[The function of tubomanometry in forcasting the progonosis of acute otitis media with effusion].

OBJECTIVE

To evaluate the function of tubomanometry (TMM) in forcasting the progonosis of acute otitis media with effusion (OME).

METHOD

We used the technique of TMM to quantify the degree of eustachian tube (ET) dysfunction in 65 patients with OME. The opening of the ET and the transportation of gas into the middle ear were registered by a pressure sensor in the occluded outer ear after applying the stimulus of a controlled gas bolus into the nasopharynx during swallowing. Three excess pressure values were tested subsequently (30, 40, and 50 mbar). If tube opening was registered, the time of opening in relation to pressure applied was measured. The TMM calculated the opening latency index or index R. An R value of < 1 indicated early opening of the tube at the start of application of the stimulus, which was considered optimal. A value > 1 indicated late opening of the tube occurring after the initial stimulus and was interpreted as suboptimal. Inability to calculate the index R value indicated that the tube was unable to actively open at all. The TMM results, were weighted as follows: no R with 0 points, R > 1 with 1 point and R < 1 with 2 points for the measurements at 30, 40, and 50 mbar, respectively. The points of these three tests were added so the ET score (ETS) ranges from 0 (worst value) to 6 (best value). According to the medical history, the patients were divided into two groups, chronic OME group (defined as positive control group), 30 cases with 38 ears; and acute OME group, 35 cases with 46 ears. The healthy ears of all patients were defined as normal control group, 46 cases with 46 ears. The same regular treatments, including classic medical treatments and intratympanic dexamethasone injections, were used to acute OME group in the following 1-2 months. On the basis of therapeutic effect, acute OME group was subdivided into valid group (26 cases with 33 ears) and invalid group (9 cases with 13 ears).

RESULT

The ETS of normal control group was 5.11 ± 1.32 while it was 1.08 ± 1.32 in positive control group. It was found marked differences between the two groups (P < 0.01). The ETS of both valid and invalid subgroup of actue OME group were significantly lower than normal control group (P < 0.01), but in valid subgroup it was significantly higher than positive control group (P < 0.01), and no marked difference was found between the invalid subgroup and positive control group. After treatments, a significant improvement of the ETS was found in both valid and invalid subgroup (P < 0.05) there was no marked difference between valid subgroup and normal control group. But in invalid subgroup it was still significantly lower than normal cohtrol group (P < 0. 01).

CONCLUSION

TMM could forecast the prognosis of acute OME. Patients with acute OME suffered from ET dysfunction of varied degrees. Those with high ETS could be cured by classic medical treatments and intratympanic dexamethasone injections. But those with poor ETS could not be cured in short period, tube insertion should be considered. If ETS could not be improved by ventilation tube placement, more active treatment, for example, balloon Eustachian tuboplasty (BET), should be used to prevent transforming into chronic OME.