| Continuous time-domain analysis of cerebrovascular autoregulation using near-infrared spectroscopy. | |
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MedLine Citation:
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PMID: 17761921 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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BACKGROUND AND PURPOSE: Assessment of autoregulation in the time domain is a promising monitoring method for actively optimizating cerebral perfusion pressure (CPP) in critically ill patients. The ability to detect loss of autoregulatory vasoreactivity to spontaneous fluctuations in CPP was tested with a new time-domain method that used near-infrared spectroscopic measurements of tissue oxyhemoglobin saturation in an infant animal model. METHODS: Piglets were made progressively hypotensive over 4 to 5 hours by inflation of a balloon catheter in the inferior vena cava, and the breakpoint of autoregulation was determined using laser-Doppler flowmetry. The cerebral oximetry index (COx) was determined as a moving linear correlation coefficient between CPP and INVOS cerebral oximeter waveforms during 300-second periods. A laser-Doppler derived time-domain analysis of spontaneous autoregulation with the same parameters (LDx) was also determined. RESULTS: An increase in the correlation coefficient between cerebral oximetry values and dynamic CPP fluctuations, indicative of a pressure-passive relationship, occurred when CPP was below the steady state autoregulatory breakpoint. This COx had 92% sensitivity (73% to 99%) and 63% specificity (48% to 76%) for detecting loss of autoregulation attributable to hypotension when COx was above a threshold of 0.36. The area under the receiver-operator characteristics curve for the COx was 0.89. COx correlated with LDx when values were sorted and averaged according to the CPP at which they were obtained (r=0.67). CONCLUSIONS: The COx is sensitive for loss of autoregulation attributable to hypotension and is a promising monitoring tool for determining optimal CPP for patients with acute brain injury. |
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Authors:
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Ken M Brady; Jennifer K Lee; Kathleen K Kibler; Piotr Smielewski; Marek Czosnyka; R Blaine Easley; Raymond C Koehler; Donald H Shaffner |
Publication Detail:
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Type: Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't Date: 2007-08-30 |
Journal Detail:
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Title: Stroke; a journal of cerebral circulation Volume: 38 ISSN: 1524-4628 ISO Abbreviation: Stroke Publication Date: 2007 Oct |
Date Detail:
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Created Date: 2007-09-25 Completed Date: 2007-10-18 Revised Date: 2011-09-26 |
Medline Journal Info:
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Nlm Unique ID: 0235266 Medline TA: Stroke Country: United States |
Other Details:
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Languages: eng Pagination: 2818-25 Citation Subset: IM |
Affiliation:
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Johns Hopkins University School of Medicine, Department of Anesthesiology, Division of Pediatric Anesthesiology and Critical Care Medicine, 600 North Wolfe Street, Blalock 904, Baltimore, MD 21287, USA. kbrady5@jhmi.edu |
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| MeSH Terms | |
Descriptor/Qualifier:
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Acute Disease Age Factors Animals Brain Injuries / diagnosis, physiopathology* Cerebrovascular Circulation / physiology* Disease Models, Animal Homeostasis / physiology Hypotension / diagnosis, physiopathology* Laser-Doppler Flowmetry Monitoring, Physiologic / instrumentation*, methods Oximetry Sensitivity and Specificity Spectroscopy, Near-Infrared / methods* Swine |
| Grant Support | |
ID/Acronym/Agency:
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NS20020/NS/NINDS NIH HHS; P01 NS020020-240002/NS/NINDS NIH HHS |
| Comments/Corrections | |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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