• Management of acute or chronic hyponatremia (Na < 135 mEq/L).
• Symptomatic hyponatremia (seizures, altered mental status, coma).
• Calculating the impact of various IV fluids on serum sodium levels.
• Monitoring the safety of sodium correction to avoid over-correction.

Previously known as Central Pontine Myelinolysis. Rapid correction of chronic hyponatremia causes water to exit brain cells too quickly, leading to irreversible demyelination of the pons and other brain structures.

• The formula does NOT account for urinary losses, which can cause Na to rise much faster than predicted (especially as ADH levels drop).
• In volume-depleted patients, once fluids are replaced, ADH secretion shuts off, leading to a "water diuresis" that can dangerously accelerate Na correction.
• Always use "Corrected Sodium" if the patient is significantly hyperglycemic.

• Determine chronicity: If > 48h or unknown, treat as chronic.
• For severe symptoms: Give 100 mL bolus of 3% saline; repeat up to 3x if symptoms persist.
• Frequent Monitoring: Check Serum Na every 2–4 hours during active correction.
• The "Desmopressin Clamp": In patients at very high risk for over-correction, some clinicians use DDAVP to prevent water diuresis and lock the Na rise at a predictable rate.
• If over-correction occurs: Consider giving D5W or DDAVP to lower the sodium back toward the target limit.

Nicolaos Madias and Horacio Adrogué revolutionized electrolyte management by providing a simplified bedside equation. Before this, clinicians relied on complex "sodium deficit" equations that often failed to account for the impact of volume in the infusate.