scholarly journals The underestimated effect of normobaric hyperoxia on cerebral blood flow and its relationship to neuroprotection

Brain ◽  
2016 ◽  
Vol 139 (11) ◽  
pp. e62-e62 ◽  
Author(s):  
Laurent Chazalviel ◽  
Hélène N. David ◽  
Benoit Haelewyn ◽  
Jean-Eric Blatteau ◽  
Nicolas Vallée ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Normobaric Hyperoxia

A prospective, randomized clinical trial to compare the effect of hyperbaric to normobaric hyperoxia on cerebral metabolism, intracranial pressure, and oxygen toxicity in severe traumatic brain injury

2010 ◽  
Vol 112 (5) ◽  
pp. 1080-1094 ◽  
Author(s):  
Sarah B. Rockswold ◽  
Gaylan L. Rockswold ◽  
David A. Zaun ◽  
Xuewei Zhang ◽  
Carla E. Cerra ◽  
...  
Keyword(s):  
Traumatic Brain Injury ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Intracranial Pressure ◽  
Brain Tissue ◽  
Cerebral Metabolism ◽  
Treatment Session ◽  
Control Group ◽  
Normobaric Hyperoxia ◽  
The Brain

Object Oxygen delivered in supraphysiological amounts is currently under investigation as a therapy for severe traumatic brain injury (TBI). Hyperoxia can be delivered to the brain under normobaric as well as hyperbaric conditions. In this study the authors directly compare hyperbaric oxygen (HBO2) and normobaric hyperoxia (NBH) treatment effects. Methods Sixty-nine patients who had sustained severe TBIs (mean Glasgow Coma Scale Score 5.8) were prospectively randomized to 1 of 3 groups within 24 hours of injury: 1) HBO2, 60 minutes of HBO2 at 1.5 ATA; 2) NBH, 3 hours of 100% fraction of inspired oxygen at 1 ATA; and 3) control, standard care. Treatments occurred once every 24 hours for 3 consecutive days. Brain tissue PO2, microdialysis, and intracranial pressure were continuously monitored. Cerebral blood flow (CBF), arteriovenous differences in oxygen, cerebral metabolic rate of oxygen (CMRO2), CSF lactate and F2-isoprostane concentrations, and bronchial alveolar lavage (BAL) fluid interleukin (IL)–8 and IL-6 assays were obtained pretreatment and 1 and 6 hours posttreatment. Mixed-effects linear modeling was used to statistically test differences among the treatment arms as well as changes from pretreatment to posttreatment. Results In comparison with values in the control group, the brain tissue PO2 levels were significantly increased during treatment in both the HBO2 (mean ± SEM, 223 ± 29 mm Hg) and NBH (86 ± 12 mm Hg) groups (p < 0.0001) and following HBO2 until the next treatment session (p = 0.003). Hyperbaric O2 significantly increased CBF and CMRO2 for 6 hours (p ≤ 0.01). Cerebrospinal fluid lactate concentrations decreased posttreatment in both the HBO2 and NBH groups (p < 0.05). The dialysate lactate levels in patients who had received HBO2 decreased for 5 hours posttreatment (p = 0.017). Microdialysis lactate/pyruvate (L/P) ratios were significantly decreased posttreatment in both HBO2 and NBH groups (p < 0.05). Cerebral blood flow, CMRO2, microdialysate lactate, and the L/P ratio had significantly greater improvement when a brain tissue PO2 ≥ 200 mm Hg was achieved during treatment (p < 0.01). Intracranial pressure was significantly lower after HBO2 until the next treatment session (p < 0.001) in comparison with levels in the control group. The treatment effect persisted over all 3 days. No increase was seen in the CSF F2-isoprostane levels, microdialysate glycerol, and BAL inflammatory markers, which were used to monitor potential O2 toxicity. Conclusions Hyperbaric O2 has a more robust posttreatment effect than NBH on oxidative cerebral metabolism related to its ability to produce a brain tissue PO2 ≥ 200 mm Hg. However, it appears that O2 treatment for severe TBI is not an all or nothing phenomenon but represents a graduated effect. No signs of pulmonary or cerebral O2 toxicity were present.

scholarly journals Normobaric hyperoxia improves cerebral blood flow and oxygenation, and inhibits peri-infarct depolarizations in experimental focal ischaemia

Brain ◽  
2007 ◽  
Vol 130 (6) ◽  
pp. 1631-1642 ◽  
Author(s):  
Hwa Kyoung Shin ◽  
Andrew K. Dunn ◽  
Phillip B. Jones ◽  
David A. Boas ◽  
Eng H. Lo ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Normobaric Hyperoxia ◽  
Focal Ischaemia

Alterations in regional decreased cerebral blood flow in patients with irritable bowel syndrome-A PET imaging study

2001 ◽  
Vol 120 (5) ◽  
pp. A637-A637
Author(s):  
Y RINGEL ◽  
D DROSSMAN ◽  
T TURKINGTON ◽  
B BRADSHAW ◽  
R COLEMAN ◽  
...  
Keyword(s):  
Blood Flow ◽  
Irritable Bowel Syndrome ◽  
Cerebral Blood Flow ◽  
Pet Imaging ◽  
Imaging Study ◽  
Irritable Bowel

Patterns of Cerebral Blood Flow and Systemic Hemodynamics During Arithmetic Processing

2008 ◽  
Vol 22 (2) ◽  
pp. 81-90 ◽  
Author(s):  
Natalie Werner ◽  
Neval Kapan ◽  
Gustavo A. Reyes del Paso
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Time Course ◽  
Doppler Sonography ◽  
Transcranial Doppler Sonography ◽  
Systemic Hemodynamics ◽  
Heart Period ◽  
Blood Flow Velocities ◽  
Flow Velocities

The present study explored modulations in cerebral blood flow and systemic hemodynamics during the execution of a mental calculation task in 41 healthy subjects. Time course and lateralization of blood flow velocities in the medial cerebral arteries of both hemispheres were assessed using functional transcranial Doppler sonography. Indices of systemic hemodynamics were obtained using continuous blood pressure recordings. Doppler sonography revealed a biphasic left dominant rise in cerebral blood flow velocities during task execution. Systemic blood pressure increased, whereas heart period, heart period variability, and baroreflex sensitivity declined. Blood pressure and heart period proved predictive of the magnitude of the cerebral blood flow response, particularly of its initial component. Various physiological mechanisms may be assumed to be involved in cardiovascular adjustment to cognitive demands. While specific contributions of the sympathetic and parasympathetic systems may account for the observed pattern of systemic hemodynamics, flow metabolism coupling, fast neurogenic vasodilation, and cerebral autoregulation may be involved in mediating cerebral blood flow modulations. Furthermore, during conditions of high cardiovascular reactivity, systemic hemodynamic changes exert a marked influence on cerebral blood perfusion.

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