Prevention of aluminium exposure through dialysis fluids. Analysis of changes in the last 8 years.

Despite extensive measures to control aluminium exposure, chronic and acute episodes of aluminium intoxication still occur. The objective of this study was to analyse the changes in the aluminium content of dialysis fluid and the effect on serum aluminium in different dialysis centres in Spain in the last 8 years. For this purpose, the aluminium content in dialysis fluid and serum samples (N=5609) from 17 dialysis centres was analysed for >8 years (from the last quarter of 1988 to 1996). In that period of time, the percentage of dialysis fluid samples with acceptable concentrations of aluminium (<2 microg/l) increased from 0% in 1988 to 80% in 1996. The percentage of dialysis fluid samples with high aluminium levels (>6 microg/l) ranged between 37.5% in 1988 and 2.3% in 1996. The improvement in the quality of the dialysis fluid resulted in lower values of serum aluminium. The percentage of serum samples with low aluminium (<20 microg/l) increased from 16.5% in 1988 to 54.2% in 1966. The mean serum aluminium correlated with the mean dialysis fluid aluminium (r=0.55, P<0.001). A higher correlation was found when the aluminium in dialysis fluid ranged between 4 and 10 microg/l (r=0.802, P<0.001), and no correlation was found when the aluminium in dialysis fluid was <4 microg/l. Even taking into account that the dialysis fluid is not the only source of aluminium for dialysis patients, our study clearly demonstrated a close relationship with the serum aluminium content. Therefore, we must emphasize the necessity for controlling the aluminium content in dialysis fluid more often than is done at present.