Reliability of Eustachian tube function measurements in a hypobaric and hyperbaric pressure chamber

Meyer, Moritz; Jansen, Stefanie; Mordkovich, Oxana; Hüttenbrink, Karl-Bernd; Beutner, Dirk

doi:10.1111/coa.12884

Cited by 8 publications

(8 citation statements)

References 18 publications

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“…A shorter Eustachian tube opening and less possibility of pressure equalization by Toynbee in comparison to the Frenzel maneuver seems logical and was thus presumed. Fittingly, the pressure curve during the Frenzel maneuver is reminiscent of pressure curves during the Valsalva maneuver [8,9]. However, the comparison of ETOP between Frenzel and Valsalva revealed a significantly higher ETOP for the Valsalva maneuver.…”

Section: Discussionmentioning

confidence: 99%

“…1 and supplementary Fig. 1) [8,9]. Continuous impedance measurements (tympanometry) were performed via an ear probe containing a miniature loudspeaker, microphone and a small tube to allow pressure equalization between the ear canal and the chamber pressure environment.…”

Section: Pressure Chamber Profilementioning

confidence: 99%

“…ETOD defines the time span between opening and closing of the ET. Evaluation of the ET parameters in detail are demonstrated in previously published articles [8,9,12,13].…”

Section: Eustachian Tube Function Parametermentioning

confidence: 99%

“…Therefore such studies pose an objective and reliable method to characterize the Frenzel maneuver for the first time [8]. By means of an established standardized profile of compression and decompression in a hypo/ hyperbaric pressure chamber different parameters such as the ET opening pressure (ETOP), ET opening duration (ETOD), and ET opening frequency (ETOF) can be evaluated and describe the dynamic function of the Eustachian tube [9].…”

Section: Introductionmentioning

confidence: 99%

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Prospective study on the Eustachian tube function during Frenzel maneuver in a hypobaric/hyperbaric pressure chamber

Wolber

Meyer

Knesic

et al. 2021

Eur Arch Otorhinolaryngol

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Introduction The Frenzel maneuver describes a technique for middle ear equalizing which is frequently used by apnea divers. It offers advantages compared to the most commonly used techniques such as the Valsalva or Toynbee maneuver. Until now, there is insufficient literature about the pressure dynamics and Eustachian tube (ET) function during the Frenzel maneuver. The aim of the present study was to characterize the ET function during the Frenzel maneuver. Materials and methods By means of an established standardized profile of compression and decompression in a hypo/hyperbaric pressure chamber, we examined different parameters such as the ET opening pressure (ETOP), ET opening duration (ETOD), and ET opening frequency (ETOF) in 11 experienced apnea divers and compared them to the parameters during the Valsalva and Toynbee maneuver. Results Standard values for ETOP, ETOD, and ETOF could be established for the Frenzel maneuver under standardized conditions in a hypo/hyperbaric pressure chamber. Compared to the Frenzel maneuver, ETOP was higher and ETOD longer (both p < 0.001) during the Valsalva maneuver whereas ETOP was lower and ETOD shorter (both p < 0.001) during the Toynbee maneuver. No difference regarding ETOF was observed between the Frenzel, Valsalva, and Toynbee maneuver. Discussion The Frenzel maneuver was shown to be at least as effective as the Valsalva maneuver concerning ET opening. We believe that knowledge of the Frenzel technique might facilitate the pressure equalization during diving and recommend implementation of an appropriate equalization training in apnea and scuba diving education.

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Section: Discussionmentioning

confidence: 99%

Section: Pressure Chamber Profilementioning

confidence: 99%

“…ETOD defines the time span between opening and closing of the ET. Evaluation of the ET parameters in detail are demonstrated in previously published articles [8,9,12,13].…”

Section: Eustachian Tube Function Parametermentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Prospective study on the Eustachian tube function during Frenzel maneuver in a hypobaric/hyperbaric pressure chamber

Wolber

Meyer

Knesic

et al. 2021

Eur Arch Otorhinolaryngol

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show abstract

“…Furthermore, researches on physiologic effects of hypobaric condition showed beneficial outcomes on cardiac mitochondria and advanced exercise performance [13, 14]. Hypobaric chamber model has been utilized to validate physical properties of medium and organism studied in it [15, 16]. They presented a diverse series of physiologic responses depending on the intensity and frequency of mechanical stimuli.…”

Section: Introductionmentioning

confidence: 99%

Brown Adipocyte and Splenocyte Co-Culture Maintains Regulatory T Cell Subset in Intermittent Hypobaric Conditions

Kang

Park

Shin

et al. 2019

Tissue Eng Regen Med

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Background:Brown adipocytes have thermogenic characteristics in neonates and elicit anti-inflammatory responses. We postulated that thermogenic brown adipocytes produce distinctive intercellular effects in a hypobaric state. The purpose of this study is to analyze the correlation between brown adipocyte and regulatory T cell (Treg) expression under intermittent hypobaric conditions.Methods:Brown and white adipocytes were harvested from the interscapular and flank areas of C57BL6 mice, respectively. Adipocytes were cultured with syngeneic splenocytes after isolation and differentiation. Intermittent hypobaric conditions were generated using cyclic negative pressure application for 48 h in both groups of adipocytes. Expression levels of Tregs (CD4 + CD25 + Foxp3 + T cells), cytokines [tumor necrosis factor-α (TNF-α) and interleukin-10 (IL-10), and the programmed death-ligand 1 (PD-L1)] co-inhibitory ligand were examined.Results:Splenocytes, cultured with brown and white adipocytes, exhibited comparable Treg expression in a normobaric state. Under hypobaric conditions, brown adipocytes maintained a subset of Tregs. However, a decrease in Tregs was found in the white adipocyte group. TNF-α levels increased in both groups under hypobaric conditions. In the brown adipocyte group, anti-inflammatory IL-10 expression increased significantly; meanwhile, IL-10 expression decreased in the white adipocyte group. PD-L1 levels increased more significantly in brown adipocytes than in white adipocytes under hypobaric conditions.Conclusion:Both brown and white adipocytes support Treg expression when they are cultured with splenocytes. Of note, brown adipocytes maintained Treg expression in intermittent hypobaric conditions. Anti-inflammatory cytokines and co-inhibitory ligands mediate the immunomodulatory effects of brown adipocytes under altered atmospheric conditions. Brown adipocytes showed the feasibility as a source of adjustment in physical stresses.

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Analyzing eustachian tube function in patients with symptoms of chronical Eustachian tube dysfunction by pressure chamber measurements

Meyer

Korthäuer

Jansen

et al. 2018

Eur Arch Otorhinolaryngol

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Reliability of Eustachian tube function measurements in a hypobaric and hyperbaric pressure chamber

Cited by 8 publications

References 18 publications

Prospective study on the Eustachian tube function during Frenzel maneuver in a hypobaric/hyperbaric pressure chamber

Prospective study on the Eustachian tube function during Frenzel maneuver in a hypobaric/hyperbaric pressure chamber

Brown Adipocyte and Splenocyte Co-Culture Maintains Regulatory T Cell Subset in Intermittent Hypobaric Conditions

Analyzing eustachian tube function in patients with symptoms of chronical Eustachian tube dysfunction by pressure chamber measurements

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