Sodium Correction Rate for Hyponatremia
Rate of fluid administration in correction of hyponatremia
Hyponatremia is a common electrolyte disturbance frequently requiring fluid administration for correction to physiologic levels. Rapid correction can be dangerous for patients, leading to cerebral edema and osmotic demyelination among other complications.1 Determining a safe rate of fluid administration to prevent these issues relies on patient and fluid variables. The majority of cases of osmotic demyelination were originally thought to have taken place with daily sodium correction of greater than 12 mmol/L/day (0.5 mmol/L/hr); however, many experts advocate for a more conservative approach to correction, targeting 4-6 mmol/L/day with a maximum of 8 mmol/L/day.2
Formula for Sodium Correction
- Fluid rate (mL / hour) = [(1000) * (rate of sodium correction in mmol / L / hr)] / (change in serum sodium)
- Change in serum sodium = (preferred fluid selected sodium concentration - serum sodium concentration) / (total body water + 1)
- Total body water = (weight in kg) * (% body water), whereby % of body water is 0.6 in children and adult males, 0.5 in adult females and elderly males, and 0.45 in elderly females).