Abstract: | Nitrogen balance studies were performed in the course of parenteral nutrition in the first 5 days of life in three groups of low birth weight newborns (I. group = 12 premature, 27.--30. gestational week, b. w. M = 1298 g, II. group = a) 7 prematures, 27.--31.g.w.,b.w.M = 1295 g,b) 5 small for date prematures, 29.--32.g.w.,b.w.M = 1208 g, III. group = 10 prematures, 31.--36.g.w.,b.w. M = 1751 g). Losses of nitrogen via urine in extreme prematures during the adaptation period are higher than in full term or moderate prematures. Increased volume of parenteral nutrition (glucose, fat emulsion) and increased caloric quotient did not produce a significant restriction of N-losses via urine. No difference was found in N-losses between extreme prematures and small for date prematures of similar birth weight/group IIa): IIb)/. Aminoacids (cca 500 mg N/kg body weight/24 hrs) given on the second day of life were well retained; increased losses of N represented about 20% of N infused. |