From the Guidelines
For patients with hypernatremia, water or dextrose-containing solutions, such as 5% dextrose, are recommended as the initial fluid of choice, as they provide free water to help correct the sodium imbalance without adding to the renal osmotic load. The use of salt-containing solutions, especially NaCl 0.9% solutions, should be avoided due to their high renal osmotic load, which can exacerbate hypernatremia 1. In patients with congenital nephrogenic diabetes insipidus (NDI), ad libitum access to fluid is recommended to prevent dehydration, hypernatremia, growth failure, and constipation, with the optimal amount of fluid best determined by the patient's own thirst sensation 1.
Key considerations in fluid management for hypernatremia include:
- Avoiding isotonic fluids for maintenance, as they can worsen hypernatremia
- Using water or dextrose-containing solutions to provide free water and correct sodium imbalance
- Monitoring urine output, fluid balance, and electrolytes closely, especially in hospitalized patients
- Adjusting fluid composition and rate based on individual patient needs and response to treatment 1.
In general, the goal of fluid management in hypernatremia is to provide sufficient free water to correct the sodium imbalance while avoiding further exacerbation of the condition. This approach prioritizes the patient's morbidity, mortality, and quality of life outcomes.
From the Research
Hypernatremia and Associated Fluid Type
- Hypernatremia is often caused by dehydration resulting from an impaired thirst mechanism or lack of access to water, and other causes such as diabetes insipidus 2, 3, 4.
- The treatment of hypernatremia involves addressing the underlying cause and correcting the fluid deficit, with hypotonic fluid replacement being necessary when sodium is severely elevated 2, 3, 5, 4.
- Hypotonic fluids are used to replace the loss of free water, and the rate of correction depends on the rapidity of hypernatremia development 3, 5, 4.
- Electrolyte-free water replacement is the preferred therapy, though electrolyte (sodium) containing hypotonic fluids can also be used in some circumstances 4.
Key Considerations for Fluid Replacement
- The type of replacement solution should be selected based on the underlying cause of hypernatremia and the patient's volume status 5.
- The amount and rate of water administration should be determined based on the severity of hypernatremia and the patient's clinical condition 5, 4.
- Frequent monitoring of plasma sodium levels is essential to ensure appropriate response and to adjust the rate of fluid replacement to prevent the risk of cerebral edema from rapid correction of chronic hypernatremia 3, 4.