Changes in total body water in infants receiving total intravenous nutrition

Body fluid compartment changes following neonatal surgery

The neonate is born with an excess of total body water (TBW) in the range of 75% to 85% of body weight (v 60% in the adult), which is due to a large extracellular fluid volume (ECF) of 40% to 50% of body weight (v 20% in the adult). In an attempt to define the changes that occur in TBW and ECF following neonatal surgery, the following prospective study was carried out. Twenty newborns with major congenital anomalies (gastroschisis, 10; esophageal atresia, 4; ileal atresia, 3; omphalocele, 2; and malrotation, 1) were studied weekly for 4 weeks following surgery while being maintained on a standard protocol of total parenteral nutrition (TPN). Total body water was measured using deuterium oxide, and extracellular fluid volume was assayed with sodium bromide; both were expressed as percent body weight (BW). Weight gain or maintenance was observed in all infants. TBW remained unchanged (from 85.4% to 83.0%), and ECF decreased from 51.2% to 36.7% during the observation period. The TBW in the ten gastroschisis infants decreased from 87.3% to 78.0% v the ten other newborns, in whom there was no change (84.0% to 85.0%). The ECF changes were more dramatic, decreasing from 51.6% to 32.3% in the gastroschisis infants, v 50.8% to 45.5% in the other neonates (P = .0156). There were no differences between the two groups in the intake and output of fluids. The following conclusions were drawn: (1) Following major surgery, newborns show a steady decrease in ECF and minimal change in TBW in spite of adequate weight gain while receiving TPN.(ABSTRACT TRUNCATED AT 250 WORDS)

Changes in the body composition of the surgical infant in the early postoperative period

The purpose of this study was to evaluate the effects of postoperative nutritional management on the body composition of infants after major surgery. We studied 13 full-term surgical infants (mean initial weight 2.88 +/- 0.19 kg; mean days postsurgery 5.0 +/- 0.5). Ten infants were receiving total parenteral nutrition and three were orally fed (mean caloric intake 84 +/- 4 kcal/kg/d; mean fluid intake 145 +/- 4 mL/kg/d). Total body water (TBW) was measured by isotope dilution using heavy oxygen (18O) labeled water (H2(18)O). Total body fat (TBF) was estimated from anthropometric data. Lean body mass (LBM) was calculated as follows: LBM = weight--TBF. Protein, fat, and carbohydrate accretion were determined by energy and macronutrient balance in conjunction with open-circuit indirect calorimetry. Body composition was reevaluated after an interval of seven days. Body weight increased from 2.88 +/- 0.19 to 3.00 +/- 0.19 kg, representing a mean growth velocity of 5.9 g/kg/d. Increments were observed in all body compartments but only the increase in TBF reached statistic significance (12.9 v 14% of body weight, P less than .05). TBW ranged from an initial value of 76.2 +/- 1.4% to a value of 75.5 +/- 1.4% at the end of the study. Protein, fat, and carbohydrate accretion (g/kg/d) during the seven-day study period were 1.62 +/- 0.13; 1.44 +/- 0.41, and 0.96 +/- 0.70, respectively. These data indicate that in the early postoperative period, the weight gain is secondary to both water and solid tissue accretion. Fat represents the major form of energy storage in the new tissues synthesized.(ABSTRACT TRUNCATED AT 250 WORDS)

Changes in total body water and extracellular fluid volume in infants receiving total parenteral nutrition

The nature of weight gain seen in infants receiving total parenteral nutrition continues to be controversial. The debate centers around whether or not the weight gain represents an increase in body mass or water retention. The following study was carried out to answer this question. Eighteen infants receiving peripheral or central intravenous nutrition following major surgery were studied for periods ranging from 1 to 17 weeks. The following studies were carried out after receiving informed consent from the parents and in accordance with the standards established by the Human Use Committee. Total body water was measured using the nonradioactive isotope, deuterium oxide; extracellular fluid volume was assayed using the nonradioactive isotope, sodium bromide. Both body fluid compartments were calculated using the Fick principle of dye dilution. Following double vacuum distillation, serum deuterium oxide was assayed using the falling drop technique. Serum bromide was measured by a technique developed in our laboratory that involves the complexing of bromide with gold chloride and the measurement of this chemical complex colorimetrically. Weight gain was observed in all patients. Total body water percent body weight was 82% +/- 15% prior to the initiation of intravenous nutrition; it decreased within the first week to 71% +/- 12% and then stabilized for the remainder of the study period at 75% +/- 7%. The extracellular fluid volume percent body weight was 56% +/- 15% prior to the start of intravenous nutrition; it fell to 47% +/- 10% during the first week of parenteral nutrition, and then stabilized at 40% +/- 9%.(ABSTRACT TRUNCATED AT 250 WORDS)

Parenteral 20% safflower oil emulsion safety and effectiveness as a caloric source in newborn infants

Five surgical infants, ages 3 to 30 days, were studied while receiving peripheral total parenteral nutrition for a period of 2 weeks. By a randomized sequence, either 10 or 20% safflower oil emulsion was infused the first week, followed by the alternate solution during the second week. Caloric intake was 80 to 100 cal/kg/day, of which lipids comprised one-third to one-half. No adverse side effects were noted. Eosinophilia developed in three patients, but otherwise no changes in hematologic and biochemical parameters, including liver enzymes, were noted. Weight gain averaged 11.1 g/kg/day during the study period and was similar for the 10 and 20% solutions. Intravenous fluid intake averaged 21 ml/kg/day less during the week of the patients received 20% fluid emulsions. The 20% safflower oil emulsion proved comparable to the 10% solution in both safety and efficacy and enabled significant reduction of fluid intake while maintaining infused caloric levels.

Nutritional support of the critically ill child

New techniques for meeting the special metabolic requirements of the pediatric patient and the specific nutritional needs created by different disease states have become available both in enteral feeding and parenteral nutrition. Assessment of nutritional status and requirements of critically ill children are outlined, and the indications, techniques of administration, and complications of the available nutritional modalities are discussed.