What is the Proper Composition of the Dialysate Magnesium and How Much Magnesium is Removed During Pre-Dilution Online Hemodiafiltration?

Aim: The aim of the study was to determine the ideal dialysate magnesium during hemodialysis, knowing that the solution used is not satisfactory and is often associated with low serum magnesium levels. Patients-Methods: Serum magnesium levels were initially studied in 60 hemodialyzed patients before the beginning of dialysis session with a dialysate magnesium of 1.20 mg/dl. After 6 months from the first blood samples, the dialysate magnesium was changed to 1.80 mg/dl, which continued for the following 6 months, and serum magnesium levels were determined again before the beginning of the dialysis session. In another group of 23 patients was also studied with a pre-dilution online hemodiafiltration session, with a dialysate magnesium of 1.20 mg/dl, during which serum magnesium levels were determined before the beginning of the session and 5 minutes before the end of the dialysis session, as well as the magnesium of the ultrafiltrate collected/session in a barrel. Results: Low serum magnesium levels were found in most patients with the dialysate magnesium of 1.20 mg/dl and with clinical findings in some of them, which improved significantly with an increase of dialysate magnesium to 1.80 mg/dl and reached in most of them above normal range, without showing any clinical side effect. The magnesium removed in an online hemodiafiltration session (pre-dilution) was at least equal to that ingested by a normal person in a 2-days period. Conclusion: Conventional hemodialysis with a dialysate magnesium of 1.20 mg/dl leads many hemodialyzed patients to hypomagnesemia, while the dialysate magnesium of 1.80 mg/dl is well tolerated, safe and does not cause problems for patients. Serum albumin levels affect the amount of magnesium removed during the hemodialysis session. Online HDF (pre-dilution) removes very large amounts of magnesium, capable of removing all the ingested magnesium in two days of food.