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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.