technique may be similar to or different from direct laryngoscopy, depending on the specific device. For example, the video laryngoscope blade may be similar to a Macintosh blade, requiring the same approach. In that case, the real‐time advantages of video laryngoscopy are the enhanced perspective and views of airway anatomy and abilities of others to see what the principal operator sees, better enabling them to be helpful. Some video laryngoscopes include angulated blades. Instead of facilitating alignment of airway structures to provide direct visualization, angulated blades follow the resting anatomic contour of the oropharynx to the glottis (Figure 3.4). The patient’s tongue is not manipulated as it is for direct laryngoscopy, and less patient movement or repositioning may be required. A special stylet for the endotracheal tube is generally necessary so that the angle of the blade can be followed. Some curved blades incorporate an integrated channel to direct the endotracheal tube, obviating the need for a stylet.
Figure 3.4 GlideScopeTM video laryngoscope
Nasotracheal intubation
Nasotracheal intubation involves insertion of an endotracheal tube through the nose and into the trachea. It is possible only on patients with intact respiratory efforts: for example, individuals with congestive heart failure or acute pulmonary edema. The approach may be possible for patients who cannot lay supine: for example, patients entrapped after a motor vehicle collision. In contrast with orotracheal methods, nasotracheal intubation is often possible in awake patients and those with intact gag reflexes or trismus.
Successful nasotracheal intubation requires a skilled and experienced operator. The rescuer chooses an endotracheal tube one‐half size smaller than customary for orotracheal intubation, inserting the tube into the nares without a stylet, and directing the endotracheal tube inferiorly and anteriorly toward the vocal cords. We recommend first entering the right nostril, which is often larger than the left nostril. The rescuer coordinates insertion of the tube through the vocal cords with patient inhalation. The nasal passage may be dilated by initially inserting a nasal airway for several minutes prior to attempting tracheal tube placement. The nasal airway is then removed prior to placing the tube.
The Endotrol endotracheal tube has a special trigger device that provides directional control of the tip, flexing it to facilitate its correct trajectory toward the larynx as the tube is advanced [32]. A potentially helpful adjunct is the Beck Airway Airflow Monitor (BAAM®; Great Plains Ballistics, Lubbock, Texas). When placed on the connector end of the endotracheal tube, the device “whistles” as air is exhaled though the endotracheal tube approaching vocal cords. Important complications associated with nasotracheal intubation include nasal trauma and epistaxis, sinusitis (which may cause sepsis), and perforation of the cribiform plate with subsequent intracranial placement [33–37].
Other intubation techniques
Digital intubation is one of the original methods of endotracheal intubation [38]. For this procedure, the rescuer places his or her second and third fingers into the patient’s pharynx, forming a cradle extending to the epiglottis and the vocal cords. The rescuer then uses the other hand to guide an endotracheal tube along the cradle and through the vocal cords. Some clinicians recommend twisting the endotracheal tube into a corkscrew shape to facilitate the technique (Figure 3.5). Digital intubation may be a useful approach to an unresponsive patient where EMS personnel have limited access to the airway. The technique could result in rescuer injury should the patient bite down during the procedure [39]. A dental prod or bite block will minimize this risk.
Figure 3.5 Corkscrew of endotracheal tube for digital intubation
A lighted stylet is a semirigid stylet equipped with a battery‐powered lighted tip [39]. The rescuer inserts the stylet through the endotracheal tube and bends the combination into a “hockey stick” shape. The rescuer then inserts the stylet/endotracheal tube combination blindly into the oropharynx and uses the light to facilitate movement of the tube through the vocal cords. When properly placed, the illumination bulb of the lighted stylet is visible through the patient’s cricoid membrane. Few EMS agencies use lighted stylet intubation due to the cost of the device and difficulty of the technique. Furthermore, the procedure is limited by the need for low ambient lighting.
In retrograde intubation, the rescuer places a large‐bore needle through the cricothyroid membrane, pointing it cephalad, and then inserts a guidewire through the needle, advancing it superiorly until the wire tip comes out through the mouth. A conventional endotracheal tube can then be threaded over the guidewire and through the vocal cords. It is important that the wire be threaded through the “Murphy’s eye” of the tube. Commercial kits exist for retrograde intubation. Only limited data support this technique in the prehospital environment [40].
The Gum elastic bougie, an adjunct for orotracheal intubation, is essentially a semirigid stylet (Figure 3.6). The rescuer performs conventional orotracheal laryngoscopy, placing the bougie through the vocal cords and into the trachea. Because the bougie is smaller and stiffer than an endotracheal tube, it is usually easier to place through the vocal cords. The angled, “hockey stick” tip also provides tactile feedback from the tracheal rings, assuring that the device is in the correct endotracheal position. The rescuer can then slide a conventional endotracheal tube over the bougie and through the vocal cords before removing the bougie. The bougie can also be used as a “tube changer” in the event of balloon rupture, clogging of the tube with vomitus, or other problems. A randomized trial found higher first‐pass ETI success with bougie use during emergency department rapid sequence intubations [41]. Limited data describe improved ETI success with bougie use in prehospital intubations [42, 43].
Figure 3.6 Gum elastic bougie threaded into an endotracheal tube. The bougie is often placed in the trachea with direct laryngoscopy first and the endotracheal tube then threaded over it.
Supraglottic airways
SGAs are advanced airway devices used to facilitate ventilation without conventional endotracheal tubes [44]. Other terms commonly used to describe SGAs include “extraglottic airway,” “rescue airway,” “secondary airway,” “failed airway device,” “difficult airway device,” “salvage airway,” “alternate airway,” and “backup airway.” In current prehospital practice, EMS personnel typically reserve SGAs use for situations with failed ETI efforts, but recent reports suggest a potential primary role for SGAs, especially in the setting of cardiac arrest [45, 46]. The most common SGAs in current North American prehospital use are the i‐gel™, the laryngeal tube (LT) airway, and the Laryngeal Mask Airway (LMA™). When EMS personnel have inserted an SGA instead of endotracheal tube, they should provide advance notification to the receiving ED since the SGA may require exchange to an endotracheal tube or surgical airway, and the receiving ED may need additional time to prepare or to assemble an appropriate team [47].
i‐gel
The i‐gel (Intersurgical, Inc., Liverpool, NY) (Figure 3.7) is a single