Linked Life Data

3202503

Source:http://linkedlifedata.com/resource/pubmed/id/3202503

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1989-1-24
pubmed:abstractText
Recent studies examining the effects of hypoxia on diaphragm function have reached conflicting conclusions, with some reports suggesting an adverse effect of even mild hypoxemia while others indicate that the diaphragm may be extremely resistant to hypoxic stress. Diaphragm tension was not, however, directly measured nor was diaphragm length controlled in these previous reports, and it seems possible that methodologic limitations may have been responsible for these discrepant results. The purpose of the present study was to examine the effects of graded, steady-state hypoxia on diaphragm blood flow, oxygen extraction, oxygen consumption, and contractility using an in situ canine diaphragm strip preparation that permitted direct and continuous measurement of diaphragm length, tension, and blood flow. Measurements were made with the diaphragm at rest, during normoxia (PaO2, 90 to 160 mm Hg), mild hypoxia (PaO2, 45 to 60 mm Hg), and severe hypoxia (PaO2, 25 to 35 mm Hg); measurements were made with the diaphragm at rest, during rhythmic contractions at a tension time index (TTI) of 0.05, and with contractions at a TTI of 0.15. Decreases in arterial oxygenation resulted in progressive increases in blood flow and in the fractional extraction of oxygen in both resting and contracting diaphragm strips. At all levels of activity tested, blood flow and fractional extraction increased sufficiently to keep diaphragm oxygen consumption constant despite reductions in arterial oxygen content. Diaphragm contractility, as assessed from the tension generated in response to a range of electrical stimuli (1 to 80 Hz), was unaffected by hypoxia for trials performed with the diaphragm at rest and contracting at a TTI of 0.05.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0003-0805
pubmed:author
pubmed:issnType
Print
pubmed:volume
138
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1535-41
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Effect of hypoxia on diaphragm blood flow, oxygen uptake, and contractility.
pubmed:affiliation
Cleveland Metropolitan General Hospital, Department of Medicine, Case Western Reserve University, Ohio 44106.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't