**Abstract**

Videolaryngoscopy has emerged not only as an alternative to direct laryngoscopy for airway intubation in adults and children but also as a new diagnostic and therapeutic tool in head and neck surgery. Videolaryngoscopy has a great advantage over direct laryngoscopy because it has been proven to reduce difficult views of the laryngeal opening (glottis). The success of intubation with a videolaryngoscope depends on both the type of device used and the experience of the operator. Technical details, such as the device's size and blade choice, properly reshaping the endotracheal tube, and customized hand-eye coordination, are all particularly important for targeting the endotracheal tube toward the glottis. Besides its clinical role in airway management, videolaryngoscopy is an excellent tool for education and medicolegal recording.

**Keywords:** airway management, videolaryngoscopy, direct laryngoscopy, anesthesia, intensive care medicine, emergency, history, education

#### **1. Introduction**

Videolaryngoscopy represents a significant improvement in endotracheal intubation and thus an improvement in airway safety. Namely, it is well known that to increase airway safety, it is necessary to apply the appropriate concept of airway visualization on which airway strategies and airway algorithms are based [1]. It is generally believed that improving the visualization of the laryngeal opening (glottis) as the most important airway structure for intubation significantly increases the success of intubation.

The classic concept of endotracheal intubation by direct laryngoscopy is based on the alignment of three axes (oral, pharyngeal, and laryngeal) to expose the laryngeal opening (glottis) to the external observer's eye, who places the tube through the glottis under the full control of eyesight [2]. This requires an appropriate head and neck position, a laryngoscope, and a precise laryngoscope application technique [3]. Often, the position adjustment should be instituted in case of poor visualization of the glottis [4]. Videolaryngoscopy uses optical technology to improve glottis visualization without the need to align the three axes of the airway, which might be especially useful in neck mobility limitations when it is not possible to extend the neck [5, 6]. In addition to better visualization of the glottis, videolaryngoscopy has proven to be a very successful intubation technique in operators with little or no experience [7–9], involves all airway team members [10–12], and is an important tool for perioperative airway assessment, airway care education, and medicolegal intubation recording [12, 13].

#### **2. History of videolaryngoscopy**

Although videolaryngoscopy as a technique of airway management has been an extremely popular topic for the last decade, the fact is that the principle of indirect airway visualization, on which it is based, is older than direct laryngoscopy. In 1829, Benjamin Guy Babington (1794–1866) described the first "glottoscope" or "glottiscope," which consisted of a speculum to displace the tongue (a tongue depressor) and a system of mirrors to visualize the larynx, with sunlight for illumination [14–16]. Yet since 1895, when Alfred Kirstein (1863–1922) developed the "autoscope" that had an external electrical light source, the developmental pathway of laryngoscopy has focused on direct laryngoscopy [15, 16]. Consequently, since the 1940s, when the Macintosch and Miller blade were introduced [17], direct laryngoscopy has been the gold standard of endotracheal intubation.

In 1998, Markus Weiss incorporated fiberoptic fibers into a direct laryngoscope with a Macintosh blade [18]. In 2001, John Pacey introduced the first videolaryngoscope called the Glidescope®, and since then the number of different devices using videolaryngoscopy has grown [17]. In 2013, the American Society of Anesthesiologists (ASA) suggested the use of videolaryngoscopy as the first choice in airway management in its algorithm of airway management [19]. The Difficult Airway Society (DAS), in the 2015 algorithm, recognized the use of videolaryngoscopy as part of the airway management and suggested to all anesthesiologists the adoption of the videolaringoscopy skills [20]. It is recommended that videolaryngoscope should be immediately available for all obstetric general anesthetics [21]. In 2017, DAS presented videolaryngoscopy as an equivalent technique to direct laryngoscopy in the first attempts of intubation in the airway management algorithm in intensive care units (ICUs) [22].

#### **3. Technique of videolaryngoscopy**

The technique of videolaryngoscopy depends on the type of device used.

**Table 1** lists some of the videolaryngoscopes. The division of videolaryngoscopes into the channeled and non-channeled devices has practical implications as the technique of videolaryngoscopy also differs significantly whether it is channeled or non-channeled one (**Figures 1**–**3**).

Non-channeled devices are further divided depending on the type of blade, which can be of the Macintosh, Miller, or hyperangular type, which also further influences the choice of technique (**Figure 4**). Blades can be manufactured from plastic for a single use or from metal for a multiple use. The screen can be on the device itself (**Figure 5**) or on a separate external monitor (**Figure 6**), which can be placed on the side or above the patient's chest. The position of the monitor does not significantly affect the technique, but it requires good eye-hand coordination like all endoscopic techniques.

It is important to note that videolaryngoscopy, in broader meaning, includes all devices that assist laryngoscopy by video technology. Besides the above described videolaryngoscopes, it includes different video intubating stylets and videoendoscopes, too. These devices are equipped with an inbuilt camera and light source [23, 24]. Compared to the older versions of videostylets which were designed as rigid linear rods, the newer intubating stylets are often S-shaped and semiflexible with deflectable tips [25, 26]. The devices can have an eyepiece at their end or can be attached to monitor to allow watching at the screen. **Table 2** lists some video intubating stylets.

**231**

**Figure 1.**

*Videolaryngoscopy, the Current Role in Airway Management*

**Type Blade type Name Manufacturer** Channeled N/A Airtraq® Prodol, Vizcaya, Spain

> Pentax AWS® Pentax-AWS, Ambu Glen Burnie MD, USA King Vision® King System, Nobesville, IN, USA

Airway Scope® Pentax, Tokyo, Japan

McGrath MAC® Aircraft Medical, Edinburgh,

Scotland

APA™ MAC Venner Medical, Singapore, Singapore Infinium ClearVue® QuadMed, Inc. Jacksonville, FL, USA AP Venerscope® Intravent Direct, Maidenhead, UK Truview PCD™-R Truphatek International Limited,

C-MAC D-blade® Karl Storz, Tuttlingen, Germany McGrath Series 5® Aircraft Medical, Edinburgh,

Netanya, Israel

Scotland

APA™ DAB & U-DAB Venner Medical, Singapore, Singapore Infinium Clear Vue® Quamed, Inc. Jackonsville, FL, USA

Glidescope, Verathon, WA, USA

Glidescope, Verathon, WA, USA

Res-Q-Scope II N/A

Glidescope® Core™, Titanium™ Spectrum™

Glidescope® Core™, Titanium™ Spectrum™

Angulated blade Storz V-MAC®/C-MAC® Karl Storz, Tuttlingen, Germany

**3.1 Technique of videolaryngoscopy with a channeled videolaryngoscope**

*Airtraq® as an example of the channeled videolaryngoscope (own photography).*

The tube is placed in the dedicated groove of the device (**Figure 7**). The tube or the channel on the device can be lightly lubricated to reduce friction. During this preparation, make sure that the lubricant does not obscure the light source and the outer glass of the screen. The size of the tube should be adjusted to the size of

*DOI: http://dx.doi.org/10.5772/intechopen.93490*

Hyperangulated

*Channeled and non-channeled videolaryngoscopes [10, 15, 23, 24].*

blade

Nonchanneled

*N/A, not applicable.*

**Table 1.**


*Videolaryngoscopy, the Current Role in Airway Management DOI: http://dx.doi.org/10.5772/intechopen.93490*
