Tympanostomy tubes and liquids--an in vitro study.

Placement of tympanostomy tubes is the most frequently performed otolaryngologic procedure. The common practice is to forbid swimming and to recommend limitation of liquids entering the external auditory canal based upon the premise that liquids entering the external auditory canal will pass freely into the middle ear space via the tube and thus contaminate the space. Indeed, otologic medications (drops) are presumed and are observed to enter the middle ear space by this same route. The physical characteristics of the middle ear and drumhead with a tube in place were examined and a model constructed to test by observation these characteristics. Measurements of the surface tension of water, 2N saline, Cortisporin suspension ear drops, and soapy bath water were performed to provide a clinical correlate. The study implies that limitation of swimming activities or liquid exposure of the ear with a tympanostomy tube in all children may be inappropriate.