Effects of tromethamine and hyperventilation on brain injury in the cat

1991 ◽  
Vol 74 (1) ◽  
pp. 87-96 ◽  
Author(s):  
Kazuo Yoshida ◽  
Anthony Marmarou

✓ The metabolic brain acidosis after trauma has been thought to be harmful and to contribute to neurological deterioration. Amelioration of the brain acidosis either by systemic buffering agents or by hyperventilation has been proposed as a method of treatment. The objective of this study was to explore with magnetic resonance (MR) spectroscopy the metabolic changes in brain that occur with the use of hyperventilation, THAM (tromethamine; tris[hydroxymethyl]aminomethane), and a combination (THAM and hyperventilation) therapy in experimental fluid-percussion injury. Brain lactate, brain pH, inorganic phosphate (Pi), and adenosine triphosphate levels were measured by 1H and 31P MR spectroscopy. Arterial and cerebrovenous lactate and water content in brain tissue was determined in 29 cats using the specific gravimetric technique. Following injury, the phosphocreatine (PCr)/Pi ratio, which is an index of cerebral energy depletion, decreased to 76% in four untreated animals, to 79% in 11 THAM-treated animals, to 68% in seven animals receiving hyperventilation, and to 66% in seven animals with combination THAM and hyperventilation therapy. The PCr/Pi ratio returned to a normal level in 8 hours in animals treated with THAM and THAM in combination with hyperventilation. The brain lactate index increased to 157% in the hyperventilation group after trauma. In cats receiving THAM plus hyperventilation, the brain lactate index was reduced to 142%, while the minimum rise of 126% was associated with treatment of THAM alone. In the THAM-treatment and combination-treatment groups, the water content of the white and gray matter was significantly decreased compared with that in untreated cat brains. Prolonged hyperventilation provided relative ischemia in brain tissue and promoted more production of brain lactate, no recovery of the PCr/Pi ratio, and no decrease in brain edema. On the other hand, administration of THAM decreased production of brain lactate and brain edema and promoted the recovery of cerebral energy dysfunction. It was found that THAM ameliorates the deleterious effects of hyperventilation by minimizing energy disturbance and that it also decreases brain edema. The authors conclude that THAM may be effective in reducing brain tissue acidosis and helpful as a metabolic stabilizing agent following severe head injury.

1988 ◽  
Vol 69 (5) ◽  
pp. 736-744 ◽  
Author(s):  
Suguru Inao ◽  
Anthony Marmarou ◽  
Geoff D. Clarke ◽  
Bruce J. Andersen ◽  
Panos P. Fatouros ◽  
...  

✓ Lactate dynamics in the brain, cerebrospinal fluid (CSF), and serum were studied in 20 chloralose-anesthetized cats following fluid-percussion trauma. Brain lactate and brain tissue pH were measured by hydrogen-1 and phophorus-31 magnetic resonance spectroscopy. The CSF, arterial, and cerebrovenous serum lactate levels as well as serum glucose concentration were quantified. In the six sham-operated control animals, brain, CSF, cerebrovenous, and arterial lactate levels as well as brain pH remained at normal values. In the five animals in the mild-trauma group (1.6 atm), brain and CSF lactate levels were moderately elevated, although the brain pH and serum lactate content remained at control values. Severe trauma (3.1 atm) in nine cats produced an 82% increase in the brain lactate index and a reduction in brain tissue pH (7.02 ± 0.02 to 6.95 ± 0.02; mean ± standard error of the mean), indicating brain tissue acidosis caused by excessive lactate accumulation. Brain lactate levels reached a peak 1½ hours after severe trauma, then steadily decreased to normal levels by 8 hours posttrauma. Maximum increases of CSF and arterial lactate levels (from 1.4 ± 0.2 to 4.1 ± 0.4 and from 1.6 ± 0.2 to 4.1 to 0.6 mmol/liter, respectively) were observed 15 minutes after trauma, and the values decreased during the next 2 hours. The response was biphasic, with a secondary rise observed in both CSF and serum lactate levels during the remaining 4 hours of the experiment. The difference between the arterial and venous lactate levels (A-Vlact) gradually increased and reached a peak 2 hours postinjury (from −0.05 ± 0.10 to −0.41 ± 0.09 mmol/liter). The results of this study show that the production of lactate in brain tissue, CSF, and blood increased in proportion to the severity of the injury. The observation that lactate levels in blood and CSF are maximum immediately following impact while brain lactate and A-Vlact are gradually increasing suggests that the brain-tissue production of lactate fails to account for the rapid appearance of lactate in CSF and blood. It is speculated that the initial elevation of CSF lactate values reflects the systemic response of trauma, and the secondary rise of CSF lactate levels following severe trauma is due to slow seepage of lactate produced by brain tissue into the CSF space. These studies are the first to describe the temporal profile of brain lactate production and eventual clearance by CSF and blood in fluid-percussion injury. The results emphasize the need for caution in interpreting elevated CSF lactate levels following head injury.


2000 ◽  
Vol 92 (6) ◽  
pp. 1016-1022 ◽  
Author(s):  
Ya Hua ◽  
Guohua Xi ◽  
Richard F. Keep ◽  
Julian T. Hoff

Object. Brain edema formation following intracerebral hemorrhage (ICH) appears to be partly related to erythrocyte lysis and hemoglobin release. Erythrocyte lysis may be mediated by the complement cascade, which then triggers parenchymal injury. In this study the authors examine whether the complement cascade is activated after ICH and whether inhibition of complement attenuates brain edema around the hematoma.Methods. This study was divided into three parts. In the first part, 100 µl of autologous blood was infused into the rats' right basal ganglia, and the animals were killed at 24 and 72 hours after intracerebral infusion. Their brains were tested for complement factors C9, C3d, and clusterin (a naturally occurring complement inhibitor) by using immunohistochemical analysis. In the second part of the study, the rats were killed at 24 or 72 hours after injection of 100 µl of blood. The C9 and clusterin proteins were quantitated using Western blot analysis. In the third part, the rats received either 100 µl of blood or 100 µl of blood plus 10 µg of N-acetylheparin (a complement activation inhibitor). Then they were killed 24 or 72 hours later for measurement of brain water and ion contents. It was demonstrated on Western blot analysis that there had been a sixfold increase in C9 around the hematoma 24 hours after the infusion of 100 µl of autologous blood. Marked perihematomal C9 immunoreactivity was detected at 72 hours. Clusterin also increased after ICH and was expressed in neurons 72 hours later. The addition of N-acetylheparin significantly reduced brain edema formation in the ipsilateral basal ganglia at 24 hours (78.5 ± 0.5% compared with 81.6 ± 0.8% in control animals, p < 0.001) and at 72 hours (80.9 ± 2.2% compared with 83.6 ± 0.9% in control animals, p < 0.05) after ICH.Conclusions. It was found that ICH causes complement activation in the brain. Activation of complement and the formation of membrane attack complex contributes to brain edema formation after ICH. Blocking the complement cascade could be an important step in the therapy for ICH.


2000 ◽  
Vol 93 (4) ◽  
pp. 594-604 ◽  
Author(s):  
Michael Bitzer ◽  
Thomas Nägele ◽  
Beverly Geist-Barth ◽  
Uwe Klose ◽  
Eckardt Grönewäller ◽  
...  

Object. In a prospective study, 28 patients with 32 intracranial meningiomas were examined to determine the role of hydrodynamic interaction between tumor and surrounding brain tissue in the pathogenesis of peritumoral brain edema.Methods. Gadolinium—diethylenetriamine pentaacetic acid (Gd-DPTA), an extracellular contrast agent used for routine clinical imaging, remains strictly extracellular without crossing an intact blood—brain barrier. Therefore, it is well suited for investigations of hydrodynamic extracellular mechanisms in the development of brain edema. Spin-echo T1-weighted magnetic resonance images were acquired before and after intravenous administration of 0.2 mmol/kg Gd-DPTA. Additional T1-weighted imaging was performed 0.6, 3.5, and 6.5 hours later. No significant Gd-DPTA diffused from tumor into peritumoral brain tissue in 12 meningiomas without surrounding brain edema. In contrast, in 17 of 20 meningiomas with surrounding edema, contrast agent in peritumoral brain tissue was detectable after 3.5 hours and 6.5 hours. In three of 20 meningiomas with minimum surrounding edema (< 5 cm3), contrast agent effusion was absent. After 3.5 hours and 6.5 hours strong correlations of edema volume and the maximum distance of contrast spread from the tumor margin into adjacent brain parenchyma (r = 0.84 and r = 0.87, respectively, p < 0.0001) indicated faster effusion in larger areas of edema.Conclusions. The results of this study show that significant contrast agent effusion from the extracellular space of the tumor into the interstitium of the peritumoral brain tissue is only found in meningiomas with surrounding edema. This supports the hypothesis that hydrodynamic processes play an essential role in the pathogenesis of peritumoral brain edema in meningiomas.


1979 ◽  
Vol 51 (1) ◽  
pp. 70-77 ◽  
Author(s):  
Jurjen Gazendam ◽  
K. Gwan Go ◽  
Annie K. van Zanten

✓ Edema fluid isolated from cats with cold-induced brain edema was subjected to analysis of electrolyte content, enzyme activities, colloid osmotic pressure and the radioactivity of intravenously injected 99mTc-labeled albumin. The findings corroborate the essential features of vasogenic edema, such as its origin from the blood plasma, its rapid propagation into the white matter of the brain as contrasted with the delayed spread into gray matter, and its contribution to composition of cerebrospinal fluid. Moreover, the elevated activities of cellular enzymes and K+ content of edema fluid point to the admixture with cellular contents due to the freezing damage.


2000 ◽  
Vol 93 (2) ◽  
pp. 183-193 ◽  
Author(s):  
Anthony Marmarou ◽  
Panos P. Fatouros ◽  
Pal Barzó ◽  
Gennarina Portella ◽  
Masaaki Yoshihara ◽  
...  

Object. The pathogenesis of traumatic brain swelling remains unclear. The generally held view is that brain swelling is caused primarily by vascular engorgement and that edema plays a relatively minor role in the swelling process. The goal of this study was to examine the roles of cerebral blood volume (CBV) and edema in traumatic brain swelling.Methods. Both brain-tissue water and CBV were measured in 76 head-injured patients, and the relative contribution of edema and blood to total brain swelling was determined. Comparable measures of brain-tissue water were obtained in 30 healthy volunteers and CBV in seven volunteers. Brain edema was measured using magnetic resonance imaging, implementing a new technique for accurate measurement of total tissue water. Measurements of CBV in a subgroup of 31 head-injured patients were based on consecutive measures of cerebral blood flow (CBF) obtained using stable xenon and calculation of mean transit time by dynamic computerized tomography scanning after a rapid bolus injection of iodinated contrast material. The mean (± standard deviation) percentage of swelling due to water was 9.37 ± 8.7%, whereas that due to blood was −0.8 ± 1.32%.Conclusions. The results of this study showed that brain edema is the major fluid component contributing to traumatic brain swelling. Moreover, CBV is reduced in proportion to CBF reduction following severe brain injury.


1986 ◽  
Vol 64 (4) ◽  
pp. 643-649 ◽  
Author(s):  
Shizuo Hatashita ◽  
Julian T. Hoff ◽  
Shozo Ishii

✓ Acute arterial hypertension was studied in normal cats to determine its role in the formation of brain edema. Arterial hypertension was induced for 30 minutes by inflation of a balloon catheter situated in the descending aorta. Cerebral edema was evaluated by gross and microscopic observations, tissue water content by wet/dry weights, and blood-brain barrier (BBB) permeability by extravasation of horseradish peroxidase (HRP) and Evans blue dye. For 1 hour after the hypertensive insult, tissue pressure and regional cerebral blood flow (rCBF) were measured from the arterial boundary zone and from a non-boundary region, and intracranial pressure was recorded from the lateral ventricle as ventricular fluid pressure. Focal lesions with increased BBB permeability to Evans blue dye or HRP were usually located symmetrically in the cortex, corresponding to the occipitoparietal parts of the arterial boundary zones. The increase in water content was found only in areas of increased permeability. Tissue pressure increased simultaneously with the abrupt rise in blood pressure, and an increase in rCBF paralleled the elevation of blood pressure. Tissue pressure and rCBF returned to a steady state when blood pressure returned to normal. There were no differences in tissue pressure or rCBF between the arterial boundary zone and the non-boundary zone, even during arterial hypertension. In cerebral hemispheres examined 48 hours after the hypertensive challenge, brain edema had not continued to develop. The data indicate that acute arterial hypertension may produce focal brain edema with increased permeability of the BBB in the cortex of normal brain, particularly in the arterial boundary zones. The authors postulate that increased cerebral blood volume, high intraluminal pressure, and breakthrough of autoregulation play an important role in the formation of hypertensive brain edema.


2005 ◽  
Vol 102 (6) ◽  
pp. 1115-1121 ◽  
Author(s):  
Andrea Kleindienst ◽  
Christos M. Tolias ◽  
Frank D. Corwin ◽  
Christian Müller ◽  
Anthony Marmarou ◽  
...  

Object. After traumatic brain injury (TBI), S100B protein is released by astrocytes. Furthermore, cerebrospinal fluid (CSF) and serum S100B levels have been correlated to outcome. Given that no data exist about the temporal profile of cerebral S100B levels following TBI and their correlation to serum levels, the authors examined whether proton magnetic resonance (MR) spectroscopy is capable of measuring S100B. Methods. Results of in vitro proton MR spectroscopy experiments (2.35-tesla magnet, 25 G/cm, point-resolved spatially localized spectroscopy) revealed an S100B-specific peak at 4.5 ppm and confirmed a positive correlation between different S100B concentrations (10 nM–1 µM) and the area under the curve (AUC) for the S100B peak (r = 0.991, p < 0.001). Thereafter, proton MR spectroscopy was performed in male Sprague—Dawley rats (7 × 5 × 5—mm voxel in each hemisphere, TR 3000 msec, TE 30 msec, 256 acquisitions). Exogenously increased CSF S100B levels (∼ 200 ng/ml) through the intraventricular infusion of S100B increased the AUC of the S100B peak from 0.06 ± 0.02 to 0.44 ± 0.06 (p < 0.05), whereas serum S100B levels remained normal. Two hours after lateral fluid-percussion injury, serum S100B levels increased to 0.61 ± 0.09 ng/ml (p < 0.01) and rapidly returned to normal levels, whereas the AUC of the S100B peak increased to 0.19 ± 0.04 at 2 hours postinjury and 0.41 ± 0.07 (p < 0.05) on Day 5 postinjury. Conclusions. Proton MR spectroscopy proves a strong correlation between the AUC of the S100B peak and S100B concentrations. Following experimental TBI, serum S100B levels increased for only a very short period, whereas cerebral S100B levels were increased up to Day 5 postinjury. Given that experimental data indicate that S100B is actively released following TBI, proton MR spectroscopy may represent a new tool to identify increased cerebral S100B levels in patients after injury, thus allowing its biological function to be better understood.


1974 ◽  
Vol 40 (6) ◽  
pp. 706-716 ◽  
Author(s):  
Yukitaka Ushio ◽  
Toru Hayakawa ◽  
Heitaro Mogami

✓ Malignant gliomas were induced in strain ddN mice by intracerebral implantation of a 20-methylcholanthrene pellet. The uptake and distribution of tritiated methotrexate (MTX-3H) in the tumor were investigated by radioactive assay and radioautography after single intravenous or intrathecal injections. By either route, a large amount of MTX-3H was taken up by gliomas, and a significantly higher concentration was observed in tumor than in the brain tissue. At 24 hours after intrathecal administration, the uptake of MTX-3H by gliomas exceeded that achieved after intravenous injection, although the drug dosage in the latter was 10 times that in the former.


2004 ◽  
Vol 101 (2) ◽  
pp. 323-329 ◽  
Author(s):  
Michael Reinert ◽  
Benoit Schaller ◽  
Hans Rudolf Widmer ◽  
Rolf Seiler ◽  
Ross Bullock

Object. Severe traumatic brain injury (TBI) imposes a huge metabolic load on brain tissue, which can be summarized initially as a state of hypermetabolism and hyperglycolysis. In experiments O2 consumption has been shown to increase early after trauma, especially in the presence of high lactate levels and forced O2 availability. In recent clinical studies the effect of increasing O2 availability on brain metabolism has been analyzed. By their nature, however, clinical trauma models suffer from a heterogeneous injury distribution. The aim of this study was to analyze, in a standardized diffuse brain injury model, the effect of increasing the fraction of inspired O2 on brain glucose and lactate levels, and to compare this effect with the metabolism of the noninjured sham-operated brain. Methods. A diffuse severe TBI model developed by Foda and Maramarou, et al., in which a 420-g weight is dropped from a height of 2 m was used in this study. Forty-one male Wistar rats each weighing approximately 300 g were included. Anesthesized rats were monitored by placing a femoral arterial line for blood pressure and blood was drawn for a blood gas analysis. Two time periods were defined: Period A was defined as preinjury and Period B as postinjury. During Period B two levels of fraction of inspired oxygen (FiO2) were studied: air (FiO2 0.21) and oxygen (FiO2 1). Four groups were studied including sham-operated animals: air-air-sham (AAS); air-O2-sham (AOS); air-air-trauma (AAT); and air-O2-trauma (AOT). In six rats the effect of increasing the FiO2 on serum glucose and lactate was analyzed. During Period B lactate values in the brain determined using microdialysis were significantly lower (p < 0.05) in the AOT group than in the AAT group and glucose values in the brain determined using microdialysis were significantly higher (p < 0.04). No differences were demonstrated in the other groups. Increasing the FiO2 had no significant effect on the serum levels of glucose and lactate. Conclusions. Increasing the FiO2 influences dialysate glucose and lactate levels in injured brain tissue. Using an FiO2 of 1 influences brain metabolism in such a way that lactate is significantly reduced and glucose significantly increased. No changes in dialysate glucose and lactate values were found in the noninjured brain.


1987 ◽  
Vol 67 (1) ◽  
pp. 88-92 ◽  
Author(s):  
Kenneth Shapiro ◽  
Ira J. Kohn ◽  
Futoshi Takei ◽  
Corinna Zee

✓ Intracranial pressure (ICP) was measured simultaneously at multiple sites in cats to determine if transmantle pressure gradients were present in progressive hydrocephalus. The cats underwent craniectomy and intracisternal injection of kaolin; 4 to 9 weeks later ICP was measured at the ventricle, cisterna magna, and convexity subarachnoid space, and in the brain tissue and the sagittal sinus. In 13 cats in which ventricular size conformed to previously established norms for duration of hydrocephalus, there were no demonstrable gradients of pressure at any of the sites of measurement according to one-way analysis of variance (p > 0.05). The mean (± standard error of the mean) peak and trough pressures (in mm Hg) at each site were: ventricle, 12.7 ± 0.7 and 12.0 ± 0.6; cisterna magna, 12.9 ± 0.8 and 12.3 ± 0.7; subarachnoid space, 12.7 ± 0.8 and 12.1 ± 0.7; brain tissue, 12.9 ± 0.9 and 12.4 ± 0.9; and sagittal sinus, 13.1 ± 0.8 and 11.9 ± 0.8. These results indicate that ventricular expansion can progress without measurable transmantle pressure gradients.


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