Ultrasound protocol in odontogenic infections: a new proposal

Abstract

Background: Point-of-care-ultrasound can be applied to preview a difficult airway, detect the presence of fluid collection, and soft-tissue edema, and guide the drainage location, although is rarely used. The purpose of this study is to validate a protocol for the assessment of these clinical features on patients with severe odontogenic infections.

Material and methods: This was a single-group prospective cohort study (n=20) including patients with the diagnosis of deep-neck propagation of odontogenic infection. A transcervical linear high-frequency probe transducer (13-6 MHz) was used to scan the structures of the upper airway and the infectious collections. The drainage was guided by ultrasound and the patients were daily evaluated, according to the protocol. The data were extracted and the airway volume, midline deviation, and other important data such as length of hospital stay, dysphagia, voice alteration, raised floor of the mouth, dyspnea, and neck swelling were registered.

Results: The ultrasound examination was correlated with multiple clinical findings, such as dyslalia (p=0,069), dysphagia (p=0,028), dyspnea (p=0,001), among others. This protocol has an advantage as it can be used at bedside evaluation, allowing the assessment of severe and unstable patients, and predicting the increase of the hospitalization time (p=0,019).

Conclusions: This protocol is reliable for the assessment of the upper airway, even in an emergency, predicting not only the severity of the clinical features but aids in the determination of the length of the hospitalization time.

Figure 1

A) Ultrasonography image with doppler enhanced study of the carotid bifurcation region revealing the sternocleidomastoid, internal jugular vein, and internal and external carotid. B) Ultrasonography image of the submandibular area, left side normal and right side affected. It is necessary to assess the relationship between the platysma and the adjacent structures. On the affected side, an abscess collection is observed, distorting the local morphology.

Figure 2

A) Ultrasonography image of the sublingual and mylohyoid region revealing the anterior belly of the digastric muscle, mylohyoid muscle, central raphe, genioglossus muscle, and lingual arteries. B) Ultrasonography image of the central cervical area revealing the thyroid cartilage, airway column, and tube placement.

Figure 3

A) Representation of the central neck and upper airway structures, highlighting the area in which the anteroposterior diameter, red arrow, and the laterolateral diameter, green arrow, were measured, at a 20mm height. B) Ultrasonography image of the central cervical area, coming to the airway column deviation by the central raphe of the mylohyoid, not shown on the image and the midline of the airway column. B1- Airway deviation of 3,6mm on the first day of hospitalization. B2- Airway deviation of 0,9mm on the extubation day.

Figure 4

A) Ultrasonography image of the lateral pharyngeal area, left side normal and right side affected. The sternocleidomastoid is the superficial point of this examination, and the pharynx is observed via the airway column shadow. On the affected side, the abscess collection deviates from the airway column and affects the local anatomy. B) 3D-Reproduction of the protocol, illustrating the areas that should be examined.