Importância clínica da dosagem de lactato e contagem de eritroblastos no sangue colhido no segmento placentário da veia umbilical para o diagnóstico de hipóxia-isquemia em prematuros Clinical value of lactate measurement and nucleated red blood cell counts in the placental segment of the umbilical vein of premature newborns for diagnosis of hypoxia-ischemia

Abstract

OBJETIVO: Determinar a validade clínica das dosagens de lactato e contagem de eritroblastos quando comparados com o excesso de bases (EB) em sangue do segmento placentário da veia umbilical de prematuros. MÉTODOS: foram colhidas amostras de 25 prematuros, após ligadura e dequitação. Os prematuros foram seguidos até a alta. Estatística incluiu regressão linear, correlação de Spearman, curvas ROC, Teste de Fisher. RESULTADOS: Lactato mostrou boa correlação com pH e EB (p OBJECTIVE: To evaluate the clinical value of lactate measurement and nucleated red blood cell (NRBC) counts when compared to base excess (BE) in the blood collected from the placental segment of the umbilical vein. METHODS: 25 umbilical cords from premature babies were sampled after placental delivery and cord clamping. Babies were followed until discharge. Statistics involved linear regression, Spearman's correlation, ROC curves, and Fisher's exact test. RESULTS: The relationship between lactate in the umbilical vein blood and pH and BE was significant (p < 0.0001). A 4.04 mmol/L lactate level showed a sensitivity of 62.5% and a specificity of 94.1% in detecting pH <7.2 and BE < -10 mmol/L. NRBC counts were related to BE (p = 0.0095), but with a sensitivity of 37.5% and specificity of 82.4% in detecting BE < -10 mmol/L. CONCLUSIONS: Lactate is a valuable marker of fetal hypoxia when sampled from placental segment veins. NRBC counts demonstrated low sensitivity for the detection of acidosis.

Keywords

• Lactato
• eritroblastos
• prematuro
• sofrimento fetal
• Lactate
• erythroblasts
• premature babies
• fetal distress