Abstract
Eustachian tube function was tested by sonotubometry in 25 adult, otologically healthy males in different body positions(sitting, supine, prone, rt. lateral, lt. lateral, and-90° head down).
To evaluate the ability of the Eustachian tube to open actively, we recorded the duration of tube patency and the sound pressure change with swallowing.
To evaluate passive opening function of the Eustachian tube, we recorded the increased pressure level in the nasal cavity by Valsalva's maneuvre forcing the Eustachian tube to open passively.
Eustachian tube patency was less in the horizontal and head down positions than in the sitting position.
Significant differences between sitting and horizontal positions, and between horizontal and head down positions were found in the duration of tube patency with swallowing and in the opening pressure level with Valsalva's maneuvre. No significant change was found in the sound pressure change with swallowing.
It seems that one of the factors causing the postural effect on Eustachian tube function might be increased venous pressure.
