From the Guidelines
For patients with hypernatremia due to decreased fluid intake, administering hypotonic fluids such as 5% dextrose in water (D5W) is recommended, as it provides free water to dilute the elevated sodium concentration without adding a significant renal osmotic load 1.
Key Considerations
- The primary goal is to gradually reduce serum sodium levels by no more than 10 mEq/L in 24 hours to avoid cerebral edema.
- For most adults, starting with D5W at a rate based on physiological demand, such as the routine maintenance rate, is a good approach 1.
- It is crucial to avoid using salt-containing solutions, especially NaCl 0.9% solutions, due to their large renal osmotic load, which can exacerbate hypernatremia 1.
- Close monitoring of weight, fluid balance, and biochemistry is essential to inform adjustments to the rate of administration and fluid composition, especially in patients who cannot self-regulate their fluid intake 1.
Administration Guidelines
- Calculate the initial rate of fluid administration based on a physiological demand, using the routine maintenance rate as a guide 1.
- Monitor serum sodium levels frequently and adjust the administration rate accordingly to avoid overcorrection.
- Consider the patient's ability to self-regulate their fluid intake and adjust the administration strategy accordingly, with ad libitum access to fluid recommended for patients who can self-regulate 1.
Special Considerations
- In patients with concurrent volume depletion, consider starting with isotonic fluids like 0.9% normal saline to restore hemodynamic stability before switching to hypotonic solutions.
- Be aware of the potential for hyperglycemia with 5% dextrose administration and monitor blood glucose levels regularly 1.
From the Research
Treatment of Hypernatremia
To address hypernatremia due to decreased fluid intake, the following points should be considered:
- The goal is to restore the balance of water and electrolytes in the body, correcting the sodium levels without causing rapid shifts that could lead to further complications 2.
- Treatment should focus on the underlying cause of the hypernatremia, which in this case is decreased fluid intake, possibly due to a condition like diabetes insipidus or essential hypernatremia 3, 4.
- For patients with central diabetes insipidus, a common treatment is the administration of desmopressin, a synthetic form of antidiuretic hormone (ADH) 4, 5.
- In cases of hypernatremia, especially when associated with diabetes insipidus, managing fluid balance is crucial. This may involve the use of thiazide diuretics in conjunction with low renal solute feed in neonates to avoid hyponatremia 5.
- The choice of fluid for correction of hypernatremia depends on the severity of the condition and the patient's volume status. Water or hypotonic solutions can be used to correct hypernatremia, but the correction should be done gradually to avoid cerebral edema 2.
Fluid Management
When managing fluids for a patient with hypernatremia due to decreased fluid intake:
- It's essential to monitor the patient's sodium levels closely and adjust the fluid management plan accordingly 2.
- The use of desmopressin in patients with central diabetes insipidus can help regulate fluid balance by reducing urine output, but careful monitoring is necessary to avoid overcorrection and hyponatremia 3, 4.
- In pediatric patients, especially infants, the management of diabetes insipidus and hypernatremia requires careful consideration of their unique needs, including obligate high fluid intake for calorie consumption and the potential need for readjustment of medication dosing as they grow 6.