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Published on: February 27, 2018
A blinded in-vitro study to compare the efficacy of five topical ear drops in clearing grommets blocked with thick
1Department of Otolaryngology, Head and Neck Surgery, York Hospital, York, UK. uppalsandeep@yahoo.com
Objective:
To compare the efficacy of 5% NaHCO3, 3% H2O2, Sofradex (dexamethasone sodium metasulphobenzoate 0.05%, framycetin sulphate 0.5%, gramicidin 0.005%), 0.33% acetic acid and 0.9% NaCl eardrops in clearing grommets blocked with harvested thick middle ear effusion fluid.
Study Design:
A blinded in-vitro study.
Setting:
District general hospital.
Participants:
A total of 473 grommets were blocked with freshly harvested unpooled thick middle ear effusion fluid obtained from 68 patients.
Main Outcome Measures:
Patency of the grommets before and 7 days after intervention was ascertained by tympanometry and close visual inspection.
Results:
Instillation of eardrops leads to a statistically significant increase in the clearance of grommets as compared with not using any drops (chi2 = 14.3, d.f. = 5, P = 0.006). The numbers needed to treat were 2.8 for NaHCO3, 3.2 for 0.9% NaCl, 3.9 for 0.33% acetic Acid, 4.4 for Sofradex and 9.5 for H2O2 eardrops. Pair-wise comparison was only significant for comparison between 5% NaHCO3 and 3% H2O2 eardrops (Bonferroni corrected P = 0.01, odds ratio = 4.3, CI = 1.9-9.9).
Conclusions:
Use of eardrops leads to a clinically and statistically significant increase in the clearance of blocked grommets. Of the five drops used, 5% NaHCO3 was the most efficacious and 3% H2O2 the least efficacious. Limitations of this in-vitro study are recognized and a prospective in-vivo double blind randomized controlled trial is planned.
