Tissue oxygenation

The primary cause of anemia in patients with CKD is a decrease in EPO production. With normal kidney function, as Hgb, hematocrit (Hct), and tissue oxygenation decrease, the... 

Provide supportive measures that counter physiologic abnormalities such as hypoxemia, hypotension, and impaired tissue oxygenation. 

Terminal activity causes an increase in local cerebral blood flow that can be quantified by measuring the accompanying increase in tissue oxygen. Alkaline pH changes... 

E.M.R. Doppenberg, A. Zauner, R. Bullock, J.D. Ward, P.P. Fatouros, and H.F. Young, Correlations between brain tissue oxygen tension, carbon dioxide tension, pH, and cerebral blood flow - a better way of monitoring the severely injured brain Surg. Neurol. 49, 650-654 (1998). 

After successful resuscitation, the primary goals include optimizing tissue oxygenation, identifying precipitating cause(s) of arrest, and preventing... 

Blood lactate concentrations may be used as another measure of tissue oxygenation and may show better correlation with outcome than 02 transport parameters in some patients. 

Maintenance of adequate tissue oxygenation is important in the treatment of sepsis and is dependent on adequate perfusion and adequate oxygenation of the blood. 

Physiological action Interferes with body tissues, oxygen use and rate of breathing... 

M. Cope. The development of a near-infrared spectroscopy system and its application for noninvasive monitoring of cerebral blood and tissue oxygenation in the newborn infant. PhD thesis, University College London, London, 1991. 

M. Cope and D.T. Delpy. System for long-term measurement of cerebral blood flow and tissue oxygenation on newborn infants by infra-red transillumination. Medical and Biological Engineering and Computing, 28 289-294, 1988. 

The key to unraveling the toxicity of fluoracetate came from observations of Buffa and Peters (1949) that in animals treated with FAc, considerable quantities of citrate accumulated in some tissues. Oxygen uptake was also diminished. The citric acid cycle was thus implicated as the site of inhibition. Fluorcitrate was then isolated from the affected tissues. It was found to be a powerful competitive inhibitor of aconitase, thus blocking citrate oxidation. The suggestion was therefore made that fluoracetate was toxic not in itself, but because it was metabolized in cells via fluoracetyl CoA to give a toxic derivative, an example of lethal synthesis —the capacity of organisms to metabolize nontoxic compounds and convert them to potentially lethal products. 

The in situ generation of 2,3 BPG is accelerated by low atmospheric Po2, for example at high altitude. Lower Po2 at altitude could compromise tissue oxygenation so to avoid cellular hypoxia, 02 is released from haemoglobin. 

Manley GT, Hemphill JC, Morabito D, et al. Small-volume resuscitation with the hemoglobin substitute HBOC-201 effect on brain tissue oxygenation. Adv Exp Med Biol 2003 530 311. 

Pearce LB, Gawryl MS. The pharmacology of tissue oxygenation by biopure s hemoglobin-based oxygen carrier, Hemopure (HBOC-201). Adv Exp Med Biol 2003 530 261. 

Nitrites may be used as an antidote for cyanide poisoning if given rapidly. They convert hemoglobin to methemoglobin, which binds cyanide in the blood before reaching the tissues. Oxygen is also given if possible. 

On the other hand, hyperoxic conditions (excess tissue oxygen levels) promote a decrease in EPO production. 

Patients are initially grouped by independent measurements of red cell mass and plasma volume. Where the latter is contracted the increase in packed red cell volume or haemoglobin in the peripheral blood is spurious or relative. In true erythrocytosis the red cell mass, and often the plasma volume, are both expanded. These individuals are further subdivided, depending upon whether tissue oxygenation is impaired, with consequent activation of normal physiological mechanisms. Conversely, this situation may reflect pathological production of erythropoietin or uncontrolled overgrowth of red cells in the chronic myeloproliferative syndrome. 

B.J. Dardzinski, C.H. Sotak, Rapid tissue oxygen tension mapping using F inversion-recovery echo-planar imaging of Perfluoro-15-crown-5-ether, Magn. Reson. Med. 32 (1994) 88-97. 

R.P. Mason, H.P. Shukla, P.P. Antich, Oxygent A novel probe of tissue oxygen tension. Biomater. Artif. Cells Immobilization. Biotechnol. 20 (1992) 929-935. 

R.P. Mason, R.L. Nunnally, P.P. Antich, Tissue oxygenation A novel determination using F surface coil spectroscopy of sequestered perfluorocarbon emulsion, Magn. Reson. Med. 18 (1991) 71-79. 

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