A 35 year old, 70 kg female presents with sodium =160 mEq/L. Calculate the free water deficit for this patient:

Approximate percentage water of total body mass. Patient % Children 60 Non-elderly males 60 Non-elderly females 50 Elderly males 50 Elderly females 45 Water deficit=Total body water x (current sodium -140)/140 TBW(female) = 0.5 x weight = 35 L for the patient mentioned in question Water deficit =35 x (160-140)/140 Water deficit = 5 liters