title: Characterizing the active opening of the eustachian tube in a hypobaric/hyperbaric pressure chamber.
abstract: OBJECTIVE
  Active and passive opening of the Eustachian tube (ET) enables direct aeration of the middle ear and a pressure balance between middle ear and the ambient pressure. The aim of this study was to characterize standard values for the opening pressure (ETOP), the opening frequency (ETOF), and the opening duration (ETOD) for active tubal openings (Valsalva maneuver, swallowing) in healthy participants.
  
  
  METHODS
  In a hypobaric/hyperbaric pressure chamber, 30 healthy participants (19 women, 11 men; mean age, 25.57 ± 3.33 years) were exposed to a standardized profile of compression and decompression. The pressure values were recorded via continuous impedance measurement during the Valsalva maneuver and swallowing. Based on the data, standard curves were identified and the ETOP, ETOD, and ETOF were determined.
  
  
  RESULTS
  Recurring patterns of the pressure curve during active tube opening for the Valsalva maneuver and for active swallowing were characterized. The mean value for the Valsalva maneuver for ETOP was 41.21 ± 17.38 mbar; for the ETOD, it was 2.65 ± 1.87 seconds. In the active pressure compensation by swallowing, the mean value for the ETOP was 29.91 ± 13.07 mbar; and for the ETOD, it was 0.82 ± 0.53 seconds.
  
  
  CONCLUSIONS
  Standard values for the opening pressure of the tube and the tube opening duration for active tubal openings (Valsalva maneuver, swallowing) were described, and typical curve gradients for healthy subjects could be shown. This is another step toward analyzing the function of the tube in compression and decompression.
authors.affiliation: *University of Cologne, Department of Otorhinolaryngology, Head and Neck Surgery; †University of Cologne, Institute of Medical Statistics, Informatics and Epidemiology; and ‡Hospital "Schwarzwald-Baar Klinikum," Department of Otorhinolaryngology, Villingen-Schwenningen, Germany.
authors.forename: Stefanie
authors.initials: S
authors.lastname: Mikolajczak
authors.forename: Moritz Friedo
authors.initials: MF
authors.lastname: Meyer
authors.forename: Moritz
authors.initials: M
authors.lastname: Hahn
authors.forename: Christine
authors.initials: C
authors.lastname: Korthäuer
authors.forename: Masen Dirk
authors.initials: MD
authors.lastname: Jumah
authors.forename: Karl-Bernd
authors.initials: KB
authors.lastname: Hüttenbrink
authors.forename: Maria
authors.initials: M
authors.lastname: Grosheva
authors.forename: Jan Christoffer
authors.initials: JC
authors.lastname: Luers
authors.forename: Dirk
authors.initials: D
authors.lastname: Beutner
mesh_terms: D000328:Adult; D000399:Air Pressure; D003679:Deglutition / Q000502:physiology; D005064:Eustachian Tube / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D014636:Valsalva Maneuver / Q000502:physiology; D055815:Young Adult