Linked Life Data

9773851

Source:http://linkedlifedata.com/resource/pubmed/id/9773851

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1998-12-29
pubmed:abstractText
We have previously reported concordant changes in cerebral intravascular oxygenation measured by near infrared spectroscopy (NIRS) and mean arterial blood pressure (MAP) in premature infants. We hypothesized that the cerebral oxygenation changes are caused by MAP-induced alterations in cerebral blood flow (CBF) and studied these parameters in neonatal piglets (n = 6). Changes in cerebral intravascular oxygenation were measured by NIRS from the hemoglobin difference (HbD) signal (oxyhemoglobin-deoxyhemoglobin). CBF was measured by the radioactive microsphere technique. The cerebral circulation was also monitored by Doppler determinations of CBF velocity (time average mean velocity) in the anterior cerebral artery. Hypotension to <50% of baseline MAP was achieved by a ligature around the ascending aorta. Arterial oxygenation was maintained constant by mechanical ventilation. As observed in our studies of premature infants, cerebral HbD and MAP showed concordant changes. Hypotension was accompanied by significant decreases both in CBF (42.8 +/- 12.5% of baseline p < 0.01) and HbD (-65.0 +/- 22.0 micromol/L x dpf, p < 0.01). HbD was significantly correlated with MAP (p < 0.05) and time average mean velocity (p = 0.01). Importantly, decreases in cerebral total hemoglobin (HbT), a measure of cerebral blood volume, did not correlate significantly with decreases in MAP. We conclude that 1) decreases in cerebral intravascular oxygenation, as assessed by NIRS, observed with decreases in MAP reflect a decline in CBF, and hence oxygen delivery, 2) the HbD signal is more sensitive to changes in CBF than the HbT signal, and 3) NIRS recordings may have clinical utility in detecting cerebral ischemia.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0031-3998
pubmed:author
pubmed:issnType
Print
pubmed:volume
44
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
591-5
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Near infrared spectroscopy detects cerebral ischemia during hypotension in piglets.
pubmed:affiliation
Joint Program in Neonatology, Harvard Medical School, Boston, Massachusetts 02115, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.