INTRODUCTION
Traditional laryngoscopes require the operator to achieve a direct line of site of the glottis by aligning the oral, pharyngeal, and laryngeal axes (Chapter 13). Video laryngoscopes capitalize on a video camera, which is mounted on a rigid blade, to circumvent the need for a straight line of sight, while providing superior views of the glottis and surrounding spaces (Chapter 14). Optically enhanced devices are those laryngoscopes that allow the operator to visualize the glottis without creating a straight line of sight, but without using video or fiber-optic technology. The glottic view is obtained by the use of less expensive optics consisting of combinations of prisms, mirrors, and lenses. The relatively inexpensive cost of the technology is one of the major benefits of these devices when compared with the more expensive fiber-optic and video devices. Many of these devices also offer video capability through attachable video cameras. The addition of video capability provides a magnified view of the glottis, and enhances education by allowing other providers to visualize what the airway manager is observing. There are only two true optical devices of relevance to emergency airway management, the Airtraq and the Truview.
DEVICES
Airtraq
Components
The Airtraq is a single-use, disposable laryngoscope system that provides the operator with a magnified view of the glottic structures. The Airtraq is now available in two models: the single-use, all-in-one, ready-to-use Airtraq SP and the two-piece Airtraq Avant with reusable optics and single-use blade. The Airtraq SP comes in four sizes for conventional orotracheal intubations, with two additional special application devices. The conventional devices begin with size 0/Infant, using endotracheal tube (ETT) sizes 2.5 to 3.5, up through size 3/Regular, using ETT sizes 7.0 to 8.5 (Fig. 15-1). Both of the Avant blades and the conventional orotracheal SP devices have an ETT channel in which the ETT is preloaded before insertion. The channel guides the ETT directly toward the glottic opening (Fig. 15-2). Airtraq also offers Airtraq SP Nasotracheal that lacks the ETT channel and is intended for use during nasotracheal intubation. This device is inserted through the mouth to facilitate nasotracheal intubations with the assistance of glottic visualization. An additional specialty device, the Airtraq SP Double Lumen has a larger channel that will accommodate double-lumen endobronchial tubes. The Airtraq devices have a relatively narrow profile. The minimal mouth opening required is 16 mm for the Airtraq size 3 and 15 mm for the Airtraq size 2.
• FIGURE 15-1. Airtraq SP Devices. Sizes range from Infant/size 0, the gray-colored blade in the background, to Regular/size 4, the light blue device in the foreground. The orange device is the nasotracheal intubation device that lacks the tube channel, and the pale yellow device is the double-lumen device with the larger endobronchial tube channel.
All of the Airtraq SP devices are made of plastic and are designed for single use. They cannot be cleaned or sterilized, and they will not function properly if this is attempted. This single-use attribute makes the Airtraq SP particularly suitable for field use by both emergency medical services (EMS) and military personnel. The devices are powered by three AAA batteries, which will provide approximately 90 minutes of operating time. The shelf life is approximately 2 years. The Airtraq SP is turned on by pressing a button on the top of the unit that illuminates a low-heat light-emitting diode. The device has a built-in antifog mechanism. A rubber eyepiece is connected to the optical channel. This rubber eyepiece can be removed and replaced with an optional video composite unit that will allow transmission of the optical image to a wired or wireless video monitor.
• FIGURE 15-2. Airtraq SP Size 1/Pediatric. This device with the ETT channel accepts tube sizes 4.0 to 5.5.
• FIGURE 15-3. Airtraq Avant including the reusable optic device and the disposable blade and eyepiece.
The Airtraq Avant offers an alternative option with essentially the same operation. The Avant employs a reusable, articulated optic component that is paired with a disposable blade (Fig. 15-3). The optical component has a rechargeable battery with a service life of approximately 100 minutes of continuous on time. This equates to roughly 40 to 50 intubations (Fig. 15-4). The Airtraq SP battery life is approximately 40 minutes, with the shelf life of the self-contained unit being 3 years. The Airtraq Avant reusable optics component is placed in a docking station for charging and storage, where the number of remaining uses is displayed. The display will also show an error code if the optics have become damaged. The Airtraq Avant has two disposable blade sizes that can be used in conjunction with the reusable optics. The blades are size 2 and size 3 and are identical in size to the number 2 and 3 blades of the fully disposable Airtraq SP units. The mouth opening required for both Avant blades is slightly larger at 17 mm.
Operation