Dynamic behavior of the oropharynx airway during deep breath in patients with obstructive sleep apnoea hypopnoea syndrome observed by ultrasonography

Abstract

This study aimed to determine whether ultrasonography can be used to assess the oropharyngeal airway in patients with obstructive sleep apnoea hypopnoea syndrome (OSAHS). 104 patients with OSAHS and 104 sex-, body mass index (BMI)-, and age-matched healthy subjects underwent oropharynx airway assessment using ultrasound. The dimensional changes of the oropharynx were monitored, and sonographic measurements of the airway lumen were obtained during deep breathing. Measurements were compared between groups. All suspected patients underwent Polysomnography in the sleep laboratory. OSAHS was defined as apnea-hypopnea index (AHI) > 5 events/h. Adequate visualization of oropharyngeal dimensional changes was obtained in 95.19% of patients with OSAHS and 100% of healthy subjects. The anteroposterior diameter (AP) and lateral diameter (LAT) of the oropharyngeal airway of patients with OSAHS were smaller than those of healthy subjects at the end of deep inspiration and expiration (all P < 0.05). Patients with OSAHS had greater lateral airway dimensional changes than the anterior-posterior dimension changes (P < 0.001). The AP/LAT ratio of OSAHS at the end of deep inspiration was higher than that of healthy subjects (P = 0.012). Ultrasonography can detect the dimensional changes of the oropharyngeal airway in patients with OASHS during deep breathing. Patients with OASHS have a smaller airway size, a more circular configuration, and a more significant change of diameter in oropharynx airway than healthy subjects.

Keywords: Deep breath; Dynamic behavior; OSAHS; Oropharynx airway; Ultrasonography.

Fig. 1

Probe location in lateral oblique planes.

Fig. 2

Probe location in transverse planes.

Fig. 3

The displacement of tissues during deep breathing in patients with OSAHS in lateral oblique views. (a) Probe location in lateral oblique planes. (b) Sonogram of the oropharynx in patients with OSAHS at the end of deep inspiration. (c) Sonogram of the oropharynx in patients with OSAHS at the end of deep expiration. Lateral oblique images taken in the submandibular region show an oropharynx airway, which appears hyperechoic curvilinear line (small arrows). Hyperechoic echogenicity with ringdown gas artifact (large arrows) suggests the airway origin. 1 and 2, the caliper points show the borders of the airway, and the anterior-posterior diameter (between cursors) of the oropharynx airway was measured in these standard planes. GG indicates genioglossus. (d) Schematic drawing of the internal anatomy of the oropharynx, the transducer position, and illustration of ultrasonic measurements.

Fig. 4

The displacement of tissues during deep breathing healthy subjects in lateral oblique views. (a) Probe location in lateral oblique planes. (b) Sonogram of the oropharynx in healthy subjects at the end of deep inspiration. (c) Sonogram of the oropharynx in healthy subjects at the end of deep expiration. Lateral oblique images taken in the submandibular region show the oropharynx airway, which appears hyperechoic curvilinear line (small arrows). 1 and 2, the caliper points show the borders of the airway, and the anterior-posterior diameter (between cursors) of the oropharynx airway was measured in these standard planes. GG indicates genioglossus. (d) Schematic drawing of the internal anatomy of the oropharynx, the transducer position, and illustration of ultrasonic measurements.

Fig. 5

The displacement of these tissues during deep breathing in healthy subjects in transverse views. (a) Probe location in transverse planes. (b) Sonogram of the oropharynx in healthy subjects at the end of deep inspiration. (c) Sonogram of the oropharynx at the end of deep expiration. A transverse view of the oropharynx airway taken with the probe in the submental area just above the hyoid bone shows the oropharynx airway (arrows) as a bright hyperechoic line. The anterior and lateral walls of the oropharynx airway are formed by the genioglossus (GG) and lateral oropharyngeal wall (triangle), respectively. The lateral diameter (cursors and the number 1,2) of the oropharynx airway was measured in these standard planes. MH indicates mylohyoid; GH, geniohyoid. (d) Schematic drawing of the internal anatomy of the oropharynx, the transducer position, and illustration of ultrasonic measurements.

Fig. 6

The displacement of these tissues during deep breathing in patients with OSAHS in transverse views. (a) Probe location in transverse planes. (b) Sonogram of the oropharynx in healthy subjects at the end of deep expiration. (c) Sonogram of the oropharynx at the end of deep inspiration. A transverse view of the oropharynx airway taken with the probe in the submental area just above the hyoid bone shows the oropharynx airway (arrows) as a bright hyperechoic line. The anterior and lateral walls of the oropharynx airway are formed by the genioglossus (GG) and lateral oropharyngeal wall (triangle), respectively. The lateral diameter (cursors and the number 1,2) of the oropharynx airway was measured in these standard planes. MH indicates mylohyoid; GH, geniohyoid. (d) Schematic drawing of the internal anatomy of the oropharynx, the transducer position, and illustration of ultrasonic measurements.

Fig. 7

ROC curve of ultrasound quantitative parameters.

Fig. 8

Sonogram of the oropharynx in patients with OSAHS. (a) Sonogram of the oropharynx in patients with OSAHS at the end of deep inspiration. (b) Sonogram of the oropharynx in patients with OSAHS at the end of deep expiration. Transverse view of the oropharynx airway in a 37-year-old patient with OSAHS (male; BMI, 34.54; AHI, 107/h; LSAT, 44%) with the probe placed just above the hyoid bone. GG indicates genioglossus; MH, mylohyoid; and GH, geniohyoid.