**Table 1.**

*Special Considerations in Human Airway Management*

algorithm in intensive care units (ICUs) [22].

**3. Technique of videolaryngoscopy**

or non-channeled one (**Figures 1**–**3**).

all endoscopic techniques.

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

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

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

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

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

**2. History of videolaryngoscopy**

intubation.

**230**

intubating stylets.

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

**Figure 1.** *Airtraq® as an example of the channeled videolaryngoscope (own photography).*
