Parenteral nutrition and immature neonates. Comparative study of neonates weighing under 1000 and 1000-1250 g at birth.

UNLABELLED: We studied the nutritional requirements of 53 neonates with a birth-weight of 1250 g or less and analysed the parenteral and enteral nutrition provided, the weight-gain curves, the incidence of prior pathology and complications. We compared those weighing under 1000 g at birth (n=25) with those weighing 1001-1250 g (n=28). All neonates received central parenteral nutrition at an average age of 42.3 h. The liquid requirements of the lower birth-weight group were significantly greater. No differences were found in the supply of glucose, proteins, lipids and calories until after the first 15 days of life, when the <1000 g group required a greater liquid and caloric intake. Parenteral nutrition was suspended earlier for the >1000 g group (32.6 vs. 48.1 days). Maximum weight loss (12.56%) for the two groups occurred at 5.23 days. No differences in weight gain (g/kg/day) between the groups were observed. The >1000 g group began enteral nutrition significantly earlier and presented greater tolerance. The incidence of complications (bronchopulmonary dysplasia, enterocolitis, nosocomial sepsis, Candidas A sepsis, osteopenia) was greater in the lower birth-weight group, as was that of hyaline membrane disease and mechanically assisted respiration. There were no differences in the incidence of intracraneal haemorrhage, ductus arteriosus, early sepsis, delayed intrauterine growth or hypoglucemia. CONCLUSIONS: The severity of the initial pathology and the greater incidence of complications among the lower birth-weight neonates (<1000 g) influenced both the need for parenteral nutrition and the reduced tolerance to enteral nutrition. Although the rate of weight gain was similar for the two groups, the <1000 g group required a longer period of parenteral nutrition.

Beta-2-microglobulin in the assessment of renal function in full term newborns following perinatal asphyxia.

In order to evaluate the clinical usefulness of serum and urinary beta 2 microglobulin (beta 2-m) determination as a marker of renal damage following perinatal asphyxia, twenty asphyxiated and twenty healthy full term newborns were studied. Renal function was monitored on the first and third day after birth by traditional tests such as creatinine (Cr), endogenous creatinine clearance (Ccr), and fractional Na excretion (FeNa), as well as by serum and urinary beta 2 microglobulin. The value of different tests for the diagnosis of oliguria and of acute renal failure was determined. Eleven asphyxiated neonates developed oliguria and five ARF in contrast to none of the controls. Both traditional tests of renal function, and determinations of beta 2-m with the exception of serum beta 2-m, were significantly different (p less than 0.01) between controls and asphyxiated neonates. When stratified analysis was performed, only serum cr, urinary beta 2-m/cr ratio, and Fe beta 2-m were able to discriminate oliguria from preserved diuresis on the first day of life. For ARF, only Ccr and Fe beta 2-m were different, again on the first day of life. Urinary beta 2-m/creatinine ratio and Fe beta 2-m appear to be more sensitive and specific for the early detection of proximal tubular renal dysfunction following perinatal asphyxia than usual tests of renal function.