Linked Life Data

2191817

Source:http://linkedlifedata.com/resource/pubmed/id/2191817

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1990-7-26
pubmed:abstractText
In seated adult cystic fibrosis (CF) patients, vascular recruitment of the relatively normal regions of the pulmonary circulation could occur in response to vascular destruction or hypoxia elsewhere in the pulmonary vasculature, thus limiting overall reductions in the single breath CO diffusing capacity (DLcoSB) with advancing disease. The purpose of this study was to determine the extent to which pulmonary capillary recruitment limits reductions in DLcoSB in seated adult cystic fibrosis patients, to define the role of hypoxia, and to develop strategies to improve detection of diffusion abnormalities in this disease. In normal subjects and adult CF patients breathing room air, and in a subgroup, after breathing both 40% and 100% O2 for 20 min, we measured changes (compared to sitting) in the three equation DLcoSB by changing transvascular pressure either with 15 degrees head down position (15 degrees HD), or with high negative inspiratory pressure (HNIP). In CF patients breathing room air, the changes in DLcoSB with both 15 degrees HD and HNIP were significantly smaller (p less than 0.01) than in controls and the positional changes correlated with the degree of airway obstruction. Although CF patients had no significant positional changes in diffusional resistance (1/DLcoSB) breathing room air, the positional changes in 1/DLcoSB after breathing 100% O2 for 20 min were similar in magnitude to the positional changes in normal subjects. We conclude that compensatory pulmonary capillary recruitment occurs in the relatively normal regions of the pulmonary vasculature breathing room air in the resting seated position in CF patients, thus minimizing reductions in DLcoSB in the seated position. This accounts for reduced responses of DLcoSB to both position and HNIP. The improved positional changes in 1/DLcoSB breathing hyperoxic gas mixtures in CF patients suggests that the vascular recruitment breathing room air is partly due to hypoxic vasoconstriction rather than due solely to fixed pathological changes in the pulmonary vasculature.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0147-958X
pubmed:author
pubmed:issnType
Print
pubmed:volume
13
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
82-91
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Pulmonary diffusing capacity in adult cystic fibrosis: reduced positional changes are partially reversed by hyperoxia.
pubmed:affiliation
Department of Medicine, University Hospital, University of Saskatchewan, Saskatoon.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't