title: A blinded in-vitro study to compare the efficacy of five topical ear drops in clearing grommets blocked with thick middle ear effusion fluid.
abstract: 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.
  
  
  METHODS
  A blinded in-vitro study.
  
  
  METHODS
  District general hospital.
  
  
  METHODS
  A total of 473 grommets were blocked with freshly harvested unpooled thick middle ear effusion fluid obtained from 68 patients.
  
  
  METHODS
  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.
authors.affiliation: Department of Otolaryngology, Head and Neck Surgery, York Hospital, York, UK. uppalsandeep@yahoo.com
authors.forename: S
authors.initials: S
authors.lastname: Uppal
authors.forename: R
authors.initials: R
authors.lastname: Sharma
authors.forename: S K
authors.initials: SK
authors.lastname: Nadig
authors.forename: G
authors.initials: G
authors.lastname: Back
authors.forename: R J A
authors.initials: RJ
authors.lastname: England
authors.forename: A P
authors.initials: AP
authors.lastname: Coatesworth
mesh_terms: D019342:Acetic Acid / Q000008:administration & dosage / Q000627:therapeutic use; D000158:Acoustic Impedance Tests; D000287:Administration, Topical; D000293:Adolescent; D000328:Adult; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D003907:Dexamethasone / Q000008:administration & dosage / Q000627:therapeutic use; D004338:Drug Combinations; D005260:Female; D005601:Framycetin / Q000008:administration & dosage / Q000627:therapeutic use; D006096:Gramicidin / Q000008:administration & dosage / Q000627:therapeutic use; D006801:Humans; D066298:In Vitro Techniques; D007223:Infant; D008297:Male; D008875:Middle Aged; D008876:Middle Ear Ventilation / Q000295:instrumentation; D010034:Otitis Media with Effusion / Q000188:drug therapy* / Q000628:therapy; D019999:Pharmaceutical Solutions / Q000008:administration & dosage / Q000627:therapeutic use*; D017693:Sodium Bicarbonate / Q000008:administration & dosage / Q000627:therapeutic use; D012965:Sodium Chloride / Q000008:administration & dosage / Q000627:therapeutic use
chemical_list: D000893:Anti-Inflammatory Agents; D004338:Drug Combinations; D019999:Pharmaceutical Solutions; D006096:Gramicidin; D012965:Sodium Chloride; D005601:Framycetin; C023881:Sofradex; D003907:Dexamethasone; D017693:Sodium Bicarbonate; D019342:Acetic Acid