The Maintenance Need for Water in Parenteral Fluid Therapy, by Malcolm A. Holliday, MD, and William E. Segar, MD,Pediatrics, 1957;19:823–832

Abstract

One of the major objectives of parenteral fluid therapy is provision of water to meet physiologic losses. These losses, the insensible and urinary losses, have been extensively studied and defined for infants and adults. It is established from these studies that both insensible loss of water and urinary water loss roughly parallel energy metabolism and do not parallel body mass (weight). Therefore, any values that are applicable to all ages must be derived from some function of energy metabolism. Initially, and to a large extent even today, needs for water have been determined on the basis of weight in infants and on the basis of total amounts in adults. Although this serves well for infants and adults, the hapless individual between these two groups receives, at best, a rough estimate of his requirement for water. Crawford and his associates have referred needs for water, and a variety of drug dosages as well, to a unit of surface area (SA) because SA closely parallels basal energy metabolism. In this system SA is computed from a height-weight nomogram. It is generally agreed that the maintenance requirements for water of individuals is determined by their caloric expenditure. By means of the following formulae, the caloric expenditure of hospitalized patients can be determined from weight alone. For weights ranging from 0 to 10 kg, the caloric expenditure is 100 cal/kg/day; for weights ranging from 10 to 20 kg the caloric expenditure is 1000 cal plus 50 cal/kg for each kilogram of body weight >10; for weight >20 kg the caloric expenditure is 1500 cal plus 20 cal/kg for each kilogram >20. Maintenance requirements for water depend on insensible loss of water and renal loss. An allowance of 50 mL/100 cal/day will replace insensible loss of water, and 66.7 mL/100 cal/day will replace renal losses. As water of oxidation will supply approximately 16.7 mL/100 cal/day, the remaining 100 mL/100 cal/day must be supplied to meet the remaining water losses of patients on parenteral fluid therapy. Possible exceptions to this figure are discussed. Maintenance requirements of sodium, chloride, and potassium are 3.0, 2.0, and 2.0 mEq/100/cal/day, respectively.