Linked Life Data

1892289

Source:http://linkedlifedata.com/resource/pubmed/id/1892289

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3 Pt 1
pubmed:dateCreated
1991-10-17
pubmed:abstractText
A common method for analyzing a multibreath nitrogen washout (MBNW) is to perform moment analysis and derive the mean dilution number (MDN). A homogeneously mixed alveolar space with zero series dead space (VD = 0) will always result in a MDN = 1, regardless of breathing pattern. A higher MDN implies more inhomogeneity. But, if VD greater than 0, the MDN can become sensitive (artificially high) to VD/VT ratios. We present an alveolar-based mean dilution number (AMDN) that uses the cumulative expired alveolar volume. Unlike the MDN, the AMDN for a homogeneously mixed alveolar space is unity, regardless of VD or VT, and hence should be a more appropriate index of inhomogeneity at the alveolar level. Two sets of experiments were used to compare the AMDN with the MDN. First, a MBNW was performed by five healthy subjects at spontaneous VD/VT and at a low VD/VT achieved by a controlled increase in VT. Here, the MDN decreased from 1.98 +/- 0.1 to 1.79 +/- 0.06, whereas the AMDN was essentially unchanged (1.42 +/- 0.04 to 1.38 +/- 0.06). Second, MBNW values from seven healthy subjects, five with cystic fibrosis, and 10 asthmatic subjects (before and after bronchodilation) were analyzed. Compared with the MDN, the AMDN showed a significantly wider separation between clinical groups. Also, the AMDN demonstrated an increased variability within both sick groups versus a decrease in the healthy group. We conclude that the AMDN is superior to the MDN because of its decreased sensitivity to breathing pattern but increased sensitivity to degree of disease.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0003-0805
pubmed:author
pubmed:issnType
Print
pubmed:volume
144
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
513-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Moment analysis of a multibreath nitrogen washout based on an alveolar gas dilution number.
pubmed:affiliation
Department of Biomedical Engineering, Boston University, Massachusetts 02215.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.