scholarly journals Cerebral blood flow measured with diffusing wave spectroscopy during anesthesia

2018 ◽  
Author(s):  
Markus Belau ◽  
Wolfgang Scheffer ◽  
Georg Maret
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Patient Safety ◽  
Cerebral Blood Flow ◽  
Body Temperature ◽  
Clinical Settings ◽  
Diffusing Wave Spectroscopy ◽  
Permanent Damage ◽  
Routine Basis ◽  
The Brain

AbstractThe adequate perfusion of the brain is of utmost importance where already short periods of hypoperfusion may lead to permanent damage. In order to increase patient safety the cerebral blood flow should be monitored in clinical settings during situations, such as anesthesia, where the perfusion might be disturbed. The cerebral blood flow is however not monitored on a routine basis during anesthesia. Diffusing wave spectroscopy is a relative novel optical method that non-invasively measures changes in cerebral blood flow. Here we report changes in cerebral blood flow associated with a delayed cardiac output, a change in isoflurane concentration and body temperature observed during general anesthesia with isoflurane in pigeons.

Cerebral Blood Flow in the Rat

1958 ◽  
Vol 193 (2) ◽  
pp. 272-274 ◽  
Author(s):  
Leo A. Sapirstein ◽  
Gordon E. Hanusek
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Cerebral Blood Flow ◽  
Intravenous Injection ◽  
Extraction Ratio ◽  
Female Rats ◽  
Perfusion Rate ◽  
Single Intravenous Injection ◽  
The Brain ◽  
Fractional Uptake

The cerebral uptake of iodoantipyrine (I131) was measured in anesthetized rats as a function of time after a single intravenous injection. The cerebral content stabilized in 7–9 seconds and remained constant for 64 seconds indicating that the brain and body had the same extraction ratio for the label. The cerebral blood flow fraction therefore corresponded to the fractional uptake of iodoantipyrine by the brain. The cerebral blood flow was calculated as the product of the cardiac output and the cerebral flow fraction. The perfusion rate of the brain was found to be 0.51 ml/gm/min. in female rats.

scholarly journals Distribution of cardiac output to the brain across the adult lifespan

2016 ◽  
Vol 37 (8) ◽  
pp. 2848-2856 ◽  
Author(s):  
Chang-Yang Xing ◽  
Takashi Tarumi ◽  
Jie Liu ◽  
Yinan Zhang ◽  
Marcel Turner ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Blood Flow ◽  
Cardiac Output ◽  
Cerebral Blood Flow ◽  
Body Mass ◽  
Pulse Wave ◽  
Adult Lifespan ◽  
Output Ratio ◽  
The Brain ◽  
Distribution Of Cardiac Output

A widely accepted dogma is that about 15–20% of cardiac output is received by the brain in healthy adults under resting conditions. However, it is unclear if the distribution of cardiac output directed to the brain alters across the adult lifespan and is modulated by sex or other hemodynamic variables. We measured cerebral blood flow/cardiac output ratio index in 139 subjects (88 women, age 21–80 years) using phase-contrast magnetic resonance imaging and echocardiography. Body mass index, cardiac systolic function (eject fraction), central arterial stiffness (carotid-femoral pulse wave velocity), arterial pressure, heart rate, physical fitness (VO2 max), and total brain volume were measured to assess their effects on the cardiac output–cerebral blood flow relationship. Cerebral blood flow/cardiac output ratio index decreased by 1.3% per decade associated with decreases in cerebral blood flow ( P < 0.001), while cardiac output remained unchanged. Women had higher cerebral blood flow, lower cardiac output, and thus higher cerebral blood flow/cardiac output ratio index than men across the adult lifespan. Age, body mass index, carotid-femoral pulse wave velocity, and arterial pressure all had negative correlations with cerebral blood flow and cerebral blood flow/cardiac output ratio index ( P < 0.05). Multivariable analysis adjusted for sex, age showed that only body mass index was negatively associated with cerebral blood flow/cardiac output ratio index (β = −0.33, P < 0.001). These findings demonstrated that cardiac output distributed to the brain has sex differences and decreases across the adult lifespan and is inversely associated with body mass index.

Vorläufige Ergebnisse von 99mTc-HMPAO-SPECT-Untersuchungen bei endogenen Psychosen

1989 ◽  
Vol 28 (03) ◽  
pp. 88-91
Author(s):  
J. Schröder ◽  
H. Henningsen ◽  
H. Sauer ◽  
P. Georgi ◽  
K.-R. Wilhelm
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Regional Cerebral Blood Flow ◽  
Regions Of Interest ◽  
Post Mortem ◽  
Regional Cerebral Blood ◽  
Hmpao Spect ◽  
Endogenous Psychoses ◽  
The Brain ◽  
99Mtc Hmpao

18 psychopharmacologically treated patients (7 schizophrenics, 5 schizoaffectives, 6 depressives) were studied using 99mTc-HMPAO-SPECT of the brain. The regional cerebral blood flow was measured in three transversal sections (infra-/supraventricular, ventricular) within 6 regions of interest (ROI) respectively (one frontal, one parietal and one occipital in each hemisphere). Corresponding ROIs of the same section in each hemisphere were compared. In the schizophrenics there was a significantly reduced perfusion in the left frontal region of the infraventricular and ventricular section (p < 0.02) compared with the data of the depressives. The schizoaffectives took an intermediate place. Since the patients were treated with psychopharmaca, the result must be interpreted cautiously. However, our findings seem to be in accordance with post-mortem-, CT- and PET-studies presented in the literature. Our results suggest that 99mTc-HMPAO-SPECT may be helpful in finding cerebral abnormalities in endogenous psychoses.

Neuroimaging in Drug Discovery and Development: Paradigms for Accelerating New Drug Availability

2001 ◽  
Vol 14 (5) ◽  
pp. 407-415
Author(s):  
John T. Metz ◽  
Malcolm D. Cooper ◽  
Terry F. Brown ◽  
Leann H. Kinnunen ◽  
Declan J. Cooper
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Glucose Metabolism ◽  
Phase Ii ◽  
New Drugs ◽  
Central Effects ◽  
Drug Discovery And Development ◽  
Psychological Tasks ◽  
The Brain ◽  
Phase Iv

The process of discovering and developing new drugs is complicated. Neuroimaging methods can facilitate this process. An analysis of the conceptual bases and practical limitations of different neuroimaging modalities reveals that each technique can best address different kinds of questions. Radioligand studies are well suited to preclinical and Phase II questions when a compound is known or suspected to affect well-understood mechanisms; they are also useful in Phase IV to characterize effective agents. Cerebral blood flow studies can be extremely useful in evaluating the effects of a drug on psychological tasks (mostly in Phase IV). Glucose metabolism studies can answer the simplest questions about whether a compound affects the brain, where, and how much. Such studies are most useful in confirming central effects (preclinical and early clinical phases), in determining effective dose ranges (Phase II), and in comparing different drugs (Phase IV).

Control of Blood Pressure and the Distribution of Blood Flow

1991 ◽  
Vol 7 (S1) ◽  
pp. 79-84 ◽  
Author(s):  
Hans T. Versmold
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Cardiac Output ◽  
Peripheral Resistance ◽  
Systemic Blood Pressure ◽  
Adrenergic Innervation ◽  
Systemic Blood ◽  
Low Cardiac Output ◽  
Neurohumoral Control ◽  
The Brain

Systemic blood pressure (BP) is the product of cardiac output and total peripheral resistance. Cardiac output is controlled by the heart rate, myocardial contractility, preload, and afterload. Vascular resistance (vascular hindrance × viscosity) is under local autoregulation and general neurohumoral control through sympathetic adrenergic innervation and circulating catecholamines. Sympathetic innovation predominates in organs receivingflowin excess of their metabolic demands (skin, splanchnic organs, kidney), while innervation is poor and autoregulation predominates in the brain and heart. The distribution of blood flow depends on the relative resistances of the organ circulations. During stress (hypoxia, low cardiac output), a raise in adrenergic tone and in circulating catecholamines leads to preferential vasoconstriction in highly innervated organs, so that blood flow is directed to the brain and heart. Catecholamines also control the levels of the vasoconstrictors renin, angiotensin II, and vasopressin. These general principles also apply to the neonate.

Effects of Cytoflavin and Neuronol on Morphological Changes in the Brain and Survival of Rats with Ischemic Disturbances in Cerebral Blood Flow

2004 ◽  
Vol 137 (4) ◽  
pp. 411-414 ◽  
Author(s):  
V. V. Bulon ◽  
I. B. Krylova ◽  
N. R. Evdokimova ◽  
A. L. Kovalenko ◽  
L. E. Alekseeva ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Morphological Changes ◽  
The Brain

scholarly journals Use of 19F NMR Spectroscopy for Measurement of Cerebral Blood Flow: A Comparative Study Using Microspheres

1989 ◽  
Vol 9 (6) ◽  
pp. 886-891 ◽  
Author(s):  
David Barranco ◽  
Leslie N. Sutton ◽  
Sandra Florin ◽  
Joel Greenberg ◽  
Teresa Sinnwell ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Arterial Blood ◽  
Radioactive Microsphere ◽  
Low Concentrations ◽  
Cat Brain ◽  
Nmr Techniques ◽  
High Concentrations ◽  
Washout Curves ◽  
The Brain

19F NMR was used to determine washout curves of an inert, diffusible gas (CHF3) from the cat brain. The cerebral blood flow was estimated from a bi- or tri-phasic fit to the deconvoluted wash-out curve, using the Kety-Schmidt approach. Cerebral blood flow values determined by 19F NMR show the expected responsiveness to alterations in Paco2, but are approximately 28% lower than cerebral blood flow values determined simultaneously by radioactive microsphere techniques. High concentrations of CHF3 have little effect on intracranial pressure, mean arterial blood pressure or Paco2, but cause small changes in the blood flow to certain regions of the brain. We conclude that 19F NMR techniques utilizing low concentrations of CHF3 have potential for the noninvasive measurement of cerebral blood flow.

Effect of Prostacyclin on Cardiac Output and Cerebral Blood Flow

1982 ◽  
Vol 62 (2) ◽  
pp. 17P-17P ◽  
Author(s):  
P.J. Cook ◽  
C.G. Maidment ◽  
I.M. James ◽  
R.A. Hutton ◽  
P. Dandona
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Cerebral Blood Flow

Cerebral blood flow and evoked potentials during Cushing response in sheep

1989 ◽  
Vol 256 (3) ◽  
pp. H779-H788
Author(s):  
R. C. Koehler ◽  
J. E. Backofen ◽  
R. W. McPherson ◽  
M. D. Jones ◽  
M. C. Rogers ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Cerebral Blood Flow ◽  
Intracranial Pressure ◽  
Arterial Pressure ◽  
Evoked Potentials ◽  
Aortic Pressure ◽  
Base Line ◽  
Auditory Evoked Responses ◽  
Cushing Response

We determined how alterations in systemic hemodynamics, characteristic of the Cushing response, are related to changes in cerebral blood flow (CBF), cerebral metabolic rate of O2 (CMRO2), and brain electrical conductive function, as assessed by somatosensory-evoked potentials (SEP) and brain stem auditory-evoked responses (BAER). In three groups of eight pentobarbital-anesthetized sheep, intracranial pressure was gradually elevated to within 50, 25, or 0 mmHg of base-line mean arterial pressure and then held constant for 40 min by intraventricular infusion of mock cerebrospinal fluid. Microsphere-determined CBF fell when cerebral perfusion pressure was less than 50 mmHg. CMRO2 fell when CBF fell greater than 30-40%. Mean aortic pressure and cardiac output increased when CBF fell greater than 40%, i.e., at approximately the level at which CMRO2 fell. Furthermore, the magnitude of the increase in arterial pressure and cardiac output correlated with the reduction of CMRO2. SEP latency did not increase unless CBF fell greater than 55-65%, corresponding to a 20-30% reduction of CMRO2. Increased latency of BAER wave V was associated with a fall in midbrain blood flow of greater than 65-70%. Thus increase in SEP and BAER latencies required reductions of flow greater than those required to elicit a systemic response. This demonstrates that there is a range of intracranial pressure over which the increase in arterial pressure preserves sufficient CBF to sustain minimal electrical conductive function. The best predictor of the onset and magnitude of the Cushing response in adult sheep is the decrease in CMRO2.

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