From the Research
To approach hypernatremia, first identify and address the underlying cause while simultaneously correcting the sodium imbalance, as this is crucial for preventing morbidity and mortality, and improving quality of life. When managing hypernatremia, it is essential to assess the patient's volume status, which can be hypovolemic, euvolemic, or hypervolemic, as this guides the treatment approach 1. The following steps are recommended:
- For hypovolemic hypernatremia, administer isotonic fluids (0.9% saline) initially to restore hemodynamic stability, then switch to hypotonic fluids (0.45% saline or 5% dextrose in water) 2.
- For euvolemic hypernatremia, provide free water replacement through oral intake if possible or 5% dextrose in water intravenously 3.
- For hypervolemic hypernatremia, combine water replacement with loop diuretics like furosemide 20-40mg IV to promote sodium excretion 4. It is also crucial to calculate the free water deficit using the formula: Free water deficit = 0.6 × weight (kg) × [(measured Na⁺/140) - 1], and correct sodium levels gradually, aiming for a decrease of no more than 10 mEq/L in 24 hours to prevent cerebral edema 5. Monitoring serum sodium every 2-4 hours during correction is also vital, as hypernatremia occurs when serum sodium exceeds 145 mEq/L, typically due to water loss exceeding sodium loss or from excessive sodium intake, and rapid correction can cause cerebral edema as brain cells rapidly take up water, leading to neurological complications 1.