0000000000017141
AUTHOR
R. Schubert
Regional cerebral blood flow and regional metabolism in cold induced oedema.
24 hours following a cold induced oedema in cats rCBF was measured in the lesion area, the bluish stained cortex immediately adjacent to the lesion, a cortical area remote from the lesion, and in the contralateral uninjured hemisphere. Thereafter the brain was frozen and the respective tissue areas were removed and analyzed for water and electrolyte content as well as metabolite concentrations. It seems, that in the neighbourhood of a local lesion at least 3 different brain regions can be differentiated with regard to their characteristic pattern of data. In non-oedematous regions either hyperaemia or hypoaemia could be observed. In areas with local brain oedema rCBF was reduced inversely p…
Nomogramme zur Bestimmung des intraerythrocytären Säure-Basen-Haushlts
Auf Grundlage der Berechnungen von Brodda u. v. Mengden (1971) werden zwei Nomogramme vorgelegt, die die Zusammenhange der wichtigsten Saure-Basen-Parameter im Erythrocyten und deren Abhangigkeit von der O2-Sattigung wiedergeben. Nach Messung des WertetripelsP CO 2,P O 2 und pH im Blut lassen sich mit Hilfe dieser Nomogramme aktueller und Standard-Basenuberschus, aktuelles und Standard-Bicarbonat, Pufferbasen und Standard-pH im Erythrocyten ermitteln. Die zugeordneten Werte fur das Vollblut erhalt man zusatzlich bei Benutzung des zweiten Nomogramms. Vorteil dieser Nomogramme ist die rasche Erfassung des gesamten intraerythrocytaren Saure-Basen-Haushaltes, ohne das Aquilibrierung mit Gasgemi…
The course of intracranial pressure and volume-pressure relationships following extirpation of meningiomas and astrocytomas
Thirty-five patients with meningiomas were compared with 37 patients with astrocytomas with respect to the postoperative course of their ICP and elastance. In the case of the meningioma patients, the ICP increased on average over a longer period and achieved higher values than in the astrocytoma patients. In the first group, the elastance attained values that were three times as high as in the second group. There was no fixed relationship between pressure and elastance in the two groups of patients.
TISSUE OXYGENATION AND TISSUE METABOLISM IN THE BRAIN CORTEX DURING PRONOUNCED ARTERIAL HYPOCAPNIA
Publisher Summary This chapter describes the tissue oxygenation and tissue metabolism in the brain cortex during pronounced arterial hypocapnia. Acute arterial hypocapnia induced by hyperventilation leads to typical reactions in the circulation and the metabolism of the brain tissue. With a lowering of arterial CO2 tension, the cerebro-vascular resistance (CVR) increases resulting in a decrease of cerebral blood flow. The changes in CVR are a consequence of decreasing hydrogen ion and potassium ion concentrations in the perivascular space of the brain arterioles. The corresponding changes in the brain metabolism are characterized by elevated concentrations of lactate and pyruvate and an inc…
Cerebral Oxygen Supply in Brain Edema and During Ventriculo-Cisternal Perfusion
Numerous brain injuries and brain tumors lead to edema in brain tissue which can have consequences for the oxygen supply to the damaged tissue as well as to adjacent tissue areas. In studies made of the blood flow and oxygen supply in perifocal edematous tissue of brain tumors and lesions in patients undergoing various brain operations a direct relationship between the regional blood flow and the water content could be demonstrated (3). As the water content of the tissue increased, the blood flow through it diminished. In many cases, the reduction of the blood flow in the brain tissue induced an insufficient oxygen supply. In the tissue samples under investigation, the CrP and ATP concentra…
Tissue Oxygenation in Normal and Edematous Brain Cortex During Arterial Hypocapnia
Since arterial hypocapnia causes a cerebral blood flow decrease, hypocapnic conditions are induced in patients with severe traumatic brain injury by controlled hyperventilation in order to reduce the intracranial pressure (Gordon, 1971). Beneficial effects on the clinical course of patients, however, can be observed only under conditions of moderate hypocapnia. As shown by animal experiments severe arterial hypocapnia results in insufficient oxygen supply conditions in brain tissue (Grote et al., 1981), which subsequently influences the brain metabolism (Granholm et al., 1969, 1971) and counteracts the influence of hypocapnia on cerebral blood flow regulation (Grote et al., 1981). The prese…
The Significance of Low O2-Tensi0ns in the Brain Cortex for Occurrence of Metabolic Alterations under Critical Flow Conditions
A reduction in the 02 supply to the brain cortex leads to O2 deficiency and curtailment of neuronal metabolism and function as soon as a minimal cellular O2 tension of 0.1 – 1 mmHG (13 – 133 Pa) can no longer be maintained (Chance et al., 1964; Grote 1967). The hypoxia-induced metabolic alterations are characterized by decreased tissue levels of the energy-rich phosphate compounds PCr and ATP. In addition, elevated concentrations of lactate, pyruvate and NADH and an increase in the lactate/pyruvate ratio and in the NADH/NAD+ ratio are to be expected (Duffy et al., 1972; Granholm and Siesjo 1969; Granholm et al., 1969; Granholm and Siesjo 1971; Grote 1978; Grote and Schubert 1982; Norberg an…