Aluminium dialysis

De-ionized Medium-pressure boilers For renal dialysis aluminium must BS 2489 1978... 

Aluminium is the most abundant element of the lithosphere. Although a large number of persons are exposed world-wide to Al, the incidence of pulmonary effects is low (Schaller et al. 1994). In the 1970 s the effect of Al appearing in dialysis solutions on the central nervous system has become weU known. Increased Al could also be detected in several brain regions of patients with Alzheimer s disease. For the determination in biological materials the most widely used method is GF-AAS. 

In the beginning of the eighties, the clinical application of DFO expanded to a new type of patient, namely those on maintenance dialysis. As we will see in Chapter 12, some patients suffered from aluminium overload, mostly due to the use of aluminium salts as phosphate binders, while others had obvious transfusional iron overload in the pre-erythropoietin era. DFO was therefore used either to remove aluminium, excess iron or both. Nephrologists established that DFO therapy did not increase the overall incidence of bacterial infections but that it slightly increased the risk of bacteraemia caused by Y. enterocolitica or Y. pseudotuberculosis, as had been previously observed in thalassaemic patients (Boelaert et ah, 1987 Tielemans et ah,... 

Once aluminium has reached the circulation, there seems little doubt that it can cross the blood-brain barrier - the best proof being that in renal dialysis patients... 

Aluminium toxicity is the likely cause of three human disorders arising from long-term haemodialysis vitamin D-resistant osteomalacia, iron adequate microcytic anaemia, and dialysis dementia (Martin, 1994). The first of these conditions is consistent with interference with calcium deposition into bone, and the accumulation of aluminium in the bone matrix. 

Notwithstanding the excellent analytical features inherent in molecular phosphorimetric measurements, their use has been impeded by the need for cumbersome cryogenic temperature techniques. The ability to stabilize the "triplet state" at room temperature by immobilization of the phosphor on a solid support [69,70] or in a liquid solution using an "ordered medium" [71] has opened new avenues for phosphorescence studies and analytical phosphorimetry. Room-temperature phosphorescence (RTF) has so far been used for the determination of trace amounts of many organic compounds of biochemical interest [69,72]. Retention of the phosphorescent species on a solid support housed in a flow-cell is an excellent way of "anchoring" it in order to avoid radiationless deactivation. A configuration such as that shown in Fig. 2.13.4 was used to implement a sensor based on this principle in order to determine aluminium in clinical samples (dialysis fluids and concen-... 

The flow-through sensor shown in Fig. 5.17.B, developed for the determination of aluminium in real samples (dialysis fluids and concentrates), is... 

Aluminium is the third most abundant element in the earth s crust and is used widely in the manufacture of construction materials, wiring, packaging materials and cookware. The metal and its compounds are used in the paper, glass and textile industries as well as in food additives. Despite the abundance of the metal, its chemical nature effectively excludes it from normal metabolic processes. This is due largely to the low solubility of aluminium silicates, phosphates and oxides that result in the aluminium being chemically unavailable. However, it can cause toxic effects when there are raised concentrations of aluminium in water used for renal dialysis. These effects are not seen when aluminium is at the concentrations usually present in drinking water. There is currently much activity to examine the factors that influence uptake of aluminium from the diet. 

Berggren, D. (1989) Speciation of aluminium, cadmium, copper, and lead in humic soil solutions - a comparison of the ion exchange column procedure and equilibrium dialysis. Int.J. Environ. Anal. Chem., 35, 1-15. 

La Zerte, B.D., Chun, C. and Evans, D. (1988) Measurement of aqueous aluminium species comparison of dialysis and ion-exchange techniques. Environ. Sci. Technol, 22, 1106-1108. 

Visual hallucinations developed in a 56-year-old man with chronic renal insufficiency and underlying aluminium intoxication maintained on peritoneal dialysis 24 hours after he started to take clarithromycin 500 mg bd for a chest infection, and resolved completely 3 days after withdrawal (177). 

We are all exposed to aluminium from the metal utensils we use and also from the occasional use of medicinal preparations such as antacids, but it is poorly absorbed and the risk is probably very small. Dialysis patients with renal disease were found to be at risk of brain damage due to the aluminium derived from the equipment. Realization of this led to a lowering of the exposure of such patients, which decreased the occurrence of toxic effects of aluminium. Patients on dialysis with end stage renal disease, in whom some accumulation of aluminium occurred, showed evidence of metabolic abnormalities and in psychomotor function. 

An Austrian manufacturer of human albumin 20 and 25% voluntarily recalled the products because the pharmacopoeia specification for aluminium (200 ng/ml or less) for treatment of premature infants and dialysis patients cannot be guaranteed over the whole shelf life of 3 years when stored at temperatures above 8°C (21). 

Internal use in medicine can exploit the alkaline nature and adsorptive capacities of aluminium compounds (as in antacid mixtures, antidiarrheal drugs, and vaccines). Aluminium is found in medications for antacid therapy and phosphate depletion alternatives are under investigation (7). Patients on dialysis take large amounts of oral aluminium hydroxide as a means of reducing serum phosphate. Sucralfate is used to treat peptic ulceration and gastritis. 

Aluminium is toxic in patients on chronic hemodialysis and peritoneal dialysis and in those taking oral aluminium-containing medications. Aspects of aluminium safety (9) and metabolism (10) have been reviewed. The association between aluminium in drinking water and Alzheimer s disease continues to be discussed and remains controversial (11). 

Since 1976, aluminium has been known to be a cause of encephalopathy, a potentially fatal condition occurring primarily in patients on chronic dialysis (21). Difficulties in speech, disturbances of consciousness, and ataxia can be followed by psychotic episodes, personahty changes, myoclonic jerks, electroencephalographic abnormalities, convulsions, and dementia. Accumulation of aluminium can be demonstrated in the gray matter of the brain and in other tissues. If not too advanced, the condition can recede after reduction of aluminium intake and use of deferoxamine. 

When aluminium is used as a phosphate binder in patients on renal dialysis, absorption and accumulation can occur. Phosphate depletion accompanied by... 

Aluminium has a close chemical affinity with silicon, which may have a role in protecting against aluminium toxicity (94). Serum aluminium and silicon concentrations were measured in hemodialysis patients from four different centers. Although there was no relation across all centers combined, in one center there was a reciprocal relation in patients on home hemodialysis (who did not require reverse osmosis). Median (range) aluminium concentrations were higher, 2.2 (0.4-9.6) pmol/l when serum silicon was less than 150 pmol/l, and lower, 1.1 (0.2-2.8) pmol/l when serum silicon was greater than 150 pmol/l. In patients treated by hemodialysis without reverse osmosis, high serum silicon concentrations were associated with lower serum aluminium concentrations. Further work is needed to confirm a preventive role for silicon in the accumulation and subsequent toxicity of aluminium in dialysis patients. 

Sulkova S, Valek A. Aluminium elimination in patients receiving regular dialysis treatment for chronic renal failure. Trace Elem Med 1991 8(Suppl l) 26-30. 

The use of deferoxamine to reduce aluminium overload in hemodialysis patients can exacerbate aluminium encephalopathy and precipitate dialysis dementia (30-34). Confusion, disorientation, agitation, aggression, abnormal behavior, speech arrest, myoclonus, hallucinations, and seizures can occur. Some patients are very sensitive to this effect, and a test dose of deferoxamine is advisable in order to ascertain whether aluminium is excessively mobilized (35). 

In aluminium-overloaded dialysis patients, acute visual impairment can occur after only the first or second intravenous test dose of 40mg/kg deferoxamine (42-44). Visual symptoms are of retinal origin and include impairment of color vision, night bhndness, and reduced visual acuity serious and persistent visual loss can occur... 

The administration of deferoxamine to dialysis patients in order to chelate aluminium is often associated with asymptomatic hypocalcemia, which can in turn aggravate hyperparathyroidism (12). Deferoxamine-induced hypocalcemia can be corrected with supplements of vitamin D and calcium carbonate. 

Repeated monilial vaginitis was reported in patients receiving deferoxamine for dialysis-related aluminium overload (12). 

McCarthy JT, Milliner DS, Johnson WJ. Clinical experience with desferrioxamine in dialysis patients with aluminium toxicity. Q J Med 1990 74(275) 257-76. 

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