BACKGROUND Total hemoglobin (tHb) measurement is indispensable for determining the patient's condition (hemorrhagic vs. ischemic) and need for blood transfusion. Conductivity- and absorbance-based measurement methods are used for blood gas analysis of tHb. For conductivity-based measurement, tHb is calculated after converting blood conductivity into a hematocrit value, whereas absorbance measurement is based on light absorbance after red blood cell hemolysis. Due to changes in plasma electrolytes and hemolysis, there is a possibility that conductivity- and absorbance-based measurement methods may cause a difference in tHb. METHODS In this study, test samples with controlled electrolyte changes and hemolysis were created by adding sodium chloride, distilled water or hemolytic blood to blood samples collected from healthy volunteers, and tHb values were compared between both methods. RESULTS Conductivity-based measurement revealed reduced tHb value (from 15.49 to 13.05 g/dl) following the addition of 10% sodium chloride, which was also reduced by the addition of hemolysate. Conversely, the addition of distilled water significantly increased tHb value than the expected value. In the absorbance method, there was no significant change in tHb value due to electrolyte change or hemolysis. CONCLUSIONS We have to recognize unexpected conductivity changes occur at all times when tHb is measured via conductivity- and absorbance-based measurement methods. The absorbance method should be used when measuring tHb in patients with expected blood conductivity changes. However, when using this method, the added contribution of hemoglobin from hemolytic erythrocytes lacking oxygen carrying capacity must be considered. We recognize that discrepancy can occur between conductivity- and absorbance-based measurement methods when tHb is measured.

中文翻译：

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测量原理对总血红蛋白值的影响。

背景技术总血红蛋白（tHb）测量对于确定患者的状况（出血性与缺血性）和输血需求必不可少。基于电导率和吸收率的测量方法用于tHb的血气分析。对于基于电导率的测量，tHb是在将血液电导率转换为血细胞比容值之后计算的，而吸光度测量则是基于红细胞溶血后的光吸收率。由于血浆电解质的变化和溶血，基于电导率和吸收率的测量方法可能会导致tHb的差异。方法在本研究中，通过向健康志愿者收集的血液样本中添加氯化钠，蒸馏水或溶血血液，制成具有受控电解质变化和溶血的测试样本，比较两种方法的tHb值。结果基于电导率的测量显示，添加10％氯化钠后，tHb值降低（从15.49 g / dl降低至13.05 g / dl），添加溶血产物也降低了tHb值。相反，添加蒸馏水会使tHb值明显高于预期值。在吸收法中，由于电解质的变化或溶血，tHb值没有显着变化。结论我们必须认识到，通过基于电导率和吸光度的测量方法测量tHb时，电导率始终会发生意外变化。在预期血液电导率变化的患者中测量tHb时应使用吸收法。但是，使用这种方法时，必须考虑缺乏氧气携带能力的溶血性红细胞对血红蛋白的额外贡献。我们认识到，在测量tHb时，基于电导率和基于吸收率的测量方法之间可能会出现差异。