The use of electrical conductivity measurement in the calculation of ion-free water loss in urine.
The urine electrical conductivity is a practical guide to the ion-to-water ratio of urine. It may be used to assess the influence of urinary loss upon the total body ion-to-water ratio. It is suggested that the total body ion-to-water ratio is the object of control in water therapy, commonly administered as 5% dextrose. The total body ion-to-water ratio closely accords with the ratio in the extracellular fluid. Since sodium is the predominant extracellular cation, the plasma sodium concentration closely reflects the extracellular and total body ion-to-water ratio. As a consequence the urine electrical conductivity may be used as a continuous signal in the open or closed loop control of water balance as reflected by the plasma sodium concentration.
Intensive Care Unit, St. Frances Xavier Cabrini Hospital, Melbourne, Australia.
W G
WG
Parkin
R W
RW
Dickinson
D003422:Critical Care; D004553:Electric Conductivity; D005440:Fluid Therapy; D006801:Humans; D011188:Potassium / Q000652:urine*; D012964:Sodium / Q000652:urine*; D014882:Water-Electrolyte Balance
D012964:Sodium; D011188:Potassium