Pighi Laura, Salvagno Gian Luca, Marcazzan Filippo, Rizza Mariateresa, Lippi Giuseppe
Section of Clinical Biochemistry, University of Verona, Verona, Italy.
J Med Biochem. 2025 Jul 4;44(4):915-918. doi: 10.5937/jomb0-58604.
Hemolysis is the most frequent preanalytical error in clinical laboratories, but its detection in point-of-care (POC) settings remains challenging due to the lack of sample separation. This study was planned to validate the hemolysis index (HI) threshold of GEM Premier 7000 blood gas analyzer for detecting hemolysis levels that may generate clinically significant interference in potassium measurement.
Heparinized whole blood samples were collected from healthy volunteers and divided into six aliquots; one was used as non-hemolyzed control, while hemolysis was mechanically induced in the remaining five aliquots by repeated aspirations through a fine-gauge needle. HI and potassium were measured on GEM Premier 7000.
The final study population consisted of 18 volunteers. Both HI and potassium levels increased progressively and significantly with the number of fine-needle aspirations (p<0.001 for both). A strong positive correlation was observed between HI values and percentage increases in potassium concentration in hemolyzed aliquots (r=0.985, p<0.001). Receiver operating characteristic (ROC) curve analysis confirmed excellent diagnostic accuracy of HI in detecting potassium increases above the minimum total 7.4% allowable error threshold, with an area under the curve (AUC) of 1.00 and optimal cutoff of 102 mg/dL (0.94 sensitivity and 1.00 specificity). At the manufacturer-recommended 116 mg/dL threshold, the AUC was 0.95, with 0.89 sensitivity and 1.00 specificity.
These results confirm that the novel GEM Premier 7000 blood gas analyzer provides accurate detection of hemolysis thresholds in whole blood that may impair potassium test reliability.
溶血是临床实验室中最常见的分析前误差，但由于缺乏样本分离，在即时检验（POC）环境中对其进行检测仍具有挑战性。本研究旨在验证GEM Premier 7000血气分析仪的溶血指数（HI）阈值，以检测可能对钾测量产生临床显著干扰的溶血水平。
从健康志愿者采集肝素化全血样本并分成六份；一份用作未溶血对照，其余五份通过细针反复抽吸机械诱导溶血。在GEM Premier 7000上测量HI和钾。
最终研究人群包括18名志愿者。HI和钾水平均随着细针抽吸次数的增加而逐渐显著升高（两者p均<0.001）。在溶血样本中，观察到HI值与钾浓度升高百分比之间存在强正相关（r = 0.985，p<0.001）。受试者工作特征（ROC）曲线分析证实，HI在检测高于总允许误差阈值最低7.4%的钾升高方面具有出色的诊断准确性，曲线下面积（AUC）为1.00，最佳截断值为102 mg/dL（灵敏度为0.94，特异性为1.00）。在制造商推荐的116 mg/dL阈值下，AUC为0.95，灵敏度为0.89，特异性为1.00。
这些结果证实，新型GEM Premier 7000血气分析仪能够准确检测全血中可能损害钾检测可靠性的溶血阈值。
