Acid-base status, effect

Victery W, Vander AJ, Mouw DR. 1979. Effect of acid-base status on renal excretion and accumulation of lead in dogs and rats. Am J Physiol 6 F398-F407. 

The importance of these secondary effects on acid-base status, metal concentration, and toxicity are still being studied. The recovery from acidification has been simulated by MAGIC for many watersheds, but sufficient time has not elapsed since acid inputs declined to assess the accuracy of the model predictions (Majer et aL, in review). 

In patients with colic, the most relevant clinical sign of hypokalemia is reduced intestinal motility (Geimari 1998, Schaer 1999). However, the association between h) okalemia and ileus in the horse remains undetermined. Other clinical signs include muscle weakness, lethargy and inability to concentrate urine (Schaer 1999). Cardiac conduction abnormalities are rare except in severe hypokalemia and in pre-existing cardiac dysfunction (Gennari 1998). The effect of potassium on acid-base status is small and need not be considered clinically (Corley Marr 1998). 

Acid-base status Cannot by itself explain seizure protective effect Nonnal serum pH in patients on KD suggests that metabolic acidosis is compensated Brain pH is normal... 

Whereas simple buffers rapidly become ineffective as the association of the hydrogen ion and the anion of the weak acid reaches equilibritim. the bictubonate system keeps working because the carbonic acid is removed as carbon dioxide. The 1 i mi I to the effect i veness of the bicarbonate system is the initial concentration of bicarbonate. Only when all the bicarbonate is used up does the system have no further buffering capacity. The acid-base status of patients is assessed by consideration of the bicarbonate system of plasma. 

The depletion by membrane permeation of C02 in blood introduces cause for concern. This affects the evaluation of PBot and also shifts the position of the 02 dissociation curve. The correction for this effect requires the continuous evaluation of the acid—base status of the blood sample. Using an initial reference point obtained from a separate pH measurement and Pco2> the variation in pH during the withdrawal process can be determined with incremental measurements of PBc02 ( ) ... 

Ngan Kee WD, Lee A, Khaw KS, Ng FF, Karmakar MK, Gin T. A randomized double-blinded comparison of phenylephrine and ephedrine infusion combinations to maintain blood pressure during spinal anesthesia for cesarean delivery the effects on fetal acid-base status and hemodynamic control. Anesth Analg 2008 107(4) 1295-302. 

Ture H, Mercan A, Koner O, Aykac B, Jure U. The effects of propofol infusion on hepatic and pancreatic function and acid-base status in children undergoing craniotomy and receiving phenytoin. Anesth Analg 2009 109(2) 366-71. 

The renal compensation is now the opposite, with the kidney losing bicarbonate. As with the original compensation, it takes a few days for renal mechanisms to have their effects in full and for normal blood biochemistry to be restored. During this time, the acid base status gradually moves along the line from point C to point N in Figure 3.3. 

Explain that the acid-base status can be deduced from the blood biochemistry in cases of uncompensated respiratory or metabolic disorder. Demonstrate examples of compensated disorders (e.g. compensated respiratory acidosis and compensated metabolic alkalosis) in which the same abnormality of blood biochemistry may be reached by different routes. Hence explain the need, in such cases, to seek each cause and evaluate its effect. 

Further reading Duhm, J. (1972). The effect of 2,3-DPG and other organic phosphates on the Donnan equilibrium and the oxygen affinity of human blood. In Rorth, M. and Astrup, P. (eds.) Oxygen Affinity of Haemoglobin and Red Cell Acid Base Status. (Alfred Benzon Symposium, IV). p. 583. (New York Academic Press)... 

The development of these ion-molecule equilibrium measurements has completely changed the status of acid/base reactions (and of other reactions cf. Sechon 5.2) in the gas phase. It is now possible to compare the complex and poorly understood situahon in solution with the simple state in the gas phase. It is also possible to determine the acidity of all acids in the gas phase, from the weakest such as methane to the strongest. In solution, however, due to the levelling effect of the solvent or solubility problems, only a certain range of acids can be measured in a given solvent. 

Antioxidant-Treated Beef Patties. The effect of several primary antioxidants, PG, TBHQ, Tenox 20 (which contains TBHQ and citric acid) and Tenox 4A (which contains BHA and BHT) were also evaluated by instrumental, chemical and sensory methods for their effectiveness in raw/stored and cooked/stored beef, see Tables 1-4. These particular antioxidants were chosen based on their antioxidant effects on MFD as determined previously (14) and because of their GRAS status. Experimental samples were prepared similarly to those of the 0-and 2-day controls, except the antioxidants, either dissolved or suspended in water, were mixed into the raw ground meat. 

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