Cerebral Carbohydrate Metabolism in Man During Halothane Anesthesia

Cohen, Peter J.; Wollman, Harry; Alexander, S. Craighead; Chase, P. E.; Behar, Marjam G.

doi:10.1097/00000542-196403000-00013

Cited by 97 publications

(27 citation statements)

References 0 publications

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“…In addition to visual stimulation, we use moderate hypercapnia as a reference stimulus, as previously proposed by Bandettini et al (10), Davis et al (11,12), and Schwarzbauer et al (13,14). Moderate hypercapnia provides a tool for selectively manipulating cerebral hemodynamics without significantly affecting oxidative metabolism (15,16). At a suitable inspiratory concentration of carbon dioxide, the values of the hemodynamic parameters are approximately the same as under visual stimulation.…”

Section: Introductionmentioning

confidence: 99%

Investigating the dependence of BOLD contrast on oxidative metabolism

Schwarzbauer¹,

Heinke²

1999

Magn. Reson. Med.

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Most functional magnetic resonance imaging (fMRI) studies are based on measuring the changes in the blood oxygenation level-dependent (BOLD) contrast that arise from a complex interplay between cerebral hemodynamics and oxidative metabolism. To separate these effects, we consecutively applied two different stimuli: visual stimulation (black/white checkerboard alternating with a frequency of 8 Hz) and hypercapnia (inspiration of 5% CO 2 ). Changes in cerebral blood flow (⌬CBF) and the effective transverse relaxation time (T * 2 ) were measured in an interleaved manner by combining a previously described spinlabeling technique with BOLD-based fMRI. In six healthy volunteers, T * 2 was significantly longer during hypercapnia than during visual stimulation, whereas the corresponding ⌬CBF values were the same at the given level of significance (P F 0.01). This finding is explained by a significant increase in oxygen consumption under visual stimulation. The average T * 2 changes in the visual cortex related to cerebral hemodynamics and oxidative metabolism were 10.6 ؎ 3.0% and ؊4.7 ؎ 1.2%, respectively, resulting in a net increase of 5.9 ؎ 2.3%. Although the hemodynamic effect is dominant, the increase in oxidative metabolism gives rise to a significant decrease in BOLD contrast. The calculated average change in the cerebral metabolic rate of oxygen (CMRO 2

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Section: Introductionmentioning

confidence: 99%

Investigating the dependence of BOLD contrast on oxidative metabolism

Schwarzbauer¹,

Heinke²

1999

Magn. Reson. Med.

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“…A critical mechanism by which therapeutic temperature modulation confers neuroprotection is by reducing the cerebral metabolic rate by up to 15% for every 1°C reduction in core body temperature. 23,24 However, these reductions in cerebral metabolism can be offset when shivering is uncontrolled. The BSAS allows clinicians to identify and quantify moderate or severe levels of shivering (scores of 2 or 3, respectively) that are associated with clinically important increases in systemic metabolism.…”

Section: Badjatia Et Al Metabolic Impact Of Shivering 3245mentioning

confidence: 99%

Metabolic Impact of Shivering During Therapeutic Temperature Modulation

Badjatia

Strongilis

Gordon

et al. 2008

Stroke

284

163

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Background and Purpose-Therapeutic temperature modulation is widely used in neurocritical care but commonly causes shivering, which can hamper the cooling process and result in increases in systemic metabolism. We sought to validate a grading scale to assist in the monitoring and control of shivering. Methods-A simple 4-point Bedside Shivering Assessment Scale was validated against continuous assessments of resting energy expenditure, oxygen consumption, and carbon dioxide production as measured by indirect calorimetry. Therapeutic temperature modulation for fever control or the induction of hypothermia was achieved with the use of a surface or endovascular device. Expected energy expenditure was calculated using the Harris-Benedict equation. A hypermetabolic index was calculated from the ratio of resting of energy expenditure to energy expenditure. Results-Fifty

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“…In order to quantitate the relative role of glucose as a substrate for neonatal cerebral oxidative metabolism, one can express the relative uptake of glucose to oxygen as a met abolic index [12], This index is:…”

Section: Arteriovenous Difference Of Glucose W ;-------------------mentioning

confidence: 99%

“…It is further possible to express the proportion of that glucose consumed by the brain which then appears as lactate in cerebral venous blood [12], This latter index was 7.51 ± 6.23% of cerebral glucose uptake (table 3). With the same method of measuring cerebral uptake of glucose, cerebral venous efflux of lactate was 0.054 ± 0.048 pmol/g/min (ta ble 3).…”

Section: Arteriovenous Difference Of Glucose W ;-------------------mentioning

confidence: 99%

Partitioning and Extraction of Glucose Regulates Cerebral Glucose Utilization in Newborn Dogs

Huang¹,

Kliegman²,

Chau³

1989

Neonatology

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We investigated the amount of fasting steady-state systemic glucose production utilized by the neonatal canine cerebral cortex. The relationship of systemic glucose production and cerebral glucose utilization were analyzed as functions of cerebral blood flow, cerebral oxygen uptake, and indirect measures of alternate fuel utilization. Fasting arterial blood glucose was 3.36 mM and glucose production was 49.6 μmol/kg/min. Average cerebral blood flow was 0.83 ml/g/min, and cerebral glucose uptake was 0.60 ± 0.15 μmol/g/min. 36.6% of systemic glucose production was utilized by the cerebral cortex. There were no correlations between systemic glucose production, cerebral blood flow, or cerebral glucose uptake with blood glucose concentration. Furthermore, total cerebral glucose uptake was static across a wide range of glucose levels. Nonetheless, the percent of glucose production used by the brain was an inverse function of systemic glucose production (r = ––0.71, p < 0.001). The cerebral extraction of glucose (27.6 ± 4.1 %) decreased as a function of increasing blood glucose levels (r = ––0.51, p < 0.05), while brain uptake index correlated with increasing systemic glucose production (r = 0.61, p < 0.02). We can conclude that the canine neonatal cerebral cortex may utilize only 37% of systemic glucose production. At low rates of glucose turnover, a larger proportion of systemic glucose production is allotted to the brain. Mechanisms that may regulate total cerebral glucose influx may be glucose permeability, or the increased extraction of glucose at lower blood glucose levels.

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Cerebral Carbohydrate Metabolism in Man During Halothane Anesthesia

Cited by 97 publications

References 0 publications

Investigating the dependence of BOLD contrast on oxidative metabolism

Investigating the dependence of BOLD contrast on oxidative metabolism

Metabolic Impact of Shivering During Therapeutic Temperature Modulation

Partitioning and Extraction of Glucose Regulates Cerebral Glucose Utilization in Newborn Dogs

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