From the Guidelines
After acutely treating hyperosmotic hyperglycemic syndrome (HHS), continue managing hypernatremia by administering hypotonic fluids like 0.45% saline or 5% dextrose in water (D5W) at a controlled rate, with a maximal reduction in osmolality of 3 mOsm kg–1 H2O h–1, as recommended by the position statement on hyperglycemic crises in diabetes 1.
Key Considerations
- The correction rate should not exceed a certain threshold to prevent cerebral edema and osmotic demyelination syndrome, although the exact rate is not specified in the provided evidence, a general consensus is to not exceed 10 mEq/L per day (or 0.5 mEq/L per hour) in clinical practice.
- Regular monitoring of serum sodium levels every 2-4 hours is essential during correction to avoid over-correction or under-correction.
- Calculate the free water deficit using the formula: Free water deficit = Total body water × [(measured Na⁺/desired Na⁺) - 1], where total body water is approximately 60% of body weight in men and 50% in women, and replace this deficit gradually over 48-72 hours.
Treatment Approach
- Maintain euglycemia with insulin as needed, as hyperglycemia can contribute to hypernatremia through osmotic diuresis, and consider adding dextrose to the hydrating solution once blood glucose reaches 250 mg/dl, as suggested by the position statement on hyperglycemic crises in diabetes 1.
- Ensure adequate fluid intake once the patient can take oral fluids safely, and identify and treat the underlying cause of hypernatremia, which may include diabetes insipidus, excessive sodium intake, or inadequate water intake.
Complications Prevention
- Be aware of the potential complications of DKA and HHS, including hypoglycemia, hypokalemia, and hyperglycemia, as well as cerebral edema, which is a rare but frequently fatal complication, and take preventive measures such as gradual replacement of sodium and water deficits and the addition of dextrose to the hydrating solution, as recommended by the position statement on hyperglycemic crises in diabetes 1.
From the FDA Drug Label
Removal of excess free body water increases serum osmolality and serum sodium concentrations. All patients treated with tolvaptan, especially those whose serum sodium levels become normal, should continue to be monitored to ensure serum sodium remains within normal limits If hypernatremia is observed, management may include dose decreases or interruption of tolvaptan treatment, combined with modification of free-water intake or infusion.
To continue treating hypernatremia after acute management of hyperosmolar hyperglycemic syndrome (HHS), the following steps can be taken:
- Monitor serum sodium levels to ensure they remain within normal limits
- If hypernatremia is observed, consider:
- Dose decreases of tolvaptan
- Interruption of tolvaptan treatment
- Modification of free-water intake or infusion 2
From the Research
Treatment Approach
To continue treating hypernatremia after acute management of hyperosmolar hyperglycemic syndrome (HHS), the following steps can be taken:
- Correct the underlying cause of hypernatremia 3, 4, 5, 6
- Replace the free water deficit with hypotonic infusions, such as dextrose 5% in water and ringer's lactate 3, 4, 5
- Administer free water via a nasogastric (NG) tube or intravenously 3, 5
- Use desmopressin (Minirin) to improve free water deficit, especially in cases of central diabetes insipidus or essential hypernatremia 3, 7
Rate of Correction
It is crucial to correct hypernatremia at a rate that avoids rapid changes in serum sodium concentration, which can lead to osmotic demyelination syndrome 4, 5.
- For acute hypernatremia (< 24 hours), hemodialysis can be an effective option to rapidly normalize serum sodium levels 4
- For preexisting hypernatremia (> 48 hours), the correction rate should not exceed 8-10 mmol/L/day 4
Monitoring and Adjustment
Close laboratory controls are essential to monitor the correction of hypernatremia and adjust the treatment approach as needed 4, 5.