Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1992-5-13
pubmed:abstractText
To explain the contradictory results in the literature regarding the effects of inspiratory diaphragmatic descent on inferior vena caval (IVC) venous return, we evaluated changes in total IVC flow as well as regional splanchnic and nonsplanchnic IVC flows by use of ultrasound flow probes placed around the thoracic and subhepatic abdominal IVC during phrenic nerve stimulation (PNS) in anesthetized open-chest dogs. With the abdomen closed (n = 6), PNS under hypervolemic conditions increased the total IVC flow by enhancing the splanchnic IVC flow, with a transient decrease in the nonsplanchnic IVC flow (P less than 0.05). Under hypovolemic conditions, PNS initially increased the total IVC flow but later decreased the total IVC flow by reducing the nonsplanchnic IVC flow, associated with a venous pressure gradient in the IVC across the diaphragm (P less than 0.05), consistent with development of a vascular waterfall. With the abdomen widely open, the mobile abdominal contents eviscerated, and the subhepatic IVC occluded (n = 5), PNS increased the splanchnic IVC flow associated only with an increase in focal contact pressure over the liver without any increase in general abdominal pressure (Pab) (P less than 0.05). These results suggest that our previously proposed concept of abdominal vascular zone conditions (J. Appl. Physiol. 69: 1961-1972, 1990) is useful as a global approximation to understand the effects of respiratory-induced changes in Pab's on the total and regional IVC venous return. Nonhomogeneous distribution of Pab's during diaphragmatic descent may need to be considered to explain all aspects of the behavior of the intact IVC system.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
8750-7587
pubmed:author
pubmed:issnType
Print
pubmed:volume
72
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
597-607
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Effects of inspiratory diaphragmatic descent on inferior vena caval venous return.
pubmed:affiliation
Department of Anesthesiology and Critical Care Medicine, Johns Hopkins Medical Institutions, Baltimore, Maryland 21205.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.