OBJECTIVE: The purpose of the study was to investigate alimentation of very low birth weight (VLBW) infants and its effect on blood concentration of glucose, urea nitrogen, creatinine and potassium. METHODS: The subjects were 100 VLBW infants born between 1993-1999. The gestational age ranged from 23 to 32 weeks and the birth weight from 443 to 1470 g. Intravenous glucose infusions were begun shortly after birth, amino acids on day 3 and lipids on day 4. Blood samples were drawn for determinations of urea nitrogen, creatinine and potassium. RESULTS: Mean caloric intake of glucose rose from 24.7 kcal/kg/day on day 1 to 58.1 kcal/kg/day on day 8 (p < 0.0001) and of amino acids from 1.1 g/kg/day on day 3 to 1.9 g/kg/day on day 8 (p < 0.0001). Potassium administration increased from 1 mq/kg/day on day 2 to 1.9 mq/kg/day on day 8. Urea nitrogen was at a mean level of 21.4 mg/dl on day 4 and declined afterwards (p < 0.0001). Serum potassium levels declined from 5.9 mmol/L on day 2 to 4.1 mmol/L on day 8 (p < 0.0001), while creatinine levels remained stable. CONCLUSION: Our findings suggest that a catabolic state in VLBW infants begins to be reversed when the caloric intake of 40-50 kcal/kg/day is achieved.
OBJECTIVE: The purpose of the study was to investigate alimentation of very low birth weight (VLBW) infants and its effect on blood concentration of glucose, ureanitrogen, creatinine and potassium. METHODS: The subjects were 100 VLBW infants born between 1993-1999. The gestational age ranged from 23 to 32 weeks and the birth weight from 443 to 1470 g. Intravenous glucose infusions were begun shortly after birth, amino acids on day 3 and lipids on day 4. Blood samples were drawn for determinations of ureanitrogen, creatinine and potassium. RESULTS: Mean caloric intake of glucose rose from 24.7 kcal/kg/day on day 1 to 58.1 kcal/kg/day on day 8 (p < 0.0001) and of amino acids from 1.1 g/kg/day on day 3 to 1.9 g/kg/day on day 8 (p < 0.0001). Potassium administration increased from 1 mq/kg/day on day 2 to 1.9 mq/kg/day on day 8. Ureanitrogen was at a mean level of 21.4 mg/dl on day 4 and declined afterwards (p < 0.0001). Serum potassium levels declined from 5.9 mmol/L on day 2 to 4.1 mmol/L on day 8 (p < 0.0001), while creatinine levels remained stable. CONCLUSION: Our findings suggest that a catabolic state in VLBW infants begins to be reversed when the caloric intake of 40-50 kcal/kg/day is achieved.