Test-retest validity of acoustic pharyngometry measurements

Acoustic reflectometry is a relatively new technique that quantifies upper airway obstruction. The oropharyngeal airway is geometrically complex and variable; therefore establishing a standard operating protocol and understanding the possible sources of artifacts are of great importance in obtaining reliable results. This work aims at assessing the repeatability of pharyngeal cross-sectional area measurements obtained from normal and snoring individuals.

Twenty adult normal volunteers (16 men and 4 women; mean age, 35.9 years) and 10 adult snorers (9 men and 1 woman; mean age, 36.4 years) were examined by acoustic reflectometry following the developed standard operating protocol.

Measurements of pharyngeal cross-sectional area are analyzed in 2 groups. In normal subjects where mean pharyngeal cross-sectional area in the first session was 3.187 cm(2), in the second session (same-day test-retest), the mean pharyngeal cross-sectional area was 3.239 cm(2), and in the third session 7 to 10 days later (day-to-day test-retest), it was 3.245 cm(2) (P > 0.4). In a second group of snoring patients where mean pharyngeal cross-sectional area in the first session was 2.244 cm(2), in the second session, mean pharyngeal cross-sectional area was 2.237 cm(2), and mean pharyngeal cross-sectional area in the third session (7 to 10 days later) was 2.238 cm(2) (P > 0.9).

These results show that repeatability of acoustic reflection results can be achieved following the standard operating protocol.

The study results add to the reliability of this technique in assessing the pharyngeal airway in patients with snoring and obstructive sleep apnea.