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Author Klein, Klaus Ulrich ♦ Glaser, Martin ♦ Reisch, Robert ♦ Tresch, Achim ♦ Werner, Christian ♦ Engelhard, Kristin
Source World Health Organization (WHO)-Global Index Medicus
Content type Text
Publisher Lippincott Williams & Wilkins
File Format HTM / HTML
Language English
Difficulty Level Medium
Subject Domain (in DDC) Natural sciences & mathematics ♦ Chemistry & allied sciences ♦ Life sciences; biology ♦ Physiology & related subjects ♦ Biochemistry ♦ Natural history of organisms ♦ Technology ♦ Medicine & health ♦ Human anatomy, cytology, histology ♦ Human physiology ♦ Pharmacology and therapeutics ♦ Diseases ♦ Surgery & related medical specialties ♦ Manufacture for specific uses ♦ Precision instruments & other devices
Subject Domain (in MeSH) Cardiovascular System ♦ Anatomy ♦ Eukaryota ♦ Organisms ♦ Inorganic Chemicals ♦ Organic Chemicals ♦ Chemicals and Drugs ♦ Diagnosis ♦ Surgical Procedures, Operative ♦ Analytical, Diagnostic and Therapeutic Techniques and Equipment ♦ Physical Phenomena ♦ Circulatory and Respiratory Physiological Phenomena ♦ Biological Sciences ♦ Persons ♦ Persons
Subject Keyword Discipline Anesthesiology ♦ Carbon Dioxide ♦ Blood ♦ Cerebral Veins ♦ Physiology ♦ Cerebrovascular Circulation ♦ Craniotomy ♦ Methyl Ethers ♦ Pharmacology ♦ Oxygen ♦ Adult ♦ Aged ♦ Capillaries ♦ Drug Effects ♦ Cerebral Arteries ♦ Methods ♦ Female ♦ Humans ♦ Laser-doppler Flowmetry ♦ Male ♦ Middle Aged ♦ Monitoring, Intraoperative ♦ Partial Pressure ♦ Comparative Study ♦ Journal Article
Abstract BACKGROUND: Intraoperative routine monitoring of cerebral blood flow and oxygenation remains a technological challenge. Using the physiological principle of carbon dioxide reactivity of cerebral vasculature, we investigated a recently developed neuromonitoring device (oxygen-to-see, O2C device) for simultaneous measurements of regional cerebral blood flow (rvCBF), blood flow velocity (rvVelo), oxygen saturation (srvO2), and hemoglobin amount (rvHb) at the capillary venous level in patients subjected to craniotomy. METHODS: Twenty-six neurosurgical patients were randomly assigned to anesthesia with 1.4% or 2.0% sevoflurane end-tidal concentration. After craniotomy, a fiberoptic probe was applied on a macroscopically healthy surface of cerebral tissue next to the site of surgery. Simultaneous measurements in 2 and 8 mm cerebral depth were performed in each patient during lower (35 mm Hg) and higher (45 mm Hg) levels (random order) of arterial carbon dioxide partial pressure (PaCO2). The principle of these measurements relies on the combination of laser-Doppler flowmetry (rvCBF, rvVelo) and photo-spectrometry (srvO2, rvHb). Linear models were fitted to test changes of end points (rvCBF, rvVelo, srvO2, rvHb) in response to lower and higher levels of PaCO2, 1.4% and 2.0% sevoflurane end-tidal concentration, and 2 and 8 mm cerebral depth. RESULTS: RvCBF and rvVelo were elevated by PaCO2 independent of sevoflurane concentration in 2 and 8 mm depth of cerebral tissue (P < 0.001). Higher PaCO2 induced an increase in mean srvO2 from 50% to 68% (P < 0.001). RvVelo (P < 0.001) and srvO2 (P = 0.007) were higher in 8 compared with 2 mm cerebral depth. RvHb was not influenced by alterations in PaCO2 but positively correlated to sevoflurane concentration (P = 0.005). CONCLUSIONS: Increases in rvCBF and rvVelo by PaCO2 suggest preserved hypercapnic vasodilation under anesthesia with sevoflurane 1.4% and 2.0% end-tidal concentration. A consecutive increase in srvO2 implies that cerebral arteriovenous difference in oxygen was decreased by elevated PaCO2. Unchanged levels of rvHb signify that there was no blood loss during measurements. Data suggest that the device allows detection of local changes in blood flow and oxygen saturation in response to different PaCO2 levels in predominant venous cerebral microvessels.
Description Country affiliation: Germany
Author Affiliation: Klein KU ( Department of Anesthesiology, Johannes Gutenberg-University, Langenbeckstrasse 1, 55131 Mainz, Germany. kuklein@uni-mainz.de)
ISSN 00032999
Educational Role Student ♦ Teacher
Age Range above 22 year
Educational Use Reading ♦ Research ♦ Self Learning
Interactivity Type Expositive
Education Level UG and PG
Learning Resource Type Article
Publisher Date 2009-07-01
Publisher Place United States
e-ISSN 15267598
Journal Anesthesia & Analgesia
Volume Number 109
Issue Number 1


Source: WHO-Global Index Medicus