title: Effect of positional change and inhalant anesthesia on parameters of acoustic reflectometry.
abstract: OBJECTIVE
  Purpose of this study was to find out the effect of positional change and inhalant anesthesia on acoustic reflectometry (AR) parameters (reflectivity and curve angle).
  
  
  METHODS
  AR parameters were measured on 58 ears with otitis media in sitting position before anesthesia and in supine position under inhalant anesthesia, subsequently.
  
  
  RESULTS
  Under anesthesia, ears with effusion disclosed more changes in reflectivity (Chi-squared analysis, chi2-test; P<0.05) and curve angle (P>0.1) than those without effusion. Further, inhalant anesthesia caused more changes in the false negative ears (63.63%) than in those with effusion having positive test before anesthesia (12.90%) (P<0.001).
  
  
  CONCLUSIONS
  From the data of this study, it could be said that reflectivity shows changes according to the amount of effusion which is in contact with the tympanic membrane under anesthesia, and that curve angle becomes more sensitive to detect effusion when anesthetic gas diffuses into the middle ear with effusion, probably due to the pushing of effusion towards the tympanic membrane.
authors.affiliation: Department of ENT-HNS, Faculty of Medicine, Gazi University, Ankara, Turkey.
authors.forename: M B
authors.initials: MB
authors.lastname: Uğur
authors.forename: Yusuf K
authors.initials: YK
authors.lastname: Kemaloğlu
authors.forename: A
authors.initials: A
authors.lastname: Ceylan
authors.forename: S
authors.initials: S
authors.lastname: Boynueğri
authors.forename: A
authors.initials: A
authors.lastname: Babacan
authors.forename: N
authors.initials: N
authors.lastname: Gŏksu
mesh_terms: D000769:Anesthesia, Inhalation; D018685:Anesthetics, Inhalation / Q000494:pharmacology; D002648:Child; D002675:Child, Preschool; D004432:Ear, Middle / Q000187:drug effects*; D005260:Female; D006801:Humans; D008297:Male; D009609:Nitrous Oxide / Q000494:pharmacology; D010034:Otitis Media with Effusion / Q000175:diagnosis* / Q000503:physiopathology; D011187:Posture; D012022:Reflex, Acoustic; D012680:Sensitivity and Specificity; D014432:Tympanic Membrane / Q000187:drug effects*
chemical_list: D018685:Anesthetics, Inhalation; D009609:Nitrous Oxide