*2.2.4 Treatment*


*Free Water Deficit* <sup>¼</sup> *Total Body Water*% � *Weight in kgs* ð Þ� *Curent Sodium Ideal Sodium* � <sup>1</sup> (2)

\* TBW is:

Adult Male: 60%; 50% in elderly.

**Figure 3.**

*Diagnostic approach for hypernatremia.*

Adult Female: 50%; 45% in elderly.

• Through hospitalization, patients will have ongoing water losses which includes insensible losses (stool, sweat, respirations) and urine free water that should be accounted for. Insensible losses cannot be measured therefore can be approximated as 30-50 ml/hr [25, 26]. Urine free water can be calculated (see Eq. 3):

*Urine Free Water clearance ml* ð Þ¼ *=hr Urine flow rate*

� *Urine flow rate* � ð*Urine sodium* <sup>þ</sup> *Urine Potassium*<sup>Þ</sup> *Serum Sodium* (3)

• For acute or chronic hypernatremia, serum sodium should be measured every 4-6 hours and the estimated fluid replacement rate should be adjusted accordingly.
