Hypertonic saline is indicated for severe hyponatremia when serum sodium falls below what threshold?

Hypertonic saline is indicated for severe hyponatremia when serum sodium falls below what threshold?

• A. <140 mEq/L
• B. <130 mEq/L
• C. <120 mEq/L
• D. <125 mEq/L

Answer: (C)

The main idea here is when to use hypertonic saline in hyponatremia. Hypertonic saline is reserved for severe hyponatremia because these patients are at risk of brain swelling and life-threatening symptoms; a prompt but controlled rise in serum sodium can alleviate cerebral edema. The threshold for this intervention is when the serum sodium falls below 120 mEq/L. At or below this level, the brain is more vulnerable, and a small, rapid increase in sodium with 3% saline can rapidly reduce intracranial pressure and neurologic risk. In less severe hyponatremia (above 120 mEq/L) or without severe symptoms, management is gentler—often fluid restriction or isotonic saline—as the risks of overcorrecting sodium are significant. When using hypertonic saline, the goal is a careful rise of about 4-6 mEq/L in the first several hours, then cautious continuation with close monitoring to avoid overcorrection and osmotic demyelination.

The main idea here is when to use hypertonic saline in hyponatremia. Hypertonic saline is reserved for severe hyponatremia because these patients are at risk of brain swelling and life-threatening symptoms; a prompt but controlled rise in serum sodium can alleviate cerebral edema. The threshold for this intervention is when the serum sodium falls below 120 mEq/L. At or below this level, the brain is more vulnerable, and a small, rapid increase in sodium with 3% saline can rapidly reduce intracranial pressure and neurologic risk. In less severe hyponatremia (above 120 mEq/L) or without severe symptoms, management is gentler—often fluid restriction or isotonic saline—as the risks of overcorrecting sodium are significant. When using hypertonic saline, the goal is a careful rise of about 4-6 mEq/L in the first several hours, then cautious continuation with close monitoring to avoid overcorrection and osmotic demyelination.