Fluid and Electrolyte Requirements and Tolerance

Abstract

Twenty-five years association with the Children’s Service, much of it concerned with how to devise better means to support the child during a period when critical illness precludes his taking nourishment in the ordinary fashion, have taught me to approach the assigned topic with caution and humility. One lesson learned is that neither requirement nor tolerance for any individual component of a parenteral fluid mixture is constant, a change in one affecting the metabolism of others. Perhaps even more obviously, the results of experiments on normal adult individuals cannot be directly extrapolated to the sick infant for age, size, medications and the illness itself affect both requirement and tolerance. Because my own particular focus has been principally on water metabolism, the time allotted will be devoted to a personal review of the development of knowledge in this circumscribed area attempting to make clear the need for a dynamic approach to the handling of any particular component of a parenteral fluid mixture, be it water, glucose, fat or phosphate.