Water Deficit in Hypernatremia

 

Input
 

Age Sex Factor	Male <65 years old (0.6)
	Male ≥65 years old (0.5)
	Female <18 years old (0.6)
	Female 18-65 years old (0.5)
	Female ≥65 years old (0.45)
Desired Na		mEq/L
Normal Weight		gm kg lb mg
Serum Na		mEq/L

 

Result
 

WDef		L fL mL
Decimal Precision   0 1 2 3

 

Notes

• The default unit of measure for weight is kilograms. Please verify that the correct unit of measure has been selected.
• The term Age Sex Factor * Normal Weight represents the normal total body water (TBW).
• Normal TBW is gender and age specific as seen in the 0.6, 0.5 and 0.45 factors above.

 
Equations used
 

WDef = (AgeSexFactor * NormalWeight) * (SerumNa - DesiredNa) / DesiredNa

 

Calculation Details and Variables

• Equation parameters such as Age Sex Factor, have two or more discrete values that may be used in the calculation. The numbers in the parentheses, e.g. (0.6), represent the values that will be used.

 

References

1. Adrogue HJ, Madias NE. Hypernatremia. N Engl J Med. 2000 May 18;342(20):1493-9. PubMed ID: 10816188