DIRECT LARYNGOSCOPY: BASIC SKILL OR OBSOLETE TECHNOLOGY?

When it’s time to insert an endotracheal tube, for decades anesthesiologists have utilized a direct laryngoscope. Direct laryngoscopy (DL) is a difficult skill to acquire, but all anesthesiologists become masters of it. Enter the video camera, which changed surgical practice. Open abdominal surgeries became laparoscopies, with the surgeon focused on a two-dimensional video screen while he or she manipulated instruments inside the abdomen. The video camera also changed orthopedic surgery, as most knee and shoulder surgeries (other than joint replacements) became arthroscopies, with the surgeon focused on a two-dimensional video screen while he or she manipulated instruments inside the joint. In 2001, with the invention of the first video laryngoscope (VL), the GlideScope, anesthesiologists could “see around corners” with the video camera located at the end of the laryngoscope blade positioned inside the airway of the patient. The anesthesiologist could indirectly visualize the patient’s vocal cords, which enabled the placement of the endotracheal tube into the windpipe. The VL was a wonderful advance in anesthesiology, especially when used to successfully manage patients who presented difficult intubations. The question has been posed: should we move to using VL universally for all endotracheal intubation attempts?  Will the advanced technology of VL push DL into obsolescence, or will anesthesiologists cling to the past and continue to utilize DL for routine cases, with VL as a backup tool?

I’m writing from the perspective of a busy clinician who has placed tens of thousands of endotracheal tubes with DL. I utilize VL for difficult airway cases or emergency cases. In my practice, about 98% of cases which require an endotracheal tube are easily managed with routine DL. But in every anesthetizing location we work at, we have a video laryngoscope available if an anesthesiologist needs it for placing a difficult endotracheal tube. Having a video laryngoscope available wherever a difficulty airway may occur is a standard of care. The 2022 American Society of Anesthesiologists Difficult Airway Algorithm states, “meta-analyses of randomized controlled trials comparing video-assisted laryngoscopy with direct laryngoscopy in patients with predicted difficult airways reported improved laryngeal views, a higher frequency of successful intubations, a higher frequency of first attempt intubations, and fewer intubation maneuvers with video-assisted laryngoscopy.”  The flowchart diagram of the Difficult Airway Algorithm reads: “Consider the relative merits and feasibility of basic management choices: [including] video-assisted laryngoscopy as an initial approach to intubation.”

Considering video laryngoscopy as an initial approach to intubation in every patient with a difficult airway is a standard of care. But using a video laryngoscope for every initial attempt at intubation on every case, difficult or routine, is not a current standard of care.

Advantages of video laryngoscopy include:

• Superior visualization of the vocal cords on the initial laryngoscopy attempt. A recent 2024 publication in JAMA looked at 8429 surgical procedures from March 2021 to December 2022 in a single institution. More than one intubation attempt was required in only 1.7% of the patients randomized to video laryngoscopy, vs 7.6% of the patients randomized to direct laryngoscopy (P < .001). Intubation failure occurred in only 0.27% of patients using video laryngoscopy vs 4.0% of patients using direct laryngoscopy (P < .001). The conclusion was that “(hyperangulated) video laryngoscopy decreased the number of attempts needed to achieve endotracheal intubation compared with direct laryngoscopy at a single academic medical center.”
• A higher overall first-pass success rate with VL (89.1%) compared to DL (77.7%) in patients with anticipated or anatomically difficult airways.
• An ease of teaching because both the attending and the trainee can see the video screen. It’s easier to train non-anesthesiologists (emergency room MDs, critical care internal medicine MDs, EMTs and helicopter trauma RNs) to use VL versus DL. For non-anesthesiologists, who will not undergo three years of anesthesia residency training to become DL experts, learning video laryngoscopy instead of direct laryngoscopy makes sense.

Limitations of video laryngoscopy include:

• The price of purchasing one GlideScope for our multispecialty ambulatory surgery center was $14,000. The cost of each single-use GlideScope blade is $38. (https://www.partssource.com/parts/verathon-medical-inc-formerly-diagnostic-ultrasound/02700679?pspn=ps44pahadae) The cost of purchasing the smaller and more portable McGrath video scope is $3899, and the cost of each single-use McGrath blade is $6.70.  Consider this: if a hospital purchased 20 McGrath scopes at $3899, with the small pocket size of a McGrath scope it would only be a matter of time before some of the scopes would disappear. Of course none of the anesthesiologists or operating room personnel are dishonest, but preventing theft of these small valuable devices would be difficult.
• The handheld McGrath video scope has a 2.5-inch video screen. In my experience with using this product over 4 – 5 years, the small size of the screen was a significant disadvantage compared to the larger 6.4-inch HD screen on a GlideScope.
• Superior visualization of the vocal cords with VL does not mean it will be easy to actually insert the endotracheal tube into the trachea, especially with hyperangulated blades such as the GlideScope LoPro. The indirect view of the larynx can require a hyperangulated introducer inside the endotracheal tube, and learning this skill requires significant experience before an operator can become facile with all VL intubations with the hyperangulated blades.
• The KISS (Keep It Simple Stupid) Principle is a valuable concept in aviation as well as anesthesia. The KISS Principle does not point toward using expensive VL technology for every easy intubation. The overwhelming majority of patients who need endotracheal intubation have normal airways and intubating them with DL will work without any disadvantage. But because some difficult laryngoscopies are unexpected, a video scope needs to be immediately available if DL is difficult or impossible.
• A career of airway management requires a variety of skills to keep patients oxygenated and alive. If today’s anesthesia trainees don’t become competent with DL, what will happen to them if VL is unavailable in some emergency or acute care situation? If current training programs make universal use of VL to teach anesthesia residents, it’s possible that when these residents graduate, that the practice of DL will cease or fade away. Does any fully trained anesthesiologist think this is a wise direction?

DL versus VL for all initial intubation attempts—what should your facility do?

It’s imperative to have video laryngoscopy available at all anesthetizing locations, but the economics are clear. If your facility has 20 operating rooms and you purchase one VL scope for every operating room—in addition to VL scopes for labor and delivery, endoscopy suites, the emergency room, and all out-of-operating-room locations—the upfront expense to buy all these video scopes will be significantly higher than relying on DL for initial airway management. Ongoing expenses will also include hundreds of single-use $38 GlideScope blades or $6.70 McGrath blades. The university hospital where I work owns multiple GlideScopes and C-MAC video scopes but stops far short of one for every room. It’s not possible to use VL for every initial endotracheal intubation because of the lack of supply of video scopes. At 0730 in the morning when dozens of cases start simultaneously in multiple ORs, it’s already difficult to secure one of the video scopes for some ORs, because other attendings and trainees have already reserved the equipment for their cases.

The ambulatory surgery center where I work as Medical Director owns one GlideScope, which is used sparingly whenever a difficult intubation or a failed first attempt DL occurs. Our inventory of $38 blades is never low because we do not use the VL on every patient. In this freestanding surgery center, where most patients are healthy, the utilization of the GlideScope is approximately 1 – 2 out of every 100 patients who require endotracheal intubation. The costs of using the disposable GlideScope $38 blades for every intubation would far exceed our current cost of autoclaving reusable Macintosh and Miller DL blades.

Academic publications to date have not quantitated the increased costs incurred by utilizing video scopes and disposable video blades for every intubation versus using reusable DL blades. Money talks. VL is extremely valuable for the management of difficult airways, but VL for every patient makes no fiscal sense. Would the adoption of VL for every initial intubation attempt in the operating room decrease the healthcare dollars spent in subsequent ICU care, inpatient hospital care, and/or malpractice lawsuit expenses? There’s no data to validate that claim as of today.

Video laryngoscopy is a terrific advance in airway management and should be available wherever endotracheal intubation is performed, but VL for anesthesiologists for initial endotracheal intubation attempts on every patient? No. For non-anesthesiologists, who will not undergo three years of anesthesia residency training to become DL experts, learning video laryngoscopy instead of direct laryngoscopy makes sense.

For anesthesiologists, direct laryngoscopy will continue to be a basic skill.