In hyponatremia management when the patient is hypovolemic, which fluid is typically used for resuscitation?

In hyponatremia management when the patient is hypovolemic, which fluid is typically used for resuscitation?

• A. Hypertonic saline
• B. Normal saline
• C. D5W
• D. LR

Answer: (B)

When hyponatremia occurs with low circulating volume, the priority is to restore intravascular volume with an isotonic fluid. Normal saline provides sodium and chloride in a concentration close to plasma, so it expands the circulating volume and helps raise the serum sodium gradually without causing a dangerous shift. Hypertonic saline is reserved for severe, life-threatening neurologic symptoms and is not the initial choice for simple hypovolemic hyponatremia. D5W adds free water after metabolism, which would further dilute the sodium and worsen hyponatremia. Lactated Ringer’s has less sodium than normal saline and contains lactate, making it a less ideal primary choice for correcting hyponatremia in this setting. So, the best initial resuscitation fluid is normal saline.

When hyponatremia occurs with low circulating volume, the priority is to restore intravascular volume with an isotonic fluid. Normal saline provides sodium and chloride in a concentration close to plasma, so it expands the circulating volume and helps raise the serum sodium gradually without causing a dangerous shift. Hypertonic saline is reserved for severe, life-threatening neurologic symptoms and is not the initial choice for simple hypovolemic hyponatremia. D5W adds free water after metabolism, which would further dilute the sodium and worsen hyponatremia. Lactated Ringer’s has less sodium than normal saline and contains lactate, making it a less ideal primary choice for correcting hyponatremia in this setting. So, the best initial resuscitation fluid is normal saline.