From the Guidelines
To correct hypernatremia, the initial rate of fluid administration should be calculated based on a physiological demand, and a routine maintenance rate can be used as a starting point, such as 100 mL/kg/24 h for the first 10 kg in children. For example, in a child weighing 10 kg, the initial rate would be 100 mL/kg/24 h, which translates to 1000 mL/24 h or approximately 41.7 mL/h. However, if you want to use a fixed rate like 100 mL/hour, you should first calculate if this rate will achieve the appropriate correction. The formula to calculate the infusion rate is not directly provided in the study 1, but the study recommends using water with dextrose (for example, 5% dextrose) and calculating the initial rate of fluid administration based on a physiological demand. In this case, using 100 mL/hour would deliver 2400 mL in 24 hours, which may be reasonable depending on the patient's weight and physiological demand. Frequent monitoring of serum sodium (every 4-6 hours initially) is essential to adjust the rate as needed and prevent overly rapid correction, as recommended in the management of hypernatremic dehydration in patients with nephrogenic diabetes insipidus 1. Some key points to consider when correcting hypernatremia include:
- Using water with dextrose (for example, 5% dextrose) to avoid large renal osmotic load
- Calculating the initial rate of fluid administration based on a physiological demand
- Monitoring serum sodium frequently to adjust the rate as needed
- Avoiding salt-containing solutions, especially NaCl 0.9% solutions, due to their large renal osmotic load 1.
From the Research
Hypernatremia Correction Formula
The formula for hypernatremia correction is not directly provided in the given studies. However, the studies suggest the following:
- The rate of correction of hypernatremia should not exceed 0.5 mmol/L per hour 2
- The total correction in 24 hours should not exceed 10-12 mmol/L 3
- In some cases, a correction rate of up to 8,10, or 12 mmol/L per 24 hours may be used 2
Example of Hypernatremia Correction
To calculate the amount of free water needed to correct hypernatremia, the following formula can be used: Total body water (TBW) x (current sodium - desired sodium) / desired sodium However, this formula is not explicitly mentioned in the provided studies.
Fluid Administration
The studies suggest the following:
- Free water can be administered via a nasogastric (NG) tube to improve free water deficit 4
- Dextrose 5% in water and Ringer's lactate can be used to treat dehydration and hypernatremia 4
- Desmopressin can be used to improve free water deficit and correct hypernatremia 5, 4
Rate of Fluid Administration
The studies do not provide a specific rate of fluid administration for hypernatremia correction. However, they suggest that:
- The rate of correction should be carefully monitored to avoid overcorrection or undercorrection 2, 3
- The administration of fluids should be tailored to the individual patient's needs and response to treatment 4
Example of Fluid Administration Rate
A rate of 100 ml/h may be used, but this is not explicitly mentioned in the provided studies. The rate of fluid administration should be determined based on the individual patient's needs and response to treatment.