Loss of zinc and selenium does not occur through peritoneal dialysis

A prospective study was done to determine whether zinc (Zn) and selenium (Se) loss occurs in patients on continuous ambulatory peritoneal dialysis through their dialysate effluent. Fifty pairs of aliquots of dialysis fluid were collected from 29 patients. Each paired set of specimens consisted of the dialysate fluid before instillation into the peritoneal cavity and a specimen of the spent effluent after dialysis for comparison. Zn and Se concentrations were measured using inductively coupled plasma atomic emission spectrophotometry. The range of dialysate fluid Zn concentration before instillation was 0 to 1.75 microg/mL and that for Se was 0 to 0.33 microg/mL. Ranges for Zn and Se in the postdialysis effluent were 0 to 0.60 and 0 to 0.56 microg/mL, respectively. The concentration differences in 50 pairs of samples were analyzed with Wilcoxon's test. The difference in Zn levels between the predialysis specimen and the effluent was 0.009 +/- 0.036 microg/mL (P = 0.154). The difference for Se was 0.018 +/- 0.21 microg/mL (P = 0.118). In conclusion, no significant loss or gain of Zn or Se occurs in patients undergoing continuous ambulatory peritoneal dialysis.