Point-of-care ultrasound for airway management in the emergency and critical care setting

Abstract

Airway management is a common procedure within emergency and critical care medicine. Traditional techniques for predicting and managing a difficult airway each have important limitations. As the field has evolved, point-of-care ultrasound has been increasingly utilized for this application. Several measures can be used to sonographically predict a difficult airway, including skin to epiglottis, hyomental distance, and tongue thickness. Ultrasound can also be used to confirm endotracheal tube intubation and assess endotracheal tube depth. Ultrasound is superior to the landmark-based approach for locating the cricothyroid membrane, particularly in patients with difficult anatomy. Finally, we provide an algorithm for using ultrasound to manage the crashing patient on mechanical ventilation. After reading this article, readers will have an enhanced understanding of the role of ultrasound in airway management.

Keywords: Airway management; Intubation; Ultrasonography; Ultrasound.

Fig. 1.

Distance from the skin to the epiglottis. Example measurement from skin to anterior aspect of the epiglottis (star).

Fig. 2.

Distance from the skin to the vocal cords. Example measurement from skin to anterior aspect of the vocal cords. The arrow indicates the anterior vocal cord commissure.

Fig. 3.

Hyomental distance. Example measurement of hyomental distance. The arrow indicates the mentum. The star indicates the hyoid.

Fig. 4.

Tongue thickness. Example measurement from skin to posterior aspect of the tongue (star).

Fig. 5.

Difficult Airway Evaluation with Sonography (DARES) algorithm. DSE, distance from the skin to the epiglottis; HMD, hyomental distance; TT, tongue thickness; HMDR2, ratio of the HMD measured with the head in maximal extension and the head in neutral position; HMDR1, ratio of the HMD measured with the head in a ramped position and the head in neutral position. Adapted from Lin et al. [21], available under the Creative Commons License.

Fig. 6.

Tracheal intubation. The arrow indicates the anterior aspect of endotracheal tube. T, trachea.

Fig. 7.

Esophageal intubation. In the case of esophageal intubation, a curvilinear structure which mimics the trachea (T), is seen to the right of the trachea. This is the endotracheal tube within the esophagus (E).

Fig. 8.

Endotracheal tube in the correct depth. The star indicates the cricoid cartilage. The arrow indicates the endotracheal tube cuff.

Fig. 9.

Cricothyroid membrane. The arrowhead indicates the thyroid cartilage. The arrow indicates the cricothyroid membrane. The star indicates the cricoid cartilage.