Short of Breath position is even more exaggerated when the head is flexed. Therefore, with a simple technique the airway can be reopened. This so-called headtilt/chin-lift (Fig. 1.5) tilts the head backward to what is often called the "sniffing position." In this position, the trachea and pharynx angulation is minimal, allowing for air transport. Also, the index and middle fingers of the examiner's hand lift the mandible and bring the tongue forward. Another technique is the so-called jawthrust/head-tilt. The examiner places the ring, middle, and little fingers underneath the patient's jaw and lifts the chin forward. The examiner's index finger and thumb are free to fit a mask snugly to the face, with the other hand free to operate a resuscitation bag. When the airway appears blocked by foreign material or dentures, this technique is modified by placing the thumb in the mouth, grasping the chin, and pulling it upward, leaving the other hand to clear any obstructing material from the airway (Fig. 1.5). An oropharyngeal airway should be placed and is essential in patients who recently had a seizure because it prevents further tongue biting. The placement of this oral airway device is simple. The mouth is opened, a wooden tongue depressor is placed at the base of the tongue, and downward pressure is applied to displace the tongue from the posterior pharyngeal wall. The oropharyngeal tube is then placed close to the posterior wall of the oropharynx and is moved toward the tongue until the teeth are at the bite-block section. Alternatively, the jaw is thrust forward and the device is placed concave toward the palate and then rotated.18 Dental injury, most commonly in patients who have significant dental or periodontal disease, rarely occurs. Jaw thrust and mask ventilation securely maintain an open airway but must be followed by endotracheal intubation done by an experienced physician. Endotracheal intubation may be complicated in a traumatized patient with possible cervical spine injury. The ideal solution in these patients is to use fiberoptic bronchoscopy because with this procedure the risk of further neck trauma from neck movement is very low. Immediate endotracheal intubation is required in patients with penetrating neck trauma or significant intraoral bleeding. Temporarily, a cricothyrotomy can be made. A 14-gauge needle is inserted
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through the cricothyroid membrane, followed by insertion of a cannula. (The cricothyroid membrane is located just under the thyroid.) A formal tracheostomy should follow because ventilation through this small, highly flow-resistant tube is compromised. Hypoxemia is often encountered, and oxygen administration has a high priority in patients with impaired consciousness. Nasal prongs are inefficient because they provide only 30% oxygen concentrations and often dislodge. Nasopharyngeal catheters provide 60% oxygen concentrations (but
Figure 1.5 Techniques of airway management. A, Tongue jaw lift/finger sweep. B, Head tilt/chin lift. C, Jaw thrust/mask ventilation. From Wijdicks EFM, Borel CO.18 By permission of Mayo Foundation.