title: Pressure regulating ear plug testing in a pressure chamber.
abstract: BACKGROUND
  Middle ear barotrauma is a condition frequently associated with flying. It is usually caused by Eustachian tube (ET) dysfunction. Pressure-regulating earplugs (PREP) should improve complaints due to pressure equalization problems.
  
  
  METHODS
  There were 21 patients with a history of pressure equalization problems while flying who were examined. ET function was measured with exploratory tests and in a pressure chamber. In a double-blind study, PREP were examined using continuous impedance measurement in the pressure chamber. Eardrum deflection and pressure-equalizing maneuvers were also examined. During pressure exposure the subjective state of patients with and without PREP was compared.
  
  
  RESULTS
  Evidence of ET dysfunction was found in twice as many patients with the impedance method in a pressure chamber compared to tympanometry or the Valsalva test. Use of PREP reduced the rate of pressure changes in the external auditory canal. Maximum pressure was reached with a delay of about 7 min. The number of pressure-equalizing maneuvers did not differ significantly. Using PREP the patients reported a significantly better subjective state on the VAS scale of 2.19 +/- 1.50 compared to 3.38 +/- 2.33 without PREP.
  
  
  CONCLUSIONS
  Continuous impedance measurements in the pressure chamber identified ET dysfunction more often than the exploratory ET function tests commonly used in routine diagnostics. This novel finding requires further validation. Although use of PREP showed no signs of improving ET function, it did significantly improve individual subjective state during sudden pressure changes.
authors.affiliation: Department of Otolaryngology, Head & Neck Surgery, Campus Charitn Mitte, Charité-University Medicine Berlin, Germany. masen.jumah@charite.de
authors.forename: Masen Dirk
authors.initials: MD
authors.lastname: Jumah
authors.forename: Miriam
authors.initials: M
authors.lastname: Schlachta
authors.forename: Matthias
authors.initials: M
authors.lastname: Hoelzl
authors.forename: Andreas
authors.initials: A
authors.lastname: Werner
authors.forename: Benedikt
authors.initials: B
authors.lastname: Sedlmaier
mesh_terms: D000158:Acoustic Impedance Tests; D000328:Adult; D000399:Air Pressure; D000401:Aircraft; D001299:Audiometry; D001469:Barotrauma / Q000209:etiology / Q000517:prevention & control*; D004311:Double-Blind Method; D004430:Ear Protective Devices; D004432:Ear, Middle; D005064:Eustachian Tube; D005260:Female; D006801:Humans; D008297:Male; D014636:Valsalva Maneuver