What is the term for when it becomes impossible to open the Eustachian tube due to pressure differential exceeding 80 mmHg?

The term that specifically refers to the inability to open the Eustachian tube due to a significant pressure differential, such as exceeding 80 mmHg, is known as "pressure equalization failure." This condition occurs when the pressure in the middle ear cannot adjust to changes in ambient pressure, leading to discomfort and potential injury. The Eustachian tube normally allows air to flow between the middle ear and the nasopharynx, equalizing pressure; however, when the pressure differential becomes too high, this tube can become functionally blocked, preventing equalization.

In aviation and other environments where rapid altitude changes occur, pressure equalization failure can lead to barotrauma, where the pressure differences cause physical damage to the ear structures. Understanding this term is crucial for recognizing the physiological challenges associated with rapid ascent and descent in altitude.