Wang Li, Albert Arianne Y K, Jung Benjamin, Hadad Keyvan, Lyon Martha E, Basso Melanie
BC Children's & Women's Hospital, University of British Columbia, 4500 Oak Street, Room 2J9, Vancouver, BC, V6H 3 N1, Canada.
BC Children's Hospital Research Institute, University of British Columbia, Vancouver, BC, Canada.
BMC Pediatr. 2017 Mar 29;17(1):92. doi: 10.1186/s12887-017-0842-8.
Neonatal hyperbilirubinemia has traditionally been screened by either total serum bilirubin or transcutaneous bilirubin. Whole blood bilirubin (TwB) by the GEM Premier 4000® blood gas analyzer (GEM) is a relatively new technology and it provides fast bilirubin results with a small sample volume and can measure co-oximetry and other analytes. Our clinical study was to evaluate the reliability of TwB measured by the GEM and identify analytical and clinical factors that may contribute to possible bias.
440 consecutive healthy newborn samples that had plasma bilirubin ordered for neonatal hyperbilirubinemia screening were included. TwB was first measured using the GEM, after which the remainder of the blood was spun and plasma neonatal bilirubin was measured using the VITROS 5600® (VITROS).
62 samples (14%) were excluded from analysis due to failure in obtaining GEM results. Passing-Bablok regression suggested that the GEM results were negatively biased at low concentrations of bilirubin and positively biased at higher concentrations relative to the VITROS results (y = 1.43x-61.13). Bland-Altman plots showed an overall negative bias of the GEM bilirubin with a wide range of differences compared to VITROS. Both hemoglobin concentration and hemolysis affected the accuracy of the GEM results. Clinically, male infants had higher mean bilirubin levels, and infants delivered by caesarean section had lower hemoglobin levels. When comparing the number of results below the 40th percentile and above the 95th percentile cut-offs in the Bhutani nomogram which would trigger discharge or treatment, GEM bilirubin exhibited poor sensitivity and poor specificity in contrast to VITROS bilirubin.
An imperfect correlation was observed between whole blood bilirubin measured on the GEM4000® and plasma bilirubin on the VITROS 5600®. The contributors to the observed differences between the two instruments were specimen hemolysis and the accuracy of hemoglobin measurements, the latter of which affects the calculation of plasma-equivalent bilirubin. Additionally, the lack of standardization of total bilirubin calibration particularly in newborn specimens, may also account for some of the disagreement in results.
传统上，新生儿高胆红素血症通过血清总胆红素或经皮胆红素进行筛查。GEM Premier 4000®血气分析仪（GEM）检测的全血胆红素（TwB）是一项相对较新的技术，它能以少量样本快速得出胆红素结果，并且可以测量血氧定量法及其他分析物。我们的临床研究旨在评估GEM检测TwB的可靠性，并确定可能导致偏差的分析和临床因素。
纳入440例因新生儿高胆红素血症筛查而送检血浆胆红素的连续健康新生儿样本。首先使用GEM测量TwB，之后将剩余血液离心，使用VITROS 5600®（VITROS）测量血浆新生儿胆红素。
62份样本（14%）因未能获得GEM结果而被排除在分析之外。Passing-Bablok回归分析表明，相对于VITROS结果，GEM结果在低胆红素浓度时呈负偏差，在高胆红素浓度时呈正偏差（y = 1.43x - 61.13）。Bland-Altman图显示，与VITROS相比，GEM胆红素总体呈负偏差，差异范围较广。血红蛋白浓度和溶血均影响GEM结果的准确性。临床上，男婴的平均胆红素水平较高，剖宫产分娩的婴儿血红蛋白水平较低。在比较Bhutani列线图中低于第40百分位数和高于第95百分位数临界值（这将触发出院或治疗）的结果数量时，与VITROS胆红素相比，GEM胆红素的敏感性和特异性较差。
在GEM4000®上测量的全血胆红素与VITROS 5600®上的血浆胆红素之间观察到不完全相关性。两种仪器之间观察到的差异的影响因素包括样本溶血和血红蛋白测量的准确性，后者会影响血浆等效胆红素的计算。此外,总胆红素校准缺乏标准化，尤其是在新生儿样本中，这也可能是结果存在一些差异的原因。
