title: Ototoxic effect of Ultrastop antifog solution applied to the guinea pig middle ear.
abstract: OBJECTIVE
  Recent advances in endoscopic technology have allowed its application to middle ear surgery. An antifog agent is necessary for endoscopy because moisture and blood may obscure visibility. Ultrastop is one of the most commonly used antifog agents. The current study examined the ototoxic effect of topical application of Ultrastop in the guinea pig ear.
  
  
  METHODS
  A preliminary experimental animal study.
  
  
  METHODS
  University hospital.
  
  
  METHODS
  Eighteen male Hartley guinea pigs (weight, 480-620 g) were divided into 3 groups to be treated with Ultrastop, gentamicin (50 mg/mL, positive control), or saline solution (negative control). After auditory brainstem responses were measured, topical solutions of 0.2 mL were applied through a small hole made at the tympanic bulla. Posttreatment auditory brainstem responses were obtained 14 days after the treatment. The extent of middle ear damage was investigated and scored.
  
  
  RESULTS
  The saline-treated group showed no deterioration in auditory brainstem response threshold. The Ultrastop-treated and gentamicin-treated groups showed severe deterioration in auditory brainstem response threshold. Middle ear examination revealed extensive changes in the Ultrastop-treated group and medium changes in the gentamicin-treated group.
  
  
  CONCLUSIONS
  Ultrastop applied topically to the guinea pig middle ear caused significant middle ear inflammation and hearing impairment.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan kazuhiroe@gmail.com.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Nomura
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Oshima
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Yamauchi
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Hidaka
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.
authors.forename: Tetsuaki
authors.initials: T
authors.lastname: Kawase
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Katori
mesh_terms: D000818:Animals; D004432:Ear, Middle / Q000187:drug effects*; D000431:Ethanol / Q000009:adverse effects*; D016057:Evoked Potentials, Auditory, Brain Stem / Q000187:drug effects; D006168:Guinea Pigs; D034381:Hearing Loss / Q000139:chemically induced*; D008297:Male; D012996:Solutions; D013501:Surface-Active Agents / Q000009:adverse effects*
chemical_list: D012996:Solutions; D013501:Surface-Active Agents; D000431:Ethanol
keywords: endoscope; endoscopic ear surgery; ethanol; hearing; inflammation