Reevaluation of the Harboe Assay as a Standardized Method of Assessment for the Hemolytic Performance of Ventricular Assist Devices
Reevaluation of the Harboe Assay as a Standardized Method of Assessment for the Hemolytic Performance of Ventricular Assist Devices
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DOI：
10.1111/j.1525-1594.2012.01515.x
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发表时间：
2012-08-01
影响因子：
2.4
通讯作者：
Hawkins, Karl
中科院分区：
文献类型：
--
作者：
Chan, Chris H. H.;Hilton, Andrew;Hawkins, Karl
Harboe 分光光度法被认为是测量血浆游离血红蛋白 (pfHb) 的最安全、最具重复性的方法之一。然而，在评估心室辅助装置（VAD）的溶血性能时，该测定的应用仍然存在一些模糊性。本研究的目的是重新检查和比较各种研究引用的使用不同浓度的血浆稀释剂 (Na2CO3) 获得的 pfHb 值，以便推荐在 VAD 溶血评估中应用 Harboe 测定的标准做法，从而在实验室之间进行可靠的比较。作为检查 Harboe 测定的一种方法，使用全血和洗涤后的红细胞 (RBC) 悬浮液对 BioMedicus BPX-80 进行了测试。结果表明，对于全血，pfHb 可能被低估 1323%，具体取决于 Na2CO3 稀释溶液的浓度。对于洗涤的红细胞悬浮液没有观察到这种趋势。此外，表明稀释剂的浓度影响样品的稳定性。这项研究的结果表明，与 pfHb 读数不一致相关的问题是碱性条件下血浆中蛋白质沉淀的直接结果；由于稀释剂的摩尔浓度控制 pH 值，因此必须使用适当浓度的 Na2CO3 稀释剂，以避免溶液浑浊以及由此导致的 pfHb 值的误报。当测量现代心室辅助装置体内测试期间观察到的极低水平的 pfHb 时，这种标准化是相关的。
The Harboe spectrophotometric assay is regarded as one of the safest and most reproducible methods for measuring plasma free hemoglobin (pfHb). However, there is still some ambiguity in the application of the assay when assessing the hemolytic performance of ventricular assist devices (VADs). The purpose of this study was to reexamine and compare values of pfHb obtained using different concentrations of plasma diluent (Na2CO3) as cited by various studies such that a standard practice may be recommended for the application of the Harboe assay in the hemolytic evaluation of VADs, allowing reliable comparisons to be made between laboratories. As a means to examine the Harboe assay, a BioMedicus BPX-80 was tested using both whole blood and a washed suspension of red blood cells (RBCs). Results show that for whole blood, the pfHb may be underestimated by 1323%, dependent upon the concentration of Na2CO3 diluent solution. This trend was not observed for the washed suspension of RBCs. Furthermore, it is shown that the concentration of diluent influences the stability of a sample. The results of this study show that the problems associated with the incongruity of pfHb readings are a direct result of the precipitation of proteins from the plasma under alkaline conditions; as the molarity of the diluent controls pH, it becomes essential to use the appropriate concentration of Na2CO3 diluent in order to avoid turbidity of the solution and the consequent misrepresentation of pfHb values. Such standardization is pertinent when measuring the very low levels of pfHb observed during the in vivo testing of modern ventricular assist devices.