Middle ear total pressure measurement as a useful parameter for outcome prediction in pediatric otitis media with effusion.

OBJECTIVE

For the effective treatment of pediatric otitis media with effusion (OME) with a ventilation tube, routine evaluation of the condition of the middle ear mucosa after tube placement is critical. For this purpose, we monitored the changes in the middle ear total pressure (METP) associated with the transmucosal gas exchanges. We also evaluated the function of the eustachian tube by sonotubometry. The present study aimed to examine the temporal changes in the maximum METP after tube placement and to assess the association between the maximum METP and subsequent outcome. We also investigated the predictive value of METP measurement and sonotubometry on tube removal.

METHODS

To study the temporal changes in the maximum METP after tube placement and the association between the maximum METP and outcome after tube removal, 78 patients were enrolled, who underwent ventilation tube placement between April 1991 and May 2002 and were followed up for at least a year after tube removal. Of these 78 patients, 54 patients who underwent the METP measurement on tube removal and 39 patients who underwent sonotubometry on tube removal were included in a retrospective analysis of the predictive value of these tests. The patients were divided into 4 groups according to the outcome after tube removal, graded as "excellent", "good", "persistent perforation" and "recurrence".

RESULTS

The maximum METP exhibited a tendency to increase after 18 months or longer of tube placement. The comparisons of the maximum METP across the patient groups revealed that the maximum METP in patients with "excellent" was significantly higher than that in patients with "recurrence" (Student's t-test, P<0.05). As for the prediction of outcomes on tube removal, 32.4 and 57.1% of patients were predicted to have a good outcome by sonotubometry and the METP measurement, respectively (chi2 test, P<0.05). Among patients with a maximum METP higher than 31 mm H2O, 93.3% exhibited no recurrence after tube removal.

CONCLUSIONS

Favorable outcome after tube removal was associated with more active transmucosal gas exchange. The maximum METP best reflected the outcome after tube removal, indicating a superior predictive value of the METP measurement over sonotubometry.