The retention of one-half of the administered water will lead to a further reduction in the serum sodium concentration even though the serum sodium concentration may initially rise because the isotonic saline is hypertonic to the patient.

Does half normal saline cause hyponatremia?

In this sample of 233 acutely ill medical and surgical patients, 0.45% normal saline induced hyponatremia in 15% of the patients, and none of the fluids induced significant changes in acid–base balance.

Why would you use half normal saline?

Half Normal Saline

The difference is that half normal saline contains half the chloride concentration of normal saline. It's designed to treat patients suffering from cellular dehydration and can be used for things like: Raising your overall fluid volume. Water replacement.