Qavi Abraham J, Franks Caroline E, Grajales-Reyes Gary, Anderson Jeanne, Ashby Lori, Zohner Kimberly, Gronowski Ann M, Farnsworth Christopher W
Department of Pathology & Immunology, Washington University, School of Medicine, St. Louis, MO, United States.
National Institutes of Health, Bethesda, MD, United States.
Clin Biochem. 2023 May;115:137-143. doi: 10.1016/j.clinbiochem.2022.03.008. Epub 2022 Mar 26.
Quantity not sufficient (QNS) specimens with minimal blood volume for testing are common in clinical laboratories. However, there is no universal definition of minimum volume for a QNS specimen and little data is available addressing the impact of QNS / low volume specimens on turnaround time (TAT) and sample hemolysis. We compared the TAT and hemolysis index from samples ≤1.0 mL to all specimens received and quantified the number of specimens with reduced blood volume. A new QNS policy requiring ≥1.5 mL of sample in a blood tube for laboratory analysis was implemented and the results were assessed by sample hemolysis and TAT. The median laboratory TAT for samples with ≤1.0 mL of blood was 61 min (Interquartile Range, IQR: 50-82), in contrast to 28 min (26-34) for all samples. The hemolysis index for samples ≤1.0 mL was 112 (65-253) and 15 (8-29) for all samples. Requirement of a minimum volume of 1.5 mL of blood resulted in the proportion of samples with TAT ≥ 60 min to decrease from 10.4% to 4.24% in the ED, and for specimens cancelled due to hemolysis to decrease from 4.24% to 3.38%. This policy was introduced hospital wide with similar effects. Together, we correlate limited specimen volume with an increase in laboratory TAT and hemolysis. Implementation of a QNS policy of ≥1.5 mL and provider education provided a significant and durable reduction in TAT and specimen hemolysis.
临床实验室中,血量不足以进行检测的“量不足(QNS)”标本很常见。然而,对于QNS标本的最小血量尚无统一的定义,而且关于QNS/低血量标本对周转时间(TAT)和样本溶血影响的数据也很少。我们将血量≤1.0 mL的样本的TAT和溶血指数与所有接收的标本进行了比较,并对血量减少的标本数量进行了量化。实施了一项新的QNS政策,要求血样管中的样本量≥1.5 mL才能进行实验室分析,并通过样本溶血和TAT对结果进行评估。血量≤1.0 mL的样本在实验室的中位TAT为61分钟(四分位间距,IQR:50-82),而所有样本的中位TAT为28分钟(26-34)。血量≤1.0 mL的样本的溶血指数为112(65-253),而所有样本的溶血指数为15(8-29)。要求最小血量为1.5 mL使得急诊室中TAT≥60分钟的样本比例从10.4%降至4.24%,因溶血而取消的标本比例从4.24%降至3.38%。该政策在全院推行后效果类似。我们发现标本量有限与实验室TAT增加和溶血相关。实施≥1.5 mL的QNS政策并对医护人员进行教育,可显著且持久地缩短TAT并减少标本溶血。