For severe hyponatremia with neurologic symptoms, what is the recommended initial treatment?

• A. Desmopressin
• B. Hypertonic saline 3% administration with careful correction and monitoring
• C. 0.9% saline
• D. Water restriction

Answer: (B)

When severe hyponatremia presents with neurologic symptoms, the brain is storing excess water and swelling is driving the symptoms, so the priority is to rapidly raise the serum sodium safely. The best initial treatment is hypertonic saline (3% NaCl) given in controlled boluses to quickly improve neurologic status by about 4–6 mEq/L in the first few hours. Use small, repeatable doses (for example 100 mL of 3% saline over 10 minutes, repeated if needed) and monitor sodium levels every 2–4 hours to avoid overcorrecting, which can cause osmotic demyelination. After stabilization, slow the correction and address the underlying cause.

Desmopressin isn’t used to treat acute symptomatic hyponatremia as the first step. Normal saline may not correct sodium quickly enough and can be unsafe depending on the patient’s volume status. Water restriction helps chronic, less urgent hyponatremia, not an emergency with neurologic symptoms.