Magnesium Replacement in Renal Failure

Critical Distinction: Renal Failure Without vs. With Dialysis

The European Society for Clinical Nutrition and Metabolism (ESPEN) guidelines recommend using dialysis solutions containing magnesium rather than intravenous supplementation to maintain serum magnesium levels in patients on kidney replacement therapy (KRT) 1, 2, 3, 4
Maintain serum magnesium ≥0.70 mmol/L (approximately 1.7 mg/dL) in patients on KRT 1
Intravenous supplementation of electrolytes in patients undergoing continuous kidney replacement therapy (CKRT) is NOT recommended 1, 3
Use commercial KRT solutions enriched with magnesium, which can be safely used as dialysis and replacement fluids to prevent hypomagnesemia 1, 2, 3
Exogenous supplementation carries severe clinical implications and risks, and prevention through modulating KRT fluid composition is the most appropriate therapeutic strategy 1, 3
Hypomagnesemia occurs in 60-65% of critically ill patients on CKRT, particularly with regional citrate anticoagulation where citrate chelates ionized magnesium 2, 4
Regional citrate anticoagulation dramatically increases magnesium losses through chelation and removal as magnesium-citrate complexes 2, 4
Assess dialysis status and check current dialysate composition to determine the need for magnesium supplementation or adjustment of dialysate magnesium concentration 1, 3

The target serum magnesium concentration should be ≥0.70 mmol/L, according to the Clinical Nutrition guidelines 5, 6

For hypophosphatemia in acutely ill patients, the preferred approach is to use dialysis solutions containing phosphate rather than exogenous supplementation, as recommended by Clinical Nutrition 5, 7
The target serum phosphate levels should be >0.81 mmol/L, according to Clinical Nutrition guidelines 6
Monitor serum phosphate levels daily, as suggested by Clinical Nutrition 5

In patients on continuous kidney replacement therapy (CKRT), consider using dialysis solutions enriched with magnesium and phosphate, as recommended by Clinical Nutrition 5, 6, 7
Patients receiving regional citrate anticoagulation during CKRT are at higher risk of hypomagnesemia due to magnesium-citrate complex formation, according to Clinical Nutrition 6