Hypomagnesemia in Continuous Ambulatory Peritoneal Dialysis Patients Dialyzed with a Low-Magnesium Peritoneal Dialysis Solution

Objective Previous studies have shown a decrease in serum magnesium (Mg) concentration when continuous ambulatory peritoneal dialysis (CAPD) patients previously maintained on a 1.0 –1.2 mEq/L Mg peritoneal dialysis solution (PDS) were dialyzed with a 0.5 mEq/L Mg PDS. However, the prevalence of hypomagnesemia in CAPD patients dialyzed with low-Mg PDS is unknown. Design A retrospective study to determine the prevalence of hypomagnesemia and the factors associated with its occurrence in CAPD patients dialyzed using a 0.5 mEq/L Mg PDS. Setting A CAPD unit in a large Veterans Affairs Hospital. Patients All our CAPD patients (33) enrolled over a 52month period. Results All patients had serum magnesium levels higher than 1.25 mEq/L prior to use of low-Mg PDS. Hypomagnesemia (serum Mg < 1.25 mEq/L) developed in 21/33 patients (64%) when a 0.5 mEq/L Mg PDS was employed. Hypomagnesemia developed a mean of 8.2 months after beginning treatments. The duration of dialysis and the number of episodes of peritonitis did not differ between patients with and those without hypomagnesemia. Serum albumin levels were significantly lower in patients with hypomagnesemia (2.5±0.12 g/dL vs 3.2±0.12, p < 0.01). Magnesium supplements were given to 13 patients; following this therapy, serum magnesium values became normal. Conclusions CAPD patients dialyzed with a 0.5 mEq/L Mg PDS may develop a considerable fall in serum magnesium level and may require magnesium supplements in order to restore normal serum values.