Document Detail

Precision of coherence analysis to detect cerebral autoregulation by near-infrared spectroscopy in preterm infants.
MedLine Citation:
PMID:  20615031     Owner:  NLM     Status:  MEDLINE    
Coherence between spontaneous fluctuations in arterial blood pressure (ABP) and the cerebral near-infrared spectroscopy signal can detect cerebral autoregulation. Because reliable measurement depends on signals with high signal-to-noise ratio, we hypothesized that coherence is more precisely determined when fluctuations in ABP are large rather than small. Therefore, we investigated whether adjusting for variability in ABP (variability(ABP)) improves precision. We examined the impact of variability(ABP) within the power spectrum in each measurement and between repeated measurements in preterm infants. We also examined total monitoring time required to discriminate among infants with a simulation study. We studied 22 preterm infants (GA<30) yielding 215 10-min measurements. Surprisingly, adjusting for variability(ABP) within the power spectrum did not improve the precision. However, adjusting for the variability(ABP) among repeated measurements (i.e., weighting measurements with high variability(ABP) in favor of those with low) improved the precision. The evidence of drift in individual infants was weak. Minimum monitoring time needed to discriminate among infants was 1.3-3.7 h. Coherence analysis in low frequencies (0.04-0.1 Hz) had higher precision and statistically more power than in very low frequencies (0.003-0.04 Hz). In conclusion, a reliable detection of cerebral autoregulation takes hours and the precision is improved by adjusting for variability(ABP) between repeated measurements.
Gitte Holst Hahn; Karl Bang Christensen; Terence S Leung; Gorm Greisen
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Journal of biomedical optics     Volume:  15     ISSN:  1560-2281     ISO Abbreviation:  J Biomed Opt     Publication Date:    2010 May-Jun
Date Detail:
Created Date:  2010-07-09     Completed Date:  2010-10-29     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  9605853     Medline TA:  J Biomed Opt     Country:  United States    
Other Details:
Languages:  eng     Pagination:  037002     Citation Subset:  IM    
Copenhagen University Hospital - Rigshospitalet, Department of Neonatology, Blegdamsvej 9, Copenhagen, 2100 Denmark.
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MeSH Terms
Analysis of Variance
Blood Pressure / physiology
Cerebral Cortex / physiology*
Fourier Analysis*
Hemoglobins / chemistry
Infant, Newborn
Infant, Premature / physiology*
Oxyhemoglobins / chemistry
Sensitivity and Specificity
Spectroscopy, Near-Infrared / methods*
Time Factors
Reg. No./Substance:
0/Hemoglobins; 0/Oxyhemoglobins; 9008-02-0/deoxyhemoglobin

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

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