Which treatment is appropriate for mild hypovolemic hyponatremia?

Which treatment is appropriate for mild hypovolemic hyponatremia?

• A. Fluid restriction
• B. Hypertonic saline
• C. IV isotonic saline
• D. Diuretics

Answer: (C)

In hypovolemic hyponatremia, the main issue is loss of extracellular fluid volume. The body responds to this volume depletion by increasing ADH, which causes water retention and further lowers the serum sodium. The best treatment is to restore intravascular volume with intravenous isotonic saline (0.9% NaCl). This fluid expands the circulating volume, improves renal perfusion, reduces ADH release, and allows the kidneys to excrete free water, so the serum sodium rises toward normal. In mild cases, correction can occur gradually with this approach without the risks of overly rapid shifts. Fluid restriction would worsen the volume deficit and sodium would stay low. Hypertonic saline is reserved for severe, symptomatic hyponatremia (like seizures or coma) due to the risk of rapid overcorrection in milder cases. Diuretics can help with euvolemic or hypervolemic states or after initial resuscitation in some contexts, but they would worsen hypovolemia and are not first-line for mild hypovolemic hyponatremia.

In hypovolemic hyponatremia, the main issue is loss of extracellular fluid volume. The body responds to this volume depletion by increasing ADH, which causes water retention and further lowers the serum sodium. The best treatment is to restore intravascular volume with intravenous isotonic saline (0.9% NaCl). This fluid expands the circulating volume, improves renal perfusion, reduces ADH release, and allows the kidneys to excrete free water, so the serum sodium rises toward normal. In mild cases, correction can occur gradually with this approach without the risks of overly rapid shifts.

Fluid restriction would worsen the volume deficit and sodium would stay low. Hypertonic saline is reserved for severe, symptomatic hyponatremia (like seizures or coma) due to the risk of rapid overcorrection in milder cases. Diuretics can help with euvolemic or hypervolemic states or after initial resuscitation in some contexts, but they would worsen hypovolemia and are not first-line for mild hypovolemic hyponatremia.