Free water deficit
Water deficit in hypernatremia using age- and sex-based total body water.
Inputs
0 of 4SexUsed by the equation
years
Actual (total) body weight
mEq/L
Patient values are shared with every calculator.
When to use
- Hypernatremia.
Pearls and pitfalls
- Does not include ongoing losses.
- Correct chronic hypernatremia by no more than about 10 mEq/L per 24 h.
Why use
Picks the total-body-water fraction from age and sex automatically.
- where
- TBW
- Total body water, L
- Na
- Serum sodium, mEq/L
- f
- 0.6 adult male or child; 0.5 adult female or older male; 0.45 older female