OBJECTIVE: To identify the determinants associated with uremia elevation in the first days of life in extremely premature infants. METHODS: We performed a prospective cohort study in a cohort of neonates born at less than 30 weeks of gestation. RESULTS: Forty-eight preterm infants were included, of which 10 died. The mean fluid administration was 55, 72, 88 and 124 mL/kg on the first, second, third and seventh days of life. Amino acid doses were low in the first two days of life and were unrelated to uremia elevation. Thirty-one percent of the infants presented hypernatremia. Uremia was measured in 31 infants between the fifth and tenth days of life and 12 infants (38.7 %) had uremia values of 100 mg/dL or higher, without creatinine elevation. All of these infants were born at less than 27 weeks of gestation, weighed less than 850 grams at birth, and showed greater weight loss (19.2 % vs. 13.8 %; p 5 0.037) and higher natremia (150.2 mEq/L vs. 146.6 mEq/L; p 5 0.023). The use of furosemide increased the risk of elevated uremia (relative risk: 2.54; 95 % confidence interval: 1.05 6.14). CONCLUSIONS: Total uremia of 100 mg/dL or higher was associated with dehydration, greater weight loss, higher natremia, furosemide use, lower gestational age, and lower birth weight.
OBJECTIVE: To identify the determinants associated with uremia elevation in the first days of life in extremely premature infants. METHODS: We performed a prospective cohort study in a cohort of neonates born at less than 30 weeks of gestation. RESULTS: Forty-eight preterm infants were included, of which 10 died. The mean fluid administration was 55, 72, 88 and 124 mL/kg on the first, second, third and seventh days of life. Amino acid doses were low in the first two days of life and were unrelated to uremia elevation. Thirty-one percent of the infants presented hypernatremia. Uremia was measured in 31 infants between the fifth and tenth days of life and 12 infants (38.7 %) had uremia values of 100 mg/dL or higher, without creatinine elevation. All of these infants were born at less than 27 weeks of gestation, weighed less than 850 grams at birth, and showed greater weight loss (19.2 % vs. 13.8 %; p 5 0.037) and higher natremia (150.2 mEq/L vs. 146.6 mEq/L; p 5 0.023). The use of furosemide increased the risk of elevated uremia (relative risk: 2.54; 95 % confidence interval: 1.05 6.14). CONCLUSIONS: Total uremia of 100 mg/dL or higher was associated with dehydration, greater weight loss, higher natremia, furosemide use, lower gestational age, and lower birth weight.