Services de Biochimie, Laboratoire de Biologie Médicale Multi-Sites, Hôpitaux Est-Sud-Nord-Edouard Herriot, Hospices Civils de Lyon (HCL), Lyon, France.
Services de Biochimie, Laboratoire de Biologie Médicale Multi-Sites, Hôpitaux Est-Sud-Nord-Edouard Herriot, Hospices Civils de Lyon (HCL), Lyon, France.
Clin Biochem. 2019 May;67:40-47. doi: 10.1016/j.clinbiochem.2019.02.014. Epub 2019 Mar 2.
Reference intervals for arterial and venous umbilical cord blood gas (UCBG) parameters are scarce, are mainly focused on pH, pO2, pCO2 and base deficit, and are usually assessed using parametric tests, despite a generally skewed data distribution. Here, the purpose is to determine reference percentiles for nine parameters of concomitant arterial and venous UCBG (CAV-UCBG) from neonates at birth, using nonparametric tests.
Results of CAV-UCBG, assayed over a 4.5-year period, were extracted from a hospital laboratory database for pH, pCO2, pO2, oxygen saturation, concentration of total oxygen, total carbon dioxide, hydrogen carbonate, total haemoglobin, and acid-base excess. Exclusion criteria were: a venous-arterial pH difference <0.02, an arterial-venous pCO2 <0.7 kPa, and a venous pCO2 <2.9 kPa. Nonparametric bivariate kernel density estimations were used for the selection of plots within the 95% percentile surface of the pCO2-to-pH relationship (NBKDE-95P). Outliers from skewed data were removed using an adjusted-Tukey method, and percentiles were calculated according to the CLSI EP28-A3 nonparametric method.
Overall, 31% (5033/16164) of CAV-UCBG were discarded using the three exclusion criteria. Then, 6% (670/11131) of CAV-UCBG were excluded from the NBKDE-95P, and 0.1 to 3.5% outliers were subsequently removed. Depending on the parameter, the 2.5th and 97.5th percentiles from the whole group were similar or slightly narrower compared to reference intervals from other studies, while those from female and male neonates did not differ substantially.
Using an indirect nonparametric approach, this study proposes new percentiles for parameters from concomitant arterial and venous umbilical cord blood gases.
脐带血气（UCBG）参数的参考区间较为匮乏，主要集中在 pH 值、pO2、pCO2 和碱剩余，且通常使用参数检验进行评估，尽管数据分布通常呈偏态。本研究旨在使用非参数检验确定出生时脐动静脉血气（CAV-UCBG）九个参数的参考百分位数。
从医院实验室数据库中提取了 4.5 年间 CAV-UCBG 的结果，分析了 pH 值、pCO2、pO2、氧饱和度、总氧浓度、总二氧化碳浓度、碳酸氢盐、总血红蛋白和酸碱平衡。排除标准为：静脉-动脉 pH 值差值<0.02、动脉-静脉 pCO2<0.7kPa 和静脉 pCO2<2.9kPa。使用非参数双变量核密度估计法（NBKDE-95P）选择 pCO2-pH 关系的 95%百分位曲面内的图。使用调整后的 Tukey 方法去除偏态数据中的离群值，并根据 CLSI EP28-A3 非参数方法计算百分位数。
总体而言，使用三种排除标准排除了 31%（5033/16164）的 CAV-UCBG。然后，从 NBKDE-95P 中排除了 6%（670/11131）的 CAV-UCBG，随后去除了 0.1%至 3.5%的离群值。根据参数的不同，与其他研究的参考区间相比，整个组的第 2.5 和 97.5 百分位数相似或略窄，而女性和男性新生儿的百分位数则没有显著差异。
使用间接非参数方法，本研究提出了新的脐动静脉血气参数的百分位数。
