Can hypermagnesemia occur in PN patients with normal liver function?

• A. It cannot occur
• B. Yes, hypermagnesemia can occur in all patients on long-term PN regardless of liver function
• C. Only in short-term PN
• D. No, only with liver dysfunction

Answer: (B)

Magnesium balance in parenteral nutrition depends mainly on how much magnesium is delivered and how well the kidneys excrete the excess. The liver doesn’t regulate magnesium clearance in the same way, so having normal liver function does not protect against magnesium accumulation. In long-term PN, magnesium is infused continuously, and if the dose is high or renal excretion is impaired, magnesium can build up even with normal liver function. That’s why monitoring magnesium levels and adjusting the PN formulation is essential for all patients on long-term PN, regardless of liver status.