Regional Cerebral Blood Flow and Tissue pO2 after Focal Trauma: Effects of Isoflurane and Fentanyl1

Author(s):  
R. Murr ◽  
S. Berger ◽  
L. Sch�rer ◽  
A. Baethmann
1992 ◽  
Vol 263 (2) ◽  
pp. R221-R225 ◽  
Author(s):  
P. E. Bickler ◽  
D. Julian

Very low arterial CO2 tension (PaCO2) experienced by birds during high-altitude flight may result in cerebral vasoconstriction and reduced cerebral O2 delivery. To examine this possibility, we measured regional cerebral blood flow (CBF) and tissue PO2 in pentobarbital-anesthetized geese (Anser domesticus). Twenty-five-micrometer Teflon-coated platinum electrodes for H2-clearance measurements of local blood flow or tissue PO2 were implanted in the cerebral cortex in 11 geese. Tissue H2 and O2 were measured by voltage clamping the electrodes at +0.30 and -0.5 V, respectively. Washout kinetics of H2 gas administered via unidirectional lung ventilation was used to calculate local blood flow for those electrodes exhibiting one- or two-compartment washout kinetics of H2 (128 of 296 washouts in 31 electrodes). PaCO2 was controlled between 8 and 55 mmHg by altering pulmonary gas flow or by adjusting inspired PCO2. CBF decreased as PaCO2 fell from 50 to 20 mmHg but did not decrease further as PaCO2 was reduced below 20 mmHg. CBF was uniformly distributed in different regions of the cortex. Despite the plateau in CBF during severe hypocapnia, tissue PO2 continued to decline as PaCO2 fell below 20 mmHg. Severe alkalosis may limit cerebral O2 delivery in birds during high-altitude flight.


2014 ◽  
Author(s):  
Scott Harcourt ◽  
Daniel G. Amen ◽  
Kristin C. Willeumier ◽  
Charles J. Golden

1989 ◽  
Vol 28 (03) ◽  
pp. 88-91
Author(s):  
J. Schröder ◽  
H. Henningsen ◽  
H. Sauer ◽  
P. Georgi ◽  
K.-R. Wilhelm

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.


1987 ◽  
Vol 26 (05) ◽  
pp. 192-197 ◽  
Author(s):  
T. Kreisig ◽  
P. Schmiedek ◽  
G. Leinsinger ◽  
K. Einhäupl ◽  
E. Moser

Using the 133Xe-DSPECT technique, quantitative measurements of regional cerebral blood flow (rCBF) were performed before and after provocation with acetazolamide (Diamox) i. v. in 32 patients without evidence of brain disease (normals). In 6 cases, additional studies were carried out to establish the time of maximal rCBF increase which was found to be approximately 15 min p. i. 1 g of Diamox increases the rCBF from 58 ±8 at rest to 73±5 ml/100 g/min. A Diamox dose of 2 g (9 cases) causes no further rCBF increase. After plotting the rCBF before provocation (rCBFR) and the Diamox-induced rCBF increase (reserve capacity, Δ rCBF) the regression line was Δ rCBF = −0,6 x rCBFR +50 (correlation coefficient: r = −0,77). In normals with relatively low rCBF values at rest, Diamox increases the reserve capacity much more than in normals with high rCBF values before provocation. It can be expected that this concept of measuring rCBF at rest and the reserve capacity will increase the sensitivity of distinguishing patients with reversible cerebrovascular disease (even bilateral) from normals.


2017 ◽  
Vol 31 (7) ◽  
pp. 553-562
Author(s):  
Nobuhiro Yada ◽  
Hideo Onishi ◽  
Masahiro Miyai ◽  
Kentarou Ozasa ◽  
Takashi Katsube ◽  
...  

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