Cerebral salt wasting syndrome is characterized by which triad?

Cerebral salt wasting syndrome is characterized by which triad?

• A. Hyponatremia, volume contraction, high urine sodium
• B. Hypernatremia, volume expansion, low urine sodium
• C. Hyponatremia, volume expansion, low urine sodium
• D. Hyperkalemia, dehydration, high urine potassium

Answer: (A)

Cerebral salt wasting happens when the brain injury triggers ongoing renal loss of sodium, which pulls water along and creates a state of hyponatremia with actual extracellular fluid volume depletion. The kidneys keep dumping sodium, so the urine sodium concentration remains high despite low serum sodium. That combination—hyponatremia, volume contraction, and high urine sodium—is the defining triad. So the best choice is the one that lists low serum sodium, signs of volume depletion, and high urine sodium. The other options don’t fit because they describe hypernatremia or volume expansion or low urine sodium, which are inconsistent with cerebral salt wasting.

Cerebral salt wasting happens when the brain injury triggers ongoing renal loss of sodium, which pulls water along and creates a state of hyponatremia with actual extracellular fluid volume depletion. The kidneys keep dumping sodium, so the urine sodium concentration remains high despite low serum sodium. That combination—hyponatremia, volume contraction, and high urine sodium—is the defining triad.

So the best choice is the one that lists low serum sodium, signs of volume depletion, and high urine sodium. The other options don’t fit because they describe hypernatremia or volume expansion or low urine sodium, which are inconsistent with cerebral salt wasting.