Application of Homeostatic Principles to the Practice of Parenteral Fluid Therapy

THE comments on parenteral fluid therapy that follow are based on the fact that there are limits to the body's capacity to conserve and to eliminate, in accordance with homeostatic needs, water and solutes given either orally or parenterally.1 , 2 For each substance there is a physiologic minimum requirement, which is the least intake of the substance in question needed to balance output and hence to prevent deficits when conservation forces are acting maximally. There is also for each substance a physiologic maximum tolerance, defined as the largest amount of the substance that can be taken and eliminated without seriously disturbing . . .