MIDDLE-EAR GAS-COMPOSITION IN PATHOLOGICAL CONDITIONS - MASS-SPECTROMETRY IN OTITIS-MEDIA WITH EFFUSION AND ATELECTASIS

It is generally assumed that the gas enclosed in the middle ear and ma stoid air cell system is subject to continuous absorption, and that pa rtial pressures for oxygen and carbon dioxide equal those of ''mixed v enous blood.'' We previously determined the concentrations in 10 adult s with healthy ears by means of mass spectrometry. The results showed that the value for oxygen was in the expected range, but that the valu e for carbon dioxide was higher than in ''mixed venous blood.'' The ai m of the present investigation was to measure the gas concentrations w ith the same technique in diseased ears, to see if there are any diffe rences in middle ear gases between healthy and diseased ears. In terms of group means, the present measurements in 13 ears of children with otitis media with effusion or atelectasis did not differ from the valu es previously obtained for healthy ears of adults for any of the gases .