Document Detail

Calculating alveolar capillary conductance and pulmonary capillary blood volume: comparing the multiple- and single-inspired oxygen tension methods.
MedLine Citation:
PMID:  20538842     Owner:  NLM     Status:  MEDLINE    
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.
Maile L Ceridon; Kenneth C Beck; Thomas P Olson; Jordan A Bilezikian; Bruce D Johnson
Publication Detail:
Type:  Comparative Study; Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't     Date:  2010-06-10
Journal Detail:
Title:  Journal of applied physiology (Bethesda, Md. : 1985)     Volume:  109     ISSN:  1522-1601     ISO Abbreviation:  J. Appl. Physiol.     Publication Date:  2010 Sep 
Date Detail:
Created Date:  2010-09-10     Completed Date:  2011-01-12     Revised Date:  2013-09-26    
Medline Journal Info:
Nlm Unique ID:  8502536     Medline TA:  J Appl Physiol (1985)     Country:  United States    
Other Details:
Languages:  eng     Pagination:  643-53     Citation Subset:  IM    
Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, Gonda 5-369, Rochester, MN 55905, USA.
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MeSH Terms
Administration, Inhalation
Blood Volume*
Capillaries / physiology
Capillary Permeability
Carbon Monoxide / administration & dosage,  blood
Hemoglobins / metabolism
Models, Biological
Nitric Oxide / administration & dosage,  blood
Oxygen / administration & dosage*,  blood
Pulmonary Alveoli / blood supply*
Pulmonary Circulation*
Pulmonary Diffusing Capacity*
Reproducibility of Results
Time Factors
Young Adult
Grant Support
Reg. No./Substance:
0/Hemoglobins; 10102-43-9/Nitric Oxide; 630-08-0/Carbon Monoxide; 7782-44-7/Oxygen

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

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