Sonotubometry: a useful tool to measure intra-individual changes in eustachian tube ventilatory function.

To determine whether intra-individual changes in eustachian tube (ET) function induced by local application of a histamine phosphate solution can be detected using an improved sonotubometer. The function of the ET was measured with a revised sonotubometer before and after histamine was applied to the nasopharyngeal ostium of the ET. Tertiary referral hospital. Twenty-five otologically healthy adults. A histamine phosphate solution with a concentration of 16 mg/mL was applied to the nasopharyngeal ostium of the ET using a pressure nebulizer. The number of openings during 10 acts of swallowing. This outcome value could range from 0 to 10. The number of ET openings before and after histamine application was compared. The mean number of ET openings dropped dramatically: from 8.4 before application of histamine to 2.7 after application. This difference was statistically significant; there was a mean difference of 5.6 (95% confidence interval, 4.4-6.9; P < .001). Sonotubometry is capable of detecting intra-individual changes in ET function and may therefore be a very useful tool in monitoring and/or clinical research of ET dysfunction or function.