Comparison of serum calcium fractions during haemodialysis and peritoneal dialysis

mined in anaerobic serum from healthy volunteers. patients immediately before and after haemodialysis and patients on continuous ambulatory peritoneal dialysis (CAPO). Protein-bound. complexed and albumin-corrected total calcium concen-trations were calculated from the results. During haernodialysis, complexed calcium did not change, whereas the other fractions increased. For patients on CAPO, the total, ionised and protein-bound calcium results were frequently lower than the reference group, whereas the ultrafiltrable and albumin-corrected total calcium results were within or higher than the reference group. Albumin-corrected total calcium for all subjects correlated better with ultrafiltrable calcium than with ionised calcium. It was concluded that low ionised calcium concentrations found in CAPO patients may be related to low albumin concentrations, and the concentra-tion of physiologically active calcium may be normal in these patients. One aim of dialysis treatment in chronic renal failure is to maintain normal serum calcium levels, thereby preventing secondary hyper