Phenylephrine or Ephedrine for Intraoperative Hypotension? Consider the Cerebral Microcirculation

2021 ◽  
Author(s):  
Paul S. García ◽  
Charles H. Brown
Author(s):  
Enrico D.F. Motti ◽  
Hans-Georg Imhof ◽  
Gazi M. Yasargil

Physiologists have devoted most attention in the cerebrovascular tree to the arterial side of the circulation which has been subdivided in three levels: 1) major brain arteries which keep microcirculation constant despite changes in perfusion pressure; 2) pial arteries supposed to be effectors regulating microcirculation; 3) intracerebral arteries supposed to be deprived of active cerebral blood flow regulating devices.The morphological search for microvascular effectors in the cerebrovascular bed has been elusive. The opaque substance of the brain confines in vivo investigation to the superficial pial arteries. Most morphologists had to limit their observation to the random occurrence of a favorable site in the practically two-dimensional thickness of diaphanized histological sections. It is then not surprising most investigators of the cerebral microcirculation refer to an homogeneous network of microvessels interposed between arterioles and venules.We have taken advantage of the excellent depth of focus afforded by the scanning electron microscope (SEM) to investigate corrosion casts obtained injecting a range of experimental animals with a modified Batson's acrylic mixture.


Author(s):  
Junyuan Wu ◽  
Zhiwei Li ◽  
Wei Yuan ◽  
Qiang Zhang ◽  
Yong Liang ◽  
...  

BACKGROUND: Shenfu injection (SFI) is a traditional Chinese herbal medicine which has been clinically used for treatment of septic shock and cardiac shock. The aim of this study was to clarify effects of SFI on cerebral microcirculation and brain injury after hemorrhagic shock (HS). METHODS: Twenty-one domestic male Beijing Landrace pigs were randomly divided into three groups: SFI group (SFI, n = 8), saline group (SA, n = 8) or sham operation group (SO, n = 5). In the SFI group, animals were induced to HS by rapid bleeding to a mean arterial pressure of 40 mmHg within 10 minutes and maintained at 40±3 mmHg for 60 minutes. Volume resuscitation (shed blood and crystalloid) and SFI were given after 1 hour of HS. In the SA group, animals received the same dose of saline instead of SFI. In the SO group, the same surgical procedure was performed but without inducing HS and volume resuscitation. The cerebral microvascular flow index (MFI), nitric oxide synthase (NOS) expression, aquaporin-4 expression, interleukin-6, tumor necrosis factor-α (TNF-α) and ultrastructural of microvascular endothelia were measured. RESULTS: Compared with the SA group, SFI significantly improved cerebral MFI after HS. SFI up regulated cerebral endothelial NOS expression, but down regulated interleukin-6, TNF-α, inducible NOS and aquaporin-4 expression compared with the SA group. The cerebral microvascular endothelial injury and interstitial edema in the SFI group were lighter than those in the SA group. CONCLUSIONS: Combined application of SFI with volume resuscitation after HS can improve cerebral microcirculation and reduce brain injury.


Author(s):  
Diana Londoño ◽  
Adriana Marques ◽  
Diego Cadavid

1991 ◽  
Vol 17 (Supplement 3) ◽  
pp. S15-S18 ◽  
Author(s):  
Roman L. Haberl ◽  
Pamla J. Decker ◽  
Axel Piepgras ◽  
Karl Einhäupl

1998 ◽  
Vol 12 (3) ◽  
pp. 321-323 ◽  
Author(s):  
Adrian K. Dashfield ◽  
William J. Farrington ◽  
Jeremy A. Langton ◽  
Simon Ashley

1988 ◽  
Vol 8 (2) ◽  
pp. 254-261 ◽  
Author(s):  
Ralph G. Dacey ◽  
John E. Bassett ◽  
Masakazu Takayasu

The effect of vasoactive peptides on vascular smooth muscle in the cerebral microcirculation was examined using an isolated intracerebral arteriole preparation. Extraluminally applied vasoactive intestinal peptide (VIP) dilated the spontaneous tone of intracerebral arterioles to 118.9 ± 3.1% of control diameter at pH 7.30, with an EC50 of 7.27 × 10−8 M. Similar degrees of dilation to VIP were seen in vessels preconstricted by changing bath solution to pH 7.60. Substance P had no effect on vessel diameter at pH 7.30. However, in vessels precontracted by pH 7.60, significant dose-dependent dilation was observed with an EC50 of 2.55 × 10−10 M. Neuropeptide constricted intracerebral arterioles to 8l.22 ± 2.7% of control diameter, with an EC50 of 6.23 × 10−10 M. Bradykinin dilated intracerebral arterioles at pH 7.30 and pH 7.60 to 130 ± 3.0% of control diameter. VIP and bradykinin are potent vasodilators of intracerebral arterioles. Neuropeptide Y is a vasoconstrictor. The effect of substance P appeared to be either pH-dependent or dependent on some degree of precontraction by another agonist, but no effect on vessel diameter was seen at pH 7.30.


2021 ◽  
Vol Publish Ahead of Print ◽  
Author(s):  
Shara I. Feld ◽  
Daniel S. Hippe ◽  
Ljubomir Miljacic ◽  
Nayak L. Polissar ◽  
Shu-Fang Newman ◽  
...  

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