From the Guidelines
To correct hypernatremia, 0.45% sodium chloride (half-normal saline) is an appropriate choice for patients with hypernatremia who are euvolemic or hypervolemic, as it provides some sodium while also delivering free water to gradually reduce serum sodium concentration. The provided evidence 1 focuses on the management of diabetic ketoacidosis (DKA) but touches on fluid replacement strategies that can be applied to hypernatremia correction. According to the study, for patients with normal or elevated corrected serum sodium, 0.45% NaCl infused at 4–14 ml kg–1 h–1 is appropriate 1.
When considering the correction of hypernatremia, it's crucial to calculate the free water deficit and replace it gradually over 48-72 hours to avoid cerebral edema and neurological complications. The correction rate should not exceed 10 mEq/L per day (or 0.5 mEq/L per hour). A typical adult infusion rate would be 100-125 mL/hour of 0.45% NaCl, but this should be adjusted based on the patient's specific sodium level, weight, and clinical condition.
Key points to consider in the management of hypernatremia include:
- Monitoring serum sodium levels every 2-4 hours initially, then every 4-6 hours as the patient stabilizes.
- Adjusting the infusion rate based on the patient's response to therapy.
- Discontinuing any medications contributing to hypernatremia and addressing the underlying cause while fluid correction is ongoing.
- Considering the addition of dextrose 5% in water (D5W) for patients with severe hypernatremia (>160 mEq/L) or adjusting the infusion rate accordingly.
The goal is to achieve a balanced correction that prevents too rapid a change in serum osmolality, thereby minimizing the risk of complications such as cerebral edema. By following these guidelines and adjusting treatment based on individual patient needs, clinicians can effectively manage hypernatremia and improve patient outcomes.
From the Research
Hypernatremia Correction with 0.45 NaCl
- The use of 0.45 NaCl for hypernatremia correction is a common practice, but the optimal rate of correction is still a topic of debate 2, 3.
- A study published in Kidney360 found that slow correction of hypernatremia (≤0.50 mEq/L/hour) was associated with lower in-hospital mortality, but higher odds of discharge to hospice or nursing facilities 2.
- Another study published in Critical Care found that the goal of treatment for hypernatremia is to reduce cerebral symptoms, and that correction above 10 mmol/l/day should be avoided to reduce the risk of osmotic demyelination 3.
- The rate of hypernatremia correction should not exceed 12 mmol/l/day to reduce the risk of rebounding brain edema 3.
- A systematic review published in Cureus found that the present recommendations for treating acute and chronic hypernatremia in resuscitated patients do not stem from high-quality research 4.
Key Considerations
- The management of hypernatremia focuses on resolving the underlying cause, replenishing free water deficit, and preventing further losses while closely monitoring serum sodium concentration 4.
- Multiple combined mechanisms are common in hypernatremia, and more than one mechanism must be considered for safe and lasting correction 3.
- The risk of overcorrection is associated with the mechanisms that cause hypernatremia, and traditional classifications according to volume status are notoriously difficult to handle in clinical practice 3.