Controlled and prospective studies: 64

Abstract

The protein sparing of exogenous lipid during i.v. alimentation. The prerequisites of a rational nutritional design for prematures receiving total parenteral nutrition (TPN) are the: (a) estimation of coverage of the energy cost of basal metabolism muscular activity, chemical thermogenesis and growth by the metabolizable energy (ME) intake. (b) estimation of the desirable protein and fat deposition for optimal growth and development. Using nutrient balance, indirect calorimetry (IC) and urinary nitrogen output (UN), the coverage of energy metabolism by carbohydrate (CHO), protein (P) and fat (F) were determined by studying 36 infants during (TPN). The majority of patients were 2-3 day postoperative surgical; mean gestational age 36 weeks, birth weight 2600 g, postnatal age 16 days. During initial hypocaloric infusion (18-35 Kcallkglday) of glucose (GL) the nitrogen balance was negative (-70 mglkglday). GL + amino acid (AA) infusion resulted in a positive nitrogen balance and correlated significantly with the daily protein intake (y = 0.61 X + 0.17; r = 0.54; p< 0.01; n=19) which varied between 0.5 -3.5 g/kg/day. By increasing the caloric intake with Intralipid (IL) at a fixed protein intake nitrogen retention was increased ( 51 mglkglday), resulting in 0.3 glkglday extra protein deposition. Over 50-60% of the IL was oxidized. These results suggest that this protein sparing is attributable to the preferential utilization of fat for energy metabolism. A nasogastric load of 2,7 glkg of lipids with 67 % of medium chain triglycerides and 30 % of grape seeds oil was given at the age of 48 hours to 20 preterm neonates (mean bw = 2164 g ; gest. age : 35 weeks). Its effect on the concentrations of plasma glucose free fatty acids (FFA), serum B-OH-butyrate (BOHB) and lactate was compared to their evolution in I I control preterm infants (mean bw 2102 g ; gest. age : 35 weeks). The basal levels were similar in