Ungerer J P, Ungerer M J, Vermaak W J
Department of Chemical Pathology, Faculty of Medicine, University of Pretoria, South Africa.
Clin Chem. 1990 Dec;36(12):2093-6.
Recent studies on the agreement and correlation between measured and calculated total CO2 (TCO2) have yielded conflicting results. Pre-analytical variation could have been partially responsible. While keeping such variables at an absolute minimum, we found excellent correlation (r = 0.98) in 88 samples, with only a small variation in agreement between measured and calculated TCO2 values (SD = 1.1 mmol/L), which could be a function of variation in apparent pK (pK'). A subsequent evaluation of 913 consecutive samples, routinely analyzed, yielded similar results. These results suggest that some of the discrepancies reported in the literature could be ascribable to differences in sample types and sample handling. Rigid control of pre-analytical procedures is therefore a prerequisite in studies on this topic. The two methods were found to agree over a wide range of values, such that either of them could be used to evaluate clinical acid-base status accurately.
近期关于实测总二氧化碳（TCO2）与计算所得总二氧化碳之间的一致性和相关性研究得出了相互矛盾的结果。分析前的差异可能是部分原因所在。在将此类变量保持在绝对最小值的情况下，我们在88个样本中发现了极佳的相关性（r = 0.98），实测和计算所得TCO2值之间的一致性仅有微小差异（标准差 = 1.1 mmol/L），这可能是表观pK（pK'）变化的一个函数。随后对913个连续常规分析样本的评估得出了类似结果。这些结果表明，文献中报道的一些差异可能归因于样本类型和样本处理的不同。因此，严格控制分析前程序是该主题研究的一个先决条件。发现这两种方法在很宽的值范围内具有一致性，以至于它们中的任何一种都可用于准确评估临床酸碱状态。
