Can Dextrose 5% (five percent dextrose) 0.45 NaCl (sodium chloride) be used for hypernatremia and volume expansion?

D5W 0.45% NaCl is NOT appropriate for hypernatremia and should be avoided in most cases

For hypernatremia with volume depletion, use D5W (5% dextrose in water) without added sodium, not D5W 0.45% NaCl. The addition of sodium chloride to dextrose solutions defeats the purpose of correcting hypernatremia and can paradoxically worsen the condition by providing additional osmotic load.

Why D5W 0.45% NaCl is Contraindicated in Hypernatremia

The Osmotic Load Problem

Salt-containing solutions should be avoided in hypernatremia because their tonicity creates an excessive renal osmotic load. 1 In conditions like nephrogenic diabetes insipidus where urine osmolality is typically ~100 mOsm/kg H₂O, administering fluids with tonicity of ~150 mOsm/kg (as in 0.45% NaCl) requires approximately 1.5 liters of urine to excrete the osmotic load from just 1 liter of infused fluid, risking serious worsening of hypernatremia. 1

Correct Fluid Choice for Hypernatremia

The recommended treatment for hypernatremia with dehydration is 5% dextrose in water (D5W) without added sodium. 1 This approach works because:

• D5W delivers no renal osmotic load after dextrose metabolism 1
• It provides free water to correct the water deficit that defines hypernatremia 1
• Application at maintenance rates results in slow, controlled decrease in plasma osmolality 1

When D5W 0.45% NaCl IS Appropriate

Diabetic Ketoacidosis (DKA) - After Initial Resuscitation

D5W 0.45% NaCl becomes appropriate only after glucose correction in DKA, not for treating hypernatremia. 1 Specifically:

• Once serum glucose reaches 250 mg/dL during DKA treatment, fluid should be changed to 5% dextrose with 0.45-0.75% NaCl 1
• This prevents hypoglycemia while continuing insulin therapy 1
• The corrected serum sodium should be normal or elevated before using 0.45% NaCl 1

Cirrhosis with Hyponatremia - What to Avoid

In decompensated cirrhosis, 5% dextrose solutions can actually cause or worsen hypervolemic hyponatremia. 1 Excessive hypotonic fluids including 5% dextrose may lead to hyponatremia in these patients due to non-osmotic vasopressin hypersecretion. 1

Proper Management Algorithm for Hypernatremia

Step 1: Assess Volume Status and Sodium Level

• Hypernatremic dehydration indicates water deficiency, not sodium excess 1
• Calculate corrected sodium for any concurrent hyperglycemia 1

Step 2: Choose Appropriate Fluid

For hypernatremia with dehydration:

• Use D5W (5% dextrose in water) as the primary fluid 1
• Calculate initial rate based on physiological demand (maintenance rate) 1
• In adults: 25-30 mL/kg/24h 1
• In children: 100 mL/kg/24h for first 10 kg, 50 mL/kg/24h for 10-20 kg, 20 mL/kg/24h for remaining weight 1

Avoid:

• 0.9% NaCl solutions (tonicity ~300 mOsm/kg) 1
• 0.45% NaCl solutions (tonicity ~150 mOsm/kg) 1
• Any sodium-containing solution in acute hypernatremia 1

Step 3: Monitor Correction Rate

The rate of sodium correction should not exceed 8-10 mEq/L per day to avoid cerebral edema. 1 The induced change in serum osmolality should not exceed 3 mOsm/kg H₂O per hour. 1

Step 4: Adjust Based on Response

• Monitor clinical status, fluid balance, weight, and electrolytes closely 1
• Consider urinary catheter placement for accurate diuresis monitoring 1
• Allow oral intake to thirst when possible 1

Critical Pitfalls to Avoid

Never administer D5W as a bolus in hypernatremia - this risks rapid sodium decrease and brain edema. 1 Slow, controlled administration is essential.

Do not use isotonic fluids for routine hypernatremia management - reserve 0.9% NaCl only for hypovolemic shock requiring acute resuscitation, then immediately transition to free water replacement. 1

Recognize that D5W 0.45% NaCl provides 77 mEq/L of sodium 1 - this is inappropriate when the goal is to provide sodium-free water to dilute elevated serum sodium.