Document Detail


Bronchial nitric oxide flux and alveolar nitric oxide concentration after exposure to hyperoxia.
MedLine Citation:
PMID:  21961398     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
BACKGROUND: The fraction of nitric oxide in exhaled gas (FE(NO)) is reduced by 30-70% after exposure to partial pressures of oxygen (Po2) of 200-240 kPa for 90 min. The purpose of this study was to partition FE(NO) into its flow-independent alveolar and bronchial components. A reduced bronchial NO flux (JawNO) is associated with induced bronchoconstriction, while increased alveolar NO concentration (C(A)NO) is associated with increased alveolar dead space.
METHODS: There were 12 patients undergoing hyperbaric oxygen (HBO) therapy for 90 min at a Po2 of 240 kPa and 20 healthy subjects exposed to normobaric hyperoxia (NBO) breathing 100% oxygen for 90 min who were compared to a control group of 6 subjects breathing ambient air. FE(NO) was measured at flow rates from 30 to 250 ml x s(-1) before and after the exposures and the Högman Märilainen algorithm was used to calculate JawNO and C(A)NO.
RESULTS: FE(NO) at an expiratory flow rate of 50 ml x s(-1) was reduced from 17.6 +/- 8.3 to 12.3 +/- 6.3 ppb after HBO exposure and from 17.8 +/- 6.2 to 13.3 +/- 5.2 ppb after NBO exposure. There was a significant reduction in JawNO, but unchanged C(A)NO. There were no changes in the control experiment.
DISCUSSION: The reduction in FE(NO) after exposure to normobaric and hyperbaric hyperoxia appears to be predominantly an airway effect. An unchanged and low C(A)NO indicate preserved integrity of the gas exchange units without increased alveolar dead space at rest.
Authors:
Cecilie Caspersen; Trine Stensrud; Einar Thorsen
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Aviation, space, and environmental medicine     Volume:  82     ISSN:  0095-6562     ISO Abbreviation:  Aviat Space Environ Med     Publication Date:  2011 Oct 
Date Detail:
Created Date:  2011-10-03     Completed Date:  2011-11-03     Revised Date:  2012-05-21    
Medline Journal Info:
Nlm Unique ID:  7501714     Medline TA:  Aviat Space Environ Med     Country:  United States    
Other Details:
Languages:  eng     Pagination:  946-50     Citation Subset:  IM; S    
Affiliation:
Institute of Medicine, University of Bergen, Haukeland University Hospital, N-5021 Bergen, Norway.
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MeSH Terms
Descriptor/Qualifier:
Adult
Algorithms
Bronchi / metabolism*
Case-Control Studies
Female
Forced Expiratory Volume / physiology
Humans
Hyperbaric Oxygenation
Hyperoxia / metabolism*
Male
Middle Aged
Nitric Oxide / metabolism*
Oxygen / administration & dosage
Pulmonary Alveoli / metabolism*
Vital Capacity / physiology
Chemical
Reg. No./Substance:
10102-43-9/Nitric Oxide; 7782-44-7/Oxygen
Comments/Corrections
Comment In:
Aviat Space Environ Med. 2012 May;83(5):531; author reply 531-2   [PMID:  22606872 ]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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