Document Detail

Cerebral arterial and venous contributions to tissue oxygenation index measured using spatially resolved spectroscopy in newborn lambs.
MedLine Citation:
PMID:  21068664     Owner:  NLM     Status:  MEDLINE    
BACKGROUND: Bedside assessments of cerebral oxygenation are sought to monitor cerebral injury in patients undergoing intensive care. Spatially resolved spectroscopy measures tissue oxygenation index (TOI, %) which reflects mixed cerebral arterial and venous oxygenations. We aimed to evaluate arterial and venous components of TOI (cerebral arterial to venous volume ratio [A:V ratio]) in the newborn lamb brain using cerebral arterial and venous blood samples, and to investigate the impact of acute hypoxemia on the A:V ratio and TOI.
METHOD: Nine lambs were ventilated with varied inspired oxygen to generate arterial oxygen saturations between 25% and 100%. Cerebral arterial and venous oxygen saturations analyzed using cooximeter of arterial and superior sagittal sinus blood were used to estimate TOI (TOIcox), assuming cerebral A:V ratio of 25:75. TOIcox was compared with the TOI measured by spatially resolved spectroscopy (TOIsrs). Actual cerebral arterial and venous volume fractions were reestimated using TOIsrs = cerebral arterial volume fraction cerebral arterial oxygen saturation + cerebral venous volume fraction*cerebral venous oxygen saturation.
RESULTS: Median (range) TOIsrs was 48.5% (32.0-64.1%), and TOIcox was 48.4% (13.7-74.4%), and the two were significantly correlated (R = 0.77). The mean difference between TOIsrs and TOIcox was 2.4% (limits of agreement ± 18.1%). The TOIsrs - TOIcox difference varied with oxygen saturations, with TOIsrs higher than TOIcox at low saturations, and lower at high saturations. Cerebral arterial volume fraction was 22.9-27.5% in normoxia and markedly increased in hypoxemia.
CONCLUSION: TOI corresponds with cerebral oxygenation. The variable agreement of TOIsrs with TOIcox may reflect changes in cerebral A:V ratio due to arterial oxygenation-related vasoreactivity.
Flora Y Wong; Theodora Alexiou; Thilini Samarasinghe; Vojta Brodecky; Adrian M Walker
Related Documents :
567334 - Modifications by stretches of the mechanical response of isolated cerebral and extracer...
9409424 - Combined direct and indirect reconstructive vascular surgery on the fronto-parieto-occi...
20124934 - The anatomy of the callosomarginal artery: applications to microsurgery and endovascula...
4016594 - The association of extracranial and intracranial vascular malformations in children.
18677524 - Aneurysm clipping after endovascular treatment with coils: a report of 13 cases.
22879554 - Successful repair of bicuspid aortic valve with two raphae.
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Anesthesiology     Volume:  113     ISSN:  1528-1175     ISO Abbreviation:  Anesthesiology     Publication Date:  2010 Dec 
Date Detail:
Created Date:  2010-11-24     Completed Date:  2010-12-22     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  1300217     Medline TA:  Anesthesiology     Country:  United States    
Other Details:
Languages:  eng     Pagination:  1385-91     Citation Subset:  AIM; IM    
The Ritchie Centre, Monash Institute of Medical Research, Monash University, Melbourne, Victoria, Australia.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Animals, Newborn / physiology*
Anoxia / blood
Blood Volume / physiology
Cerebral Arteries / physiology*
Cerebral Veins / physiology*
Cerebrovascular Circulation / physiology
Oxygen / blood
Oxygen Consumption / physiology*
Spectroscopy, Near-Infrared / methods
Reg. No./Substance:

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

Previous Document:  Effects of early neuronal and delayed inducible nitric oxide synthase blockade on cardiovascular, re...
Next Document:  Sevoflurane-induced preconditioning: impact of protocol and aprotinin administration on infarct size...