新生儿小时胆红素百分位曲线图的制备及早期预测高胆红素血症的初步探讨

Early prediction of hyperbilirubinemia by neonatal hour-specific bilirubin nomogram

目的绘制新生儿胆红素百分位曲线图预测新生儿高胆红素血症的发生风险。方法选择2009年1~9月南京医科大学附属南京妇幼保健院出生的母婴同室和普通婴儿室胎龄≥35周且出生体重≥2 000 g的正常新生儿为研究对象,监测生后7 d经皮胆红素值（TCB）,对TCB≥250μmol.L-1者测定微量血胆红素,以所得到的胆红素值数据绘制小时胆红素百分位曲线图。以小时胆红素百分位曲线图将出院前末次胆红素值转换至危险区域（低危：≤P40;中低危：~P75;中高危：~P95;高危：〉P95）。选取72 h内对应最高危区域的胆红素测定值作为预测指标,采用ROC曲线分析胆红素百分位曲线图对新生儿高胆红素血症的预测价值。结果4 462例新生儿的27 271个对应不同小时龄的胆红素值纳入分析。出院前有5.2%（233/4 462例）的新生儿在生后72 h内的胆红素水平处于高危区,其中48.9%（114/233例）的新生儿在出院后胆红素水平仍处于高危区,预测新生儿发生高胆红素血症的似然比为9.5,敏感度为26.7%,特异度为97.1%,患病率为48.9%;出院前共有23.2%（1 034/4 462例）的新生儿胆红素水平处于高危区和中高危区,预测新生儿发生高胆红素血症的敏感度为78.9%,特异度为82.5%;出院前有41.3%（1 845/4 462例）的新生儿胆红素水平处于低危区,其中无一例在出院后发生高胆红素血症,似然比为0,敏感度为100%,特异度为45.5%,患病率为0。出院前胆红素水平预测高胆红素血症发生风险的ROC曲线下面积（AUC）为0.870。胎龄与出院前胆红素水平相结合预测高胆红素血症发生风险的ROCAUC为0.908。结论用出院前小时胆红素水平预测新生儿高胆红素血症的发生风险是一种有效的方法,结合胎龄可提高预测的准确性。

Objective To design the hour-specific bilirubin nomogram of healthy term and near-term newborns and assess its predictive ability to screen risks of sequent hyperbilirubinemia.Methods Transcutaneous bilirubin（TCB） was measured for healthy infants（gestational age≥35 weeks and birth weight≥2 000 g） from birth to 7 days.Infants whose TCB≥250 μmol·L-1 were detected for bilirubin with microdetermination.We designed the hour-specific bilirubin nomogram with these data.Newborns were divided into 4 groups based on the predischarge bilirubin ＂risk zone＂（≤40th,-75th,-95th,and 95th percentile defined as low,low-intermediate,high-intermediate and high risk zones on the hour-specific bilirubin nomogram） to predict subsequent hyperbilirubinemia.Results Four thousand and four hundred sixty-two infants with 27 271 hour-specific bilirubin data were enrolled into the study.Before discharge,total serum bilirubin（TSB） values of 5.2%（233/4 462） infants were in the high-risk zone;of them,48.9%（114/233） remained in that zone [likelihood ratio（LR） 9.5,sensitivity 26.7%;specificity 97.1%,probability 48.9%] post discharge.Before discharge,TSB values of 23.2%（1 034/4 462） infants were in the high-risk and intermediate-risk zone（sensitivity 78.9%,specificity 82.5%）.The predischarge TSB values in 41.3%（1 845/4 462） infants were in the low-risk zone and there was no measurable risk for hyperbilirubinemia（LR 0,sensitivity 100%,specificity 45.5%,probability 0）.The receiver operating characteristic（ROC） curves were drawn to assess the predictive abilities of the predischarge bilirubin level and prediction model that was combined with gestational age.The areas under the ROC curves were 0.870 and 0.908,respectively.Conclusions The study showed good predictivity of hour-specific TSB to the risk of hyperbilirubinemia of newborns.Gestational age improved prediction of subsequent hyperbilirubinemia compared with early TSB levels alone.