the Anesthesia & Analgesia Journal, there is some sort of standardization in direct laryngoscope blade designs (Macintosh & Miller), which goes a long way toward ensuring efficient procedures.
Unfortunately, this doesn’t extend to VL. In this technique, blades are classified by their geometry, which dictates their efficacy and performance for one maneuver over another. For example, a 2016 multicentre randomized controlled trial demonstrated how broadly first-attempt success rates vary among devices, from 98% with the McGrath, 95% (C-MAC D-Blade), 87% (KingVision), 85% (Glidescope and Airtraq) to 37% (A.P. Advance). This difference may be due to different blade geometries used (Mac vs hyperangulated blades) by these different companies.
Since every blade serves a different purpose, there can be no standardization. An attempt to do so could lead to unexpected difficulty with a different device as a failure of one airway management maneuver could contribute to the failure of the next.
Can the Use of Video Laryngoscope Degrade Clinicians’ Skills?
The use of a video laryngoscope improves the view of the larynx, which can increase the chances of successful intubation among residents with minimal experience.
Even in the multicenter, randomized trial, most intubations were performed by relatively inexperienced physicians. Over ninety percent were emergency management residents or critical-care personnel who previously performed a mean of 50 intubations. The median of previous VL intubations performed was 0.69. They used VL in the first attempt in 100% of the patients and 98.9% of the patients in the DL group, reporting successful first-pass intubation in 85.1% and 70.8%, of cases, respectively.
Their adherence to protocols was excellent. All of the patients in the VL and DL groups used their respective methods on the first attempt. However, the VL group reported significantly more grade 1 views versus the DL group (76.3% vs. 44.7%).
Successful first-attempt intubations were noted in 85.1% of cases in the VL group, higher than the DL group’s 70.8%. During the trial, several sensitivity checks were conducted and demonstrated a significant difference in disease-oriented outcomes.
Meanwhile, the previously mentioned complications were marginally higher in the VL group (21.4%) compared to the DL group (20.9%). VL also showed shorter intubation periods, higher success rates on first-attempt intubation as well as the absence of grave complications and esophageal intubation, leading the study to favor video laryngoscopy.
The trial employed independent observers for data collection and a multi-site approach. The groups to which the patients belonged were undisclosed to minimize bias.
Some of its minor limitations included allowing clinicians to choose the size and type of blade they wanted to use and a similar lack of standardized protocols in other parts of the procedure. Hence, these might have had an impact on patient complications and morbidity.
Overall, the study cannot be used as a basis for definitive findings since over 90% of the operators were inexperienced, with the majority primarily using VL in their practices.
After grouping them based on previous experiences, the difference between groups grew to 26.1%. The results favored VL operators who had performed less than 25 intubations in the past versus operators who had conducted more than 100 intubations (5.9%).
The ability of VL to improve outcomes and accessibility to the necessary equipment (Cook and Kelly reported that 92% of hospitals offer VL access) may cause airway managers to use it as the primary method during intubation. The concern now is whether DL’s infrequent use might erode healthcare practitioners’ direct laryngoscopy skills. Despite the advantages of video laryngoscopy, direct laryngoscopy is still a critical skill for clinicians who attempt endotracheal intubation and those attempting to re-intubate patients after an initial attempt at VL fails.
While it’s a barrier to consider, data shows that fewer than a third of hospitals in the UK reported widespread use of VL. We expect the numbers to be similar in the US. Hence, the concern regarding the degradation of DL skills may not be worth mentioning once the operator’s experience level with intubation increases.
According to research, there will be no difference between the use of video or direct laryngoscopy as the emphasis will be on patient safety. Since it is the primary goal in healthcare, we must choose awake fiberoptic laryngoscopy where indicated.
Sharpen Your Skills With Hospital Procedures Consultants
These pros and cons of video laryngoscopy, meticulously recorded in literature, show that while it is beneficial, it doesn’t render other techniques irrelevant. We must also consider that many of the studies lack standardization, making the results inconclusive.
Instead of being completely reliant on VL, airway managers must develop proficiency in other methods of intubation so they can apply the best methods of care to a variety of cases.
Hospital Procedures Consultants can help you master various intubation techniques with our Airway Procedures Course. By enrolling, you’ll learn about awake video laryngoscopy, the use of video laryngoscopy, and more.
Resources
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