Search results for "Cerebral blood flow."
showing 8 items of 138 documents
“Small Volume Resuscitation” as Treatment of Cerebral Blood Flow Disturbances and Increased ICP in Trauma and Ischemia
1996
“Small volume resuscitation” (SVR) is a promising concept for the treatment of shock and trauma patients. SVR utilizes the fast infusion of a small volume of hypertonic saline to mobilize intraendothelial and parenchymal water to expand and restitute intravascular volume. Therefore it seems warranted to also consider SVR for the treatment of disturbances of the cerebral circulation and of increased intracranial pressure (ICP). The current study uses a rabbit model of global cerebral ischemia combined with mild hemorrhage to test SVR. Somatosensory evoked potentials (SEPs) serve as a short-term outcome parameter. The data demonstrate a beneficial effect on ICP, a better reperfusion, and an i…
Temporal and Spatial Evolution of Cortical Blood Flow in the Penumbra of Venous Infarcts
2001
A cortical venous infarction model has been evaluated regarding the temporal and spatial evolution of regional flow reduction. Two cortical veins were occluded photochemically with rose bengal and fiberoptic illumination. Seven rats served to demonstrate effects on regional cortical blood flow using laser Doppler scanning. After two-vein occlusion, there was a widespread reduction of flow that gradually deteriorated after vein occlusion when regional cortical flow in a 3.5 x 7.0 mm window: after 15 min it had decreased to 57.8% ± 8.0%, and after 75 min it was 34.3% ± 5.4%. Infarct volumes as determined in 10 rats 5 days after two-vein occlusion had an average size of 3.6 ± 0.7 mm3. The data…
Cerebral Autoregulation in Non-Brain Injured Patients: A Systematic Review.
2021
Introduction: Cerebral autoregulation (CA) plays a fundamental role in the maintenance of adequate cerebral blood flow (CBF). CA monitoring, through direct and indirect techniques, may guide an appropriate therapeutic approach aimed at improving CBF and reducing neurological complications; so far, the role of CA has been investigated mainly in brain-injured patients. The aim of this study is to investigate the role of CA in non-brain injured patients.Methods: A systematic consultation of literature was carried out. Search terms included: “CA and sepsis,” “CA and surgery,” and “CA and non-brain injury.”Results: Our research individualized 294 studies and after screening, 22 studies were anal…
Lateralization Effects on Cerebral Blood Flow in Patients With Unilateral Pulsatile Tinnitus Measured With Arterial Spin Labeling
2020
Purpose: To investigate cerebral blood flow (CBF) differences in patients with left- and right-sided pulsatile tinnitus (LPT and RPT) and healthy controls (HCs) to further explore the lateralization effects of PT using arterial spin labeling (ASL). Methods: ASL data from 21 RPT patients, 17 LPT patients and 21 HCs were reviewed. Voxel-wise analysis and region of interest analysis were performed to explore differences in CBF among the three groups. Tinnitus Handicap Inventory (THI) score and tinnitus duration were obtained from each patient. Results: Voxel-wise analysis showed that the CBF of the left inferior parietal gyrus was increased in both RPT and LPT patients compared with HCs (P < 0…
Implementation of computed tomography angiography (CTA) and computed tomography perfusion (CTP) in Polish guidelines for determination of cerebral ci…
2021
Background: Brain death/death by neurologic criteria (BD/DNC) guidelines are routinely analyzed, compared and updated in the majority of countries and are later implemented as national criteria. At the same time, extensive works have been conducted in order to unify clinical procedures and to validate and implement new technologies into a panel of ancillary tests. Recently evaluated computed tomography angiography and computed tomography perfusion (CTA/CTP) seem to be superior to traditionally used digital subtraction angiography (DSA), transcranial Doppler (TCD) and cerebral perfusion scintigraphy for diagnosis of cerebral circulatory arrest (CCA). In this narrative review, we would like t…
Cerebral Blood Flow Regulation Under the Conditions of Arterial Hypoxia
1978
Pronounced arterial hypoxia induces a decrease of cerebrovascular resistance and an increase of total and regional cerebral blood flow. Under the conditions of normal arterial blood pressure and normal acid base status, the changes of both parameters commence when the oxygen tension in the arterial blood decreases below approximately 50 mm Hg. At the same time, the oxygen tension in the cerebral venous blood reaches values below approximately 28 mm Hg. Different authors [23, 28, 30, 31, 33] reported that cerebral blood flow responses to PaO2 decrease are threshold at these oxygen tensions. The threshold oxygen tension of cerebral venous blood was accorded a special significance because Noel…
Clinical significance of the quantitative and qualitative determination of the cerebral blood flow through the use of isotopes
1966
Es wird über die bisher entwickelten Methoden zur bestimmung der Hirndurchblutung mit radioaktiven Isotopen berichtet, wobei die quantitativen Untersuchungsmethoden hinsichtlich ihrer klinischen Bedeutung den qualitativen gegenübergestellt werden. Während die quantitativen Methoden eine genaue Bestimmung des cerebralen Blutvolumens und damit der Gesamtdurchblutung des Hirns bzw. bestimmter Hirnareale ermöglichen, bieten die qualitativen Untersuchungsmethoden hinsichtlich der klinisch-diagnostischen Aussagekraft besondere Vorteile. Aus der Bestimmung der Zirkulationszeit des Hirns und dem Verlauf der über beiden Hemisphären registrierten Aktivitätskurven lassen sich differenzial-diagnostisch…
Usefulness of Cerebral Oximetry in TBI by NIRS
2021
Measurement of cerebral oximetry by near-infrared spectroscopy provides continuous and non-invasive information about the oxygen saturation of haemoglobin in the central nervous system. This is especially important in the case of patients with traumatic brain injuries. Monitoring of cerebral oximetry in these patients could allow for the diagnosis of inadequate cerebral oxygenation caused by disturbances in cerebral blood flow. It could enable identification of episodes of hypoxia and cerebral ischemia. Continuous bedside measurement could facilitate the rapid diagnosis of intracranial bleeding or cerebrovascular autoregulation disorders and accelerate the implementation of treatment. Howev…