Free Water Deficit in Hypernatremia
Calculates free water deficit by estimated total body water in a patient with hypernatremia or dehydration.
Advice
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Hypernatremia is an elevation in serum sodium, indicating a free water deficit or dehydration.
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In addition to calculating the free water deficit, the cause should be determined (e.g., loss of free water in the urine or stool, or lack of access to sufficient free water).
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Patients may simultaneously be volume depleted and dehydrated.
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If this is suspected, correct the volume deficit with isotonic fluids first before correcting the water deficit calculated here.
Management
Sufficient free water should be provided either orally or intravenously (using a solution such as 5% dextrose) to correct the serum sodium by up to 10 mEq/L in the first 24 hours.