Correction of factitious hyperkalemia in hemolyzed specimens
Correction of factitious hyperkalemia in hemolyzed specimens
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DOI：
10.1016/j.ajem.2005.05.011
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发表时间：
2005-11-01
影响因子：
3.6
通讯作者：
Hampers, LC
中科院分区：
文献类型：
--
作者：
Owens, H;Siparsky, G;Hampers, LC
背景：由于抽血困难和小口径静脉导管，溶血在儿科标本中很常见。血清K+值继发于细胞内内容物的释放而虚升高。如果存在一个可靠的校正因子，可以避免重复的K+测量。目的：本研究的目的是利用游离血浆血红蛋白（p-Hgb） a，一种体外溶血的测量方法，建立人为升高K+的校正因子。方法：用23号针采集健康成人全血20份，分为4组：(1)不加操作，(2)27号针机械溶血，(3)加醋酸钾（KAc），(4)加醋酸钾并机械溶血。添加KAc以模拟潜在的显著高钾血症。所有标本均进行了标准K+和p-Hgb测量。结果：未溶血和溶血K+分别为3.2 ~ 8.1 mEq/L和3.5 ~ 10.0 mEq/L。从未溶血到溶血，K+和p-Hgb的变化呈线性关系。K+的校正因子为0.00319（95%置信区间为0.00290-0.00349）× p-Hgb。结论：在临床相关范围内存在可靠的人为高钾血症校正因子。例如，使用上述校正因子，一个电话预测，δ K+在500 mg/dL的p-Hgb样品将为1.6 mEq/L（范围，1.5-1.7）。我们建议，当预测的δ K+的下界结果在参考范围内的修正值，第二次抽血是不必要的。(c) 2005爱思唯尔公司版权所有。
Background: Hemolysis in pediatric specimens is common due to difficult blood draws and small-bore intravenous catheters. Values of serum K+ become falsely elevated secondary to release of intracellular contents. If a reliable correction factor existed for this factitious elevation, repeat K+ measurements might be avoided.Objective: The aim of the Study was to establish a correction factor for factitiously elevated K+, using free plasma hemoglobin (p-Hgb) a, a measure of in vitro hemolysis.Methods: Twenty whole-blood specimens drawn from healthy adults via a 23-gauge needle were divided into 4 aliquots: (1) no manipulation, (2) mechanical hemolysis via a 27-gauge needle, (3) addition of potassium acetate (KAc), and (4) addition of KAc and mechanical hemolysis. KAc was added to mimic potentially significant hyperkalemia. All specimens had standard K+ and p-Hgb measurements performed.Results: Nonhemolyzed and hemolyzed K+ ranged from 3.2 to 8.1 mEq/L and 3.5 to 10.0 mEq/L, respectively. A linear relationship existed between the change in K+ and p-Hgb from the nonhemolyzed to hemolyzed specimens. A correction factor for K+ of 0.00319 (95% confidence interval, 0.00290-0.00349) X p-Hgb was obtained.Conclusions: A reliable correction factor for factitious hyperkalemia in a clinically relevant range exists. By example, using the above correction factor, one call predict that the delta K+ in a specimen with 500 mg/dL of p-Hgb will be 1.6 mEq/L (range, 1.5-1.7). We suggest that when the lower bound of the predicted delta K+ results in a corrected value within the reference range, a second blood draw is unnecessary. (c) 2005 Elsevier Inc. All rights reserved.