| Calculating alveolar capillary conductance and pulmonary capillary blood volume: comparing the multiple- and single-inspired oxygen tension methods. | |
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MedLine Citation:
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PMID: 20538842 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Key elements for determining alveolar-capillary membrane conductance (Dm) and pulmonary capillary blood volume (Vc) from the lung diffusing capacity (Dl) for carbon monoxide (DlCO) or for nitric oxide (DlNO) are the reaction rate of carbon monoxide with hemoglobin (thetaCO) and the DmCO/DlNO relationship (alpha-ratio). Although a range of values have been reported, currently there is no consensus regarding these parameters. The study purpose was to define optimal parameters (thetaCO, alpha-ratio) that would experimentally substantiate calculations of Dm and Vc from the single-inspired O2 tension [inspired fraction of O2 (FiO2)] method relative to the multiple-FiO2 method. Eight healthy men were studied at rest and during moderate exercise (80-W cycle). Dm and Vc were determined by the multiple-FiO2 and single-FiO2 methods (rebreathe technique) and were tabulated by applying previously reported thetaCO equations (both methods) and by varying the alpha-ratio (single-FiO2 method) from 1.90 to 2.50. Values were then compared between methods throughout the examined alpha-ratios. Dm and Vc were critically dependent on the applied thetaCO equation. For the multiple-FiO2 method, Dm was highly variable between thetaCO equations (rest and exercise); the range of Vc was less widespread. For the single-FiO2 method, the thetaCO equation by Reeves and Park (1992) combined with an alpha-ratio between 2.08 and 2.26 gave values for Dm and Vc that most closely matched those from the multiple-FiO2 method and were also physiologically plausible compared with predicted values. We conclude that the parameters used to calculate Dm and Vc values from the single-FiO2 method (using DlCO and DlNO) can significantly influence results and should be evaluated within individual laboratories to obtain optimal values. |
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Authors:
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Maile L Ceridon; Kenneth C Beck; Thomas P Olson; Jordan A Bilezikian; Bruce D Johnson |
Publication Detail:
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Type: Comparative Study; Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't Date: 2010-06-10 |
Journal Detail:
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Title: Journal of applied physiology (Bethesda, Md. : 1985) Volume: 109 ISSN: 1522-1601 ISO Abbreviation: J. Appl. Physiol. Publication Date: 2010 Sep |
Date Detail:
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Created Date: 2010-09-10 Completed Date: 2011-01-12 Revised Date: 2011-09-13 |
Medline Journal Info:
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Nlm Unique ID: 8502536 Medline TA: J Appl Physiol Country: United States |
Other Details:
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Languages: eng Pagination: 643-53 Citation Subset: IM |
Affiliation:
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Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Gonda 5-369, Rochester, MN 55905, USA. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Administration, Inhalation Adolescent Adult Blood Volume* Capillaries / physiology Capillary Permeability Carbon Monoxide / administration & dosage, blood Exercise Hemoglobins / metabolism Humans Inhalation* Male Microcirculation* Models, Biological Nitric Oxide / administration & dosage, blood Oxygen / administration & dosage*, blood Pulmonary Alveoli / blood supply* Pulmonary Circulation* Pulmonary Diffusing Capacity* Reproducibility of Results Rest Time Factors Young Adult |
| Grant Support | |
ID/Acronym/Agency:
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HL-71478/HL/NHLBI NIH HHS |
| Chemical | |
Reg. No./Substance:
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0/Hemoglobins; 10102-43-9/Nitric Oxide; 630-08-0/Carbon Monoxide; 7782-44-7/Oxygen |
| Comments/Corrections | |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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