Risk of aluminium intoxication in long-term acetate Redy dialysis

Closed-circuit dialysis using the Redy sorbent cartridge to regenerate the dialysate has been incriminated in previous reports as a cause of severe fracturing osteomalacia and fatal encephalopathy in several patients treated with this procedure for 15-36 months. In a retrospective study, we compared 15 unselected patients who had received Redy dialysis for 66 +/- 14 months with 15 control patients dialysed with single passage of dialysate. Redy and control patients were matched for age, sex, and duration of dialysis. They belonged to two dialysis centres, situated in the same geographical area and having a common water supply. Mean serum and bone aluminium concentrations were slightly greater in the Redy group but the differences were not significant. Pathological fractures had occurred in two Redy patients and in one control, but could not be attributed to aluminium-induced bone disease. Although the histochemical staining for aluminium in bone was positive in six patients, diagnosis of aluminium-induced bone disease was made in one case only. The results of bone histomorphometry did not differ significantly between the two groups. Our findings may be explained by the strict application of the measures required to avoid aluminium contamination of the Redy dialysate, i.e. sufficient rinsing before dialysis, use of almost aluminium-free water, and of acetate-buffered dialysate.