Linked Life Data

8256916

Source:http://linkedlifedata.com/resource/pubmed/id/8256916

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6 Pt 1
pubmed:dateCreated
1994-1-11
pubmed:abstractText
Positive end-expiratory pressure (PEEP) commonly decreases cardiac output. The major cause of this is believed to be decreased venous return due to increased right atrial pressure. We hypothesized that when the lungs were hyperinflated they could also restrict venous return by directly compressing the thoracic vena cavae. We measured the longitudinal distribution of pressure in the thoracic vena cavae of 10 dogs on and off 10 mm Hg PEEP, in the supine (S), prone (P), right lateral (RL), and left lateral decubitus (LL) positions. In the superior vena cava (SVC) both on and off PEEP, and in the inferior vena cava (IVC) off PEEP, pressure fell uniformly from the thoracic inlet to the right atrium. However, in the IVC on PEEP, intravascular pressure fell abruptly by up to 5 mm Hg. This pressure drop occurred in a discrete (1 to 2-cm) segment of the IVC, suggesting a localized increased in extravascular surface pressure. When this pressure inflection was present, changes in right atrial pressure had no effect on pressure in the IVC upstream of the inflection, consistent with a "vascular waterfall." These observations were most prominent in the LL, least common in the RL, and variably present in the P and S positions. Occlusion of the right bronchus intermedius prior to PEEP (preventing right lower, middle, and accessory lobe inflation) prevented the appearance of the pressure inflection during PEEP in the LL but not in the S or P positions. We conclude that PEEP impedes venous return partly by direct compression of the IVC, predominantly in positions in which the IVC is non-dependent.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0003-0805
pubmed:author
pubmed:issnType
Print
pubmed:volume
148
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1657-64
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Effects of positive end-expiratory pressure and body position on pressure in the thoracic great veins.
pubmed:affiliation
Department of Medicine, Johns Hopkins Asthma and Allergy Center, Baltimore, MD 21224.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.