Daily fluctuations of middle ear pressure in atelectatic ears.

The position of the drum of 84 atelectatic ears, of patients 5 to 79 years old, was examined with the help of the operating microscope at different times of the day. All ears were found to be atelectatic during the daytime, yet on the patients' awakening in the morning, 37.73% of the drums of the adolescents' and adults' ears were found to be inflated, usually even hyperinflated. None of the children showed an inflated eardrum in the morning. All eardrums that were inflated in the morning returned to their original atelectatic position within an average of 54.56 minutes after awakening. This observation illustrates another fluctuating aspect of the atelectatic condition.