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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
6
|
| pubmed:dateCreated |
1983-9-20
|
| pubmed:abstractText |
Inert tracer gas exchange across the human respiratory system is simulated in an asymmetric lung model for different oscillatory breathing patterns. The momentary volume-averaged alveolar partial pressure (PA), the expiratory partial pressure (PE), the mixed expiratory partial pressure (PE), the end-tidal partial pressure (PET), and the mean arterial partial pressure (Pa), are calculated as functions of the blood-gas partition coefficient (lambda) and the diffusion coefficient (D) of the tracer gas. The lambda values vary from 0.01 to 330.0 inclusive, and four values of D are used (0.5, 0.22, 0.1, and 0.01). Three ventilation-perfusion conditions corresponding to rest and mild and moderate exercise are simulated. Under simulated exercise conditions, we compute a reversed difference between PET and Pa compared with the rest condition. This reversal is directly reflected in the relation between the physiological dead space fraction (1--PE/Pa) and the Bohr dead space fraction (1--PE/PET). It is argued that the difference (PET--Pa) depends on the lambda of the tracer gas, the buffering capacity of lung tissue, and the stratification caused by diffusion-limited gas transport in the gas phase. Finally some determinants for the reversed difference (PET--Pa) and the significance for conventional gas analysis are discussed.
|
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:status |
MEDLINE
|
| pubmed:month |
Jun
|
| pubmed:issn |
0161-7567
|
| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:volume |
54
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
1745-53
|
| pubmed:dateRevised |
2004-11-17
|
| pubmed:meshHeading |
pubmed-meshheading:6874498-Humans,
pubmed-meshheading:6874498-Models, Biological,
pubmed-meshheading:6874498-Partial Pressure,
pubmed-meshheading:6874498-Pulmonary Artery,
pubmed-meshheading:6874498-Pulmonary Gas Exchange,
pubmed-meshheading:6874498-Respiration,
pubmed-meshheading:6874498-Respiratory Dead Space,
pubmed-meshheading:6874498-Ventilation-Perfusion Ratio
|
| pubmed:year |
1983
|
| pubmed:articleTitle |
Expiratory and arterial partial pressure relations under different ventilation-perfusion conditions.
|
| pubmed:publicationType |
Journal Article
|