Creatinina sanguínea em recém-nascido pré-termo e sua relação com a filtração glomerular

Na prática neonatal é importante a verificação da função de filtração glomerular para que o manuseio de recém-nascidos pré-termo seja facilitado. Métodos específicos são demorados, tecnicamente difíceis, invasivos e dispendiosos. Para tal, métodos simples e eficazes são benvindos. A determinação do clearance de creatinina se encaixa facilmente nestes quesitos. Esta pesquisa teve como objetivo comparar os níveis de creatinina sanguínea no 3o e 7o dias de vida em recém-nascido pré-termo, com o intuito de se mostrar a validade do clearence de creatinina sanguínea como avaliação da função de filtração glomerular renal no período neonatal. Foi realizado um estudo prospectivo durante o ano de 1994, onde foram selecionados 40 recém-nascidos pré-termo (idade gestacional<37semanas), média de 34semanas, peso de nascimento médio de 1840g, na 1a semana de vida. Os critérios de inclusão foram: ausência de malformações nefro-urológicas, hemidinâmica estável, diurese>1ml/h, pressão arterial média normal, saturação de O2 3 92%, ausência de infecções e sem drogas vasoativas. Foram realizadas as determinações da creatinina sanguínea no 3o e 7o dias (método enzimático) e calculados seus respectivos clearances (CCR) através;; da fórmula;*;. As determinações de creatinina situaram-se dentro da faixa de normalidade [3o dia: média: 0,78mg/dl+0,24 e 7o dia: média: 0,67mg/dl+0,31, (p>0,05)] e também de seus respectivos clearances [3o dia: média: 19,5ml/min + 5,2 e 7o dia: média: 23,8ml/min+7,3, (p>0,05)]. Todos os RN evoluíram sem alteração clínica aparente da função renal. Concluindo-se, os resultados deste estudo, quanto à determinação do clearance de creatinina através do cálculo pelo comprimento do recém-nascido, apoiam o emprego deste para uma avaliação aceitável da função de filtração glomerular no período neonatal. ;;;*; ; k = 0,33 para o RNPTFluid management and dosage regimens of drugs in preterm infants should be based on the glomerular filtration rate. The current methods to determine glomerular flitration rate are invasive, time-consuming, and expensive. In contrast, creatinine clearance can be easy obtained and quickly determined. The purpose of this study was to compare plasma creatinine on the third and seventh day of life in preterm newborn infants, to evaluate the influence of maternal creatinine, and to demonstrate creatinine clearance can be used as a reliable indicator of glomerular filtration rate. We developed a prospective study (1994) including 40 preterm newborns (gestational age < 37 weeks), average = 34 weeks; birth weight (average) = 1840 g, in the first week of life. Inclusion criteria consisted of: absence of renal and urinary tract anomalies; O2 saturation 3 92%; adequate urine output (>1ml/kg/hr); normal blood pressure; absence of infections and no sympathomimetic amines in use. A blood sample was collected to determine plasma creatinine (enzymatic method) on the third and seventh day of life and creatinine clearance (CrCl) was obtained using the following equation: ;, k = 0.33 in preterm infant All plasma creatinine determinations showed normal values [third day: 0.78 mg/dl ± 0.24 (mean ± SD)and seventh day: 0.67 mg/dl ± 0.31 - (p>0.05)]. Also all creatinine clearance at third and seventh day of life were normal [third day: 19.5 ml/min ± 5.2 (mean ± SD) and seventh day: 23.8 ml/min ± 7.3 - (p>0,05)]. All preterm infants developed adequate renal function for their respective gestational age. In summary, our results indicate that, for clinical practice, the creatinine clearance, using newborn length, can be used to estimate glomerular filtration rate in preterm newborn infants

Neonatal jaundice: current aspects

Cerca de 1/2 a 2/3 dos recém-nascidos apresentam icterícia clínica durante a 1ª semana de vida. Mesmo os que não demonstram icterícia visível, apresentam níveis de bilirrubina sérica mais elevados do que em outras idades. Os níveis de bilirrubina do sangue de cordão umbilical já são elevados, geralmente de 1 a 2mg/dl, existindo um aumento gradual até 3-4 dias em recém-nascidos de termo e, um pouco mais duradouro, em prematuros, com desaparecimento da icterícia após mais alguns dias em condições normais

Is glycosuria a reliable indicator of adequacy of glucose infusion rate in preterm infants?

CONTEXT: Adequacy of glucose infusion may be monitored via the glycosuria levels, as there is a relationship between glycemia and glycosuria regulated by the renal glucose threshold. In the neonatal period, however, this relationship is not so clear. OBJECTIVE: To evaluate the occurrence of glycosuria in preterm infants submitted to glucose infusion and to verify the relationship between glycosuria and blood glucose level. DESIGN: Accuracy study. SETTING: Neonatal intensive care unit of General Maternity Hospital. PATIENTS: 40 preterm newborns receiving glucose infusion. PROCEDURES: 511 concomitant determinations of glycemia and glycosuria were performed. These 511 pairs were divided into stable and unstable, according to the clinical status of the newborn at the time of data collection, and they were studied in relation to the gestational age, birth weight and glucose infusion rate. RESULTS: The results revealed a greater frequency of glycosuria in gestational age £ 30 weeks, birth weight 6 mg/kg/min. Eight (25.8%) episodes of positive glycosuria occurred in the absence of hyperglycemia, indicating only a moderate concordance between them. CONCLUSION: Glycosuria alone is an unreliable marker of blood glucose concentration and adequacy of glucose infusion rate. It is therefore necessary to monitor blood glucose levels in infants submitted to continuous glucose infusion

Progress in phototherapy

The purpose of this article is to present a recent advance in phototherapy employed on newborn babies with jaundice. The efficacy of this treatment depends on the intensity of emitted light; it is believed that a dose between 6 -12 nm is necessary. The usefulness of phototherapy in healthy, full-term infants is currently being questioned. Therefore, the adequate use of this therapy should be emphasized until a consensus is reached on its advantages and disadvantages