Exogenous Toxins

In the early 1970s a serious encephalopathic syndrome was described in patients receiving hemodialysis. It consisted of stuttering speech or mutism, myclonic 

Furthermore, certain factors may increase intestinal aluminum absorption. We have previously described severe hyperaluminemia resulting in an acute rapidly fatal encephalopathy in four uremic patients who had been taking aluminum hydroxide and Shohl s solution, an alkalinizing buffer of sodium citrate and citric acid. The encephalopathy resembled the earlier dialysis dementia of the 1970s, but was much more acute, culminating in death within 3 weeks (B4, B5). 

Copper used in the wiring of dialysis systems may be leached in an acidic medium. It then diffuses into the blood, causing hemolysis. Symptoms consist of flushing, chills, nausea, vomiting, abdominal cramps, and diarrhea. This problem can be avoided by deionization of the dialysis water. The deionizer should be checked periodically to assure it is not being exhausted (M23). 

Zinc may also be leached from new galvanized iron piping. The plasma and red blood cells take up zinc even when its concentration in the dialysate is only one-third that of the plasma, and this may cause a severe hemolytic anemia. Deionization of the dialysis water should prevent this problem (P10). 

The use of reverse osmosis to treat dialysis water does not remove chloramine, but the addition of ascorbic acid does. Treating the dialysis water with activated charcoal effectively removes chloramine, but periodic water testing with o-tol-idine should nevertheless be undertaken. This reagent detects total chloride, i.e., OC1, HOC1, NHC12, and NC13. Interestingly, chloramine contamination of natural waters has also caused hemolysis in several species of freshwater fish (El). 

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Acute tubular necrosis Ischemic Hypotension Vasoconstriction Exogenous toxins Contrast dye Heavy metals Drugs (amphotericin B, aminoglycosides, etc.) (continued)... 

Acute tubular necrosis (exogenous toxins) Aminoglycosides, amphotericin, cisplatin, radiocontrast agents, methoxyflurane, outdated tetracyclines, cephalosporins, mithramycin, calcineurin inhibitors, pentamidine, IVIG, ifosfamide, zoledronate, cidofovir, adefovir, tenofovir FENa>2%, UOsm <350, urinary sediment contains granular casts, renal epithelial cells... 

The metabolic changes observed in uremia result from the decline in renal excretory function, hence the retention of a legion of substances the loss of vital renal hormones (e.g., erythropoietin) and enzymes (e.g., la-hydroxylase) the effect of the uremic environment on organ function, intermediary metabolism, and transport processes dialysis-related problems and exogenous toxins. 

As patients live longer with dialysis treatment, they begin to develop yet another set of problems related to dialysis itself, and to the chronic accumulation of endogenous compounds (p2-microglobulin) and exogenous toxins (aluminum). P2-Microglobulin causes dialysis amyloidosis with the carpal tunnel syndrome and destructive arthropathy. Aluminum causes anemia, osteomalacia or adynamic bone disease, and encephalopathy. 

Clearance tests of liver function assess a number of physiologic activities including hepatic uptake, hepatic metabolism, and hepatic excretion. Typical clearance tests of liver function include indocyanine green (ICG), antipyrine clearance test and C aminopyrine breath test. These tests give an estimation of the ability of the liver to extract and detoxify exogenous toxins (xenobiotics). Measuring the excretion of endogenously produced serum bile acids is an additional measure of hepatic clearance and has been used as a sensitive measure of early solvent hepatotoxicity." "... 

Infection, trauma, exogenous toxins 4 Cerebral oxygen level... 

Cellular metabolism, exogenous toxin, endogenous toxin... 

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