What is the treatment for high osmolality hypernatremia with hyperglycemia in diabetic hyperosmolar hyperglycemic syndrome (DHHS)?

Treatment for High Osmolality Hypernatremia with Hyperglycemia in DHHS

The treatment for high osmolality hypernatremia with hyperglycemia in diabetic hyperosmolar hyperglycemic syndrome (DHHS) requires aggressive fluid resuscitation with isotonic saline (0.9% NaCl) initially, followed by hypotonic fluids (0.45% NaCl) once hemodynamic stability is achieved, along with continuous insulin infusion and careful electrolyte replacement. 1, 2

Initial Assessment and Fluid Management

• Begin with isotonic saline (0.9% NaCl) at 15-20 ml/kg/h (approximately 1-1.5 L in the average adult) during the first hour to expand intravascular volume and restore renal perfusion 2
• Calculate corrected serum sodium by adding 1.6 mEq to sodium value for each 100 mg/dl glucose >100 mg/dl to accurately assess true sodium status 1
• Monitor effective serum osmolality regularly using the formula: 2[measured Na (mEq/l)] + glucose (mg/dl)/18 1, 2
• After initial resuscitation, switch to 0.45% NaCl (half-normal saline) if corrected serum sodium remains elevated, with a target infusion rate of 4-14 ml/kg/h based on hemodynamic status 1
• For severe hypernatremia with adequate hemodynamic stability, consider alternating 5% dextrose in water (D5W) with isotonic saline 1
• Target fluid replacement should aim to correct estimated deficits within 24 hours, with the induced change in serum osmolality not exceeding 3 mOsm/kg/h 3

Insulin Therapy

• Once hypokalemia (K < 3.3 mEq/l) is excluded, administer continuous intravenous infusion of regular insulin at a dose of 0.1 unit/kg/h (typically 5-7 units/h in adults) 3
• When plasma glucose reaches 300 mg/dl in HHS, decrease insulin infusion to 0.05-0.1 U/kg/h (3-6 U/h) 1, 2
• Add 5-10% dextrose to IV fluids when glucose falls below 300 mg/dl to prevent hypoglycemia while continuing to treat hyperosmolarity 2
• Target glucose level between 250-300 mg/dl until hyperosmolarity resolves 2

Electrolyte Replacement

• Once renal function is assured and serum potassium is known, add 20-30 mEq/L potassium (2/3 KCl and 1/3 KPO₄) to the infusion 3, 1
• Monitor electrolytes (sodium, potassium, chloride, bicarbonate, phosphate, magnesium) every 2-4 hours during initial treatment 1, 2
• Typical total body deficits in HHS include 9 liters of water, 100-200 mEq/kg of sodium, 5-15 mEq/kg of potassium, and 3-7 mEq/kg of phosphate 3

Monitoring and Ongoing Assessment

• Monitor vital signs, mental status, fluid input/output, and hemodynamic parameters hourly 2
• Check blood glucose every 1-2 hours until stable 2
• Successful progress with fluid replacement is judged by hemodynamic monitoring (improvement in blood pressure), measurement of fluid input/output, and clinical examination 3
• In patients with renal or cardiac compromise, more cautious fluid rates with closer monitoring are recommended to avoid iatrogenic fluid overload 1, 2

Special Considerations

• Elderly patients require more cautious fluid administration with closer monitoring due to higher risk of complications 2, 4
• The combination of hyperglycemia and hypernatremia is particularly challenging to manage and may require specialized approaches including free water administration via nasogastric tube in severe cases 5
• Rapid changes in osmolality during treatment may precipitate central pontine myelinolysis, so careful monitoring and gradual correction are essential 4
• ICU admission is indicated for patients with cardiovascular instability, inability to protect airway, obtundation, or acute abdominal signs 6

Transition to Subcutaneous Insulin

• Successful transition from intravenous to subcutaneous insulin requires administration of basal insulin 2-4 hours before the intravenous insulin is stopped 2
• Consider low-dose basal insulin analog in addition to intravenous insulin infusion to prevent rebound hyperglycemia 2