Disturbances in renal function in the postoperative patients are frequently associated with electrolyte composition and volume abnormalities of the body fluids. Renal failure may attend such diverse conditions as extracellular fluid depletion, dehydration, and relative water excess (dilutional hypotonicity). The presence of strong antidiuretic influence in the postoperative state further complicates the interrelation of electrolyte and volume changes. These experiments were performed to simulate conditions obtaining with isotonic extracellular fluid loss and dilutional hypotonicity associated with acute sodium depletion and to examine the effects of these two internal environmental deviations upon the renal excretion of solutes and water.
Two experimental models were used: the first (I), isotonic extracellular fluid (ECF) depletion by duodenal fistula in one series (A) without replacement of the water lost insensibly renally and duodenally, and in another (B), with replacement of the external and insensible fluid losses with a solution of 5% dextrose in water;