Hypernatremia reflects a deficit in the total amount of water in the body in relation to the total sodium content. The free water deficit is used to access the amount of water replacement needed to correct hypernatremia.
Calculator of free water deficit
Free water deficit = TWB * ( Current Sodium / Desired Sodium – 1)
- TWB (Adult Male) = 0.6 x Weight
- TWB (Adult Female) = 0.5 x Weight
- TWB (Elderly Male) = 0.5 x Weight
- TWB (Elderly Female) = 0.45 x Weight
- TWB (Child) = 0.6 x Weight