| Level alterations of the 2f (1)-f (2) distortion product due to hypoxia in the guinea pig depend on the stimulus frequency. | |
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MedLine Citation:
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PMID: 19629511 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Increased intracranial pressure (ICP) is known to affect the levels of distortion product otoacoustic emissions (DPOAEs) in a frequency-specific manner. DPOAEs might, therefore, be used for monitoring the ICP non-invasively. Hypoxia can also cause alterations of DPOAE levels, which can be distinguished from ICP-related changes only, when their characteristics, in particular frequency specificity, are known in detail. DPOAEs at f (2) = 2, 4, 8, 12 and 16 kHz and oxygen saturation (SaO(2)) were continuously monitored in nine spontaneously breathing guinea pigs, anaesthetized by i.m. administration of midazolam, medetomidin and fentanyl, during the respiration of a gas mixture of N(2)O and O(2) containing either 30% O(2) or 13% O(2). Fourteen hypoxic intervals in eight animals were included into final data analysis. Characteristic hypoxic level alterations with a level decrease and a remarkable level destabilization during hypoxia, and a pronounced reversible level decrease after reoxygenation were observed at the frequencies of 4, 8 and 16 kHz. At 2 and 12 kHz, the only reproducible effect of hypoxia was an increased fluctuation of the DPOAE level, which was significantly less pronounced compared with the other frequencies (P < 0.05 for 12 vs. 16 and 8 kHz and for 2 vs. 16 kHz). DPOAE level alterations due to hypoxia depend on the frequency in guinea pigs. Studies in human are warranted to improve non-invasive ICP monitoring with DPOAE by the detection of hypoxia-related changes. |
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Authors:
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Bernhard Olzowy; Gregor von Gleichenstein; Martin Canis; Nikolaus Plesnila; Sebastian Strieth; Christoph Deppe; Klaus Mees |
Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't Date: 2009-07-21 |
Journal Detail:
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Title: European archives of oto-rhino-laryngology : official journal of the European Federation of Oto-Rhino-Laryngological Societies (EUFOS) : affiliated with the German Society for Oto-Rhino-Laryngology - Head and Neck Surgery Volume: 267 ISSN: 1434-4726 ISO Abbreviation: Eur Arch Otorhinolaryngol Publication Date: 2010 Mar |
Date Detail:
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Created Date: 2010-01-26 Completed Date: 2010-04-22 Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 9002937 Medline TA: Eur Arch Otorhinolaryngol Country: Germany |
Other Details:
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Languages: eng Pagination: 351-5 Citation Subset: IM |
Affiliation:
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Department of Otorhinolaryngology, Head and Neck Surgery, Ludwig Maximilians University of Munich Medical Center, Marchioninistr. 15, 81377 M?nchen, Germany. bernhard.olzowy@med.uni-muenchen.de |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Animals Anoxia / physiopathology* Guinea Pigs Intracranial Pressure / physiology* Monitoring, Physiologic Otoacoustic Emissions, Spontaneous / physiology* Reference Values Signal Processing, Computer-Assisted* Sound Spectrography |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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