Manometric measurement of Eustachian tube ventilatory function.

Although initial manometric studies of Eustachian tube ventilatory function in both normal and abnormal ears suggested that this technique provided an accurate physiologic assessment of ventilatory function, recent studies have questioned the physiologic nature of these tests. In an effort to clarify this controversy, the tubal ventilatory capacity of 51 ears in which Eustachian tube function was clinically normal was assessed manometrically. Similar measurements were made in 18 ears in which Eustachian tube function was clinically normal except for a complaint of aural fullness. This group showed poorer ventilatory function than normal ears, but the most striking result was the inability of over 50% of the normal group to equilibrate negative pressure to a level within the normal range of 0 to -50 mm H2O. It is postulated that Eustachian tube ventilatory function exhibits a range of individual variability such as is characteristic of other biologic systems.