Airway control is the first and most critical action of the Emergency Physician. The “A” in the ABC’s demands that no other action may take place until the airway is secure. Endotracheal (ET) intubation inserts an artificial airway connecting the respiratory system to the outside world and provides definitive control of the airway. All methods of support can be applied once the ET tube is in place. Nothing can help the patient if the airway is not secure. ET intubation can be accomplished by a variety of methods. The method of choice will be dictated by physician preference and experience, the patient’s condition, and the available equipment. The most common method of ET intubation is orotracheal intubation. There are no good alternatives to intubation when oxygenation and ventilation are threatened. All actions should be focused on the objectives of getting the ET tube placed quickly and in the right location. The proper preparation, practice, and personnel can assure that the “nightmare airway” is an extremely rare event.1
ANATOMY AND PATHOPHYSIOLOGY
The discussion of anatomy starts at the lips and travels inward to end at the right mainstem bronchus. Visualize the normal structures expected and match them with what is seen as you approach the patient. Distortion occurs from edema or trauma. Structures may be hidden by vomit or blood. Airway structures are viewed upside down from the position of standing over the head of the supine patient. The potential for disorientation is multiplied due to the upside-down view.
Begin at the face and move inward (Figures 18-1 and 18-2). The philtrum of the upper lip will be located at the 6 o’clock (i.e., bottom) position. Symmetrical swelling, carbon deposits, blistering, or signs of trauma to the lips can indicate that the inner anatomy of the airway may be altered and the intubation more difficult. Open the patient’s mouth and check the teeth for fractures, size, and the presence of removable dental devices. Large upper incisors (i.e., buck teeth) and/or limited jaw opening will make orotracheal intubation more difficult. The tongue hangs down from the floor of the mandible and ends with the tip against the maxillary incisors (Figure 18-2). Visualize the tongue as a hanging oval of tissue with two “tips.” The first is the anterior tip of the tongue proper. The second is the posteriorly located epiglottis. The anatomic floor of this view is formed by the hard and soft palates, which end at the palatopharyngeal arch (Figure 18-2). The uvula is located inferiorly and in the midline. The palatoglossal arch and palatopharyngeal arch form twin vertical pillars that lie posterior to the molars of the upper teeth (Figure 18-2). All of these structures are potential sources of obstruction and must be evaluated for swelling, deformity, or trauma. The back wall is the posterior wall of the pharynx (Figure 18-2).