Episode 967: Dilutional Hyponatremia

Contributor: Taylor Lynch, MD

Educational Pearls:

Dilutional Hyponatremia:

Occurs when there is an excess of free water relative to sodium in the body. Causes a falsely low sodium concentration without a true change in total body sodium.

Commonly seen in DKA:

Hyperglycemia raises plasma osmolality. Water shifts from the intracellular to extracellular space. This dilutes serum sodium, creating apparent hyponatremia.

Corrected sodium calculation:

Use tools like MDCALC, or apply this formula:

Add 1.6 mEq/L to the measured sodium for every 100 mg/dL increase in glucose above 100.

Clinical...