Gas absorption in serous otitis. A clinical aspect.

Animal experiments have shown that gas absorption can produce a considerable intratympanic underpressure when the gas composition of the middle ear is disturbed. A similar phenomenon was observed in children with serous otitis. In 12 ears with underpressures exceeding -150 mm H2O, Valsalva inflation or politzerization produced a transient improvement followed by a rapid return to subatmospheric pressures ranging from -130 to -300 mm H2O. In four cases with middle ear pressures between -65 and -135 mm H2O, the same procedure did not result in any significant underpressures. These findings suggest that inflation of the middle ear in the presence of a deep underpressure serves no purpose. It is also possible that a negative pressure, once established, can be maintained in this way.