Per-operative antibiotic/steroid prophylaxis of tympanostomy tube otorrhoea: chemical or mechanical effect?

The per-operative instillation of ototopical antibiotic/steroid drops reduces the incidence of early otorrhoea after tympanostomy tube insertion. Whether this is due to the chemical properties of the antibiotic/steroid or simply the mechanical instillation of fluid is unclear. In this paired matched study of 161 subjects Gentisone HC was shown to significantly reduce the otorrhoea rate compared to normal saline (1.24 per cent compared with 9.32 per cent, p < 0.005, difference 8.07 per cent, 95 per cent confidence interval for difference 3.21 per cent to 12.93 per cent). Capillary viscosimetry proved Gentisone HC to be more viscous than normal saline. The benefits are due to Gentisone HC's chemical properties, and Gentisone HC rather than normal saline instillation per-operatively is recommended when tympanostomy tubes are inserted.