Linked Life Data

15155713

Source:http://linkedlifedata.com/resource/pubmed/id/15155713

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
2004-9-10
pubmed:abstractText
We studied the respiratory output in five subjects exposed to parabolic flights [gravity vector 1, 1.8 and 0 gravity vector in the craniocaudal direction (Gz)] and when switching from sitting to supine (legs bent at the knees). Despite differences in total respiratory compliance (highest at 0 Gz and in supine and minimum at 1.8 Gz), no significant changes in elastic inspiratory work were observed in the various conditions, except when comparing 1.8 Gz with 1 Gz (subjects were in the seated position in all circumstances), although the elastic work had an inverse relationship with total respiratory compliance that was highest at 0 Gz and in supine posture and minimum at 1.8 Gz. Relative to 1 Gz, lung resistance (airways plus lung tissue) increased significantly by 52% in the supine but slightly decreased at 0 Gz. We calculated, for each condition, the tidal volume changes based on the energy available in the preceding phase and concluded that an increase in inspiratory muscle output occurs when respiratory load increases (e.g., going from 0 to 1.8 Gz), whereas a decrease occurs in the opposite case (e.g., from 1.8 to 0 Gz). Despite these immediate changes, ventilation increased, going to 1.8 and 0 Gz (up to approximately 23%), reflecting an increase in mean inspiratory flow rate, tidal volume, and respiratory frequency, while ventilation decreased (approximately -14%), shifting to supine posture (transition time approximately 15 s). These data suggest a remarkable feature in the mechanical arrangement of the respiratory system such that it can maintain the ventilatory output with small changes in inspiratory muscle work in face of considerable changes in configuration and mechanical properties.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
8750-7587
pubmed:author
pubmed:issnType
Print
pubmed:volume
97
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1219-26
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Effect of changing the gravity vector on respiratory output and control.
pubmed:affiliation
TBM Lab, Dipartimento di Bioingegneria, Politecnico di Milano, I-20133 Milan, Italy.
pubmed:publicationType
Journal Article, Clinical Trial, Research Support, Non-U.S. Gov't