OBJECTIVETo study the relationship between the fibrinogen content in middle ear effusion (MEE) and the protracted inflammation of secretory otitis media (SOM) and to explore the possible mechanism of batroxobin in treatment of SOM.

METHODSThe fibrinogen content of middle ear effusion from 156 patients with SOM was investigated with concretion technique at different stages. After two times punctuation of tympanum, the recurrence patients were randomly divided into two groups: batroxobin and dexamethasone group, and 0.5 ml (2 BU/ml) batroxobin or dexamethasone (2 mg/ml) was injected into middle ear cavity. The therapeutic effects were investigated.

RESULTSThe concentration of fibrinogen in the recurrence group of SOM patients was higher than that in the cured group, and even higher in the second recurrence group than in the first recurrence group (P < 0.01). There was significantly different (P < 0.001) in the therapeutic efficacy between the batroxobin group (91.6%) and the dexamethasone group (62. 5%); the difference of the fibrinogen content in MEE and air conduction of pure tone audiometry at frequencies (0.5, 1.0, 2.0 kHz) between the two groups after treatment were also significant (P < 0.01).

CONCLUSIONSFibrinogen may play a significant role in the occurrence and development of secretory otitis media. Batroxobin had better therapeutic effect on SOM than dexamethasone. The mechanism of batroxobin in the treatment of SOM may be that the batroxobin can relief the depressant effect of fibrinogen on surface active agents of the Eustachian tube and prevent the fibrinogen from turning into insoluble fibrin polymer by means of fibrinolysis.