Diagnosis of metabolic acid-base disturbances in critically ill patients
Diagnosis of metabolic acid-base disturbances in critically ill patients
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DOI：
10.1164/ajrccm.162.6.9904099
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发表时间：
2000-12-01
影响因子：
24.7
通讯作者：
Figge, J
中科院分区：
文献类型：
--
作者：
Fencl, V;Jabor, A;Figge, J
我们比较了两种常用的诊断方法，一种依赖于血浆碳酸氢盐浓度和“阴离子间隙”，另一种依赖于“碱过量”，第三种方法基于物理化学原理，其价值在检测复杂的代谢性酸碱失衡。我们分析了152名患者和9名正常受试者的动脉血样本的pH值、Pco（2）以及血浆电解质和蛋白质浓度。96%的患者血清白蛋白浓度低于或等于对照组平均值3 SD。在大约六分之一的患者中，碱过剩和血浆碳酸氢盐正常。在绝大多数这些明显正常的样品中，第三种方法检测到同时存在酸化和碱化干扰，其中许多是严重的。当应用常规方法时，几乎普遍存在的低白蛋白血症混淆了酸碱数据的解释。碱过量在大约六分之一的患者中遗漏了严重的酸碱异常;当非碳酸氢盐缓冲液（主要是白蛋白）的血浆浓度异常时，这种方法失败了。阴离子间隙检测到一个隐藏的“间隙酸中毒”，只有31%的正常血浆碳酸氢盐，其中这种酸中毒是由第三种方法诊断的样本;当调整低白蛋白血症，它可靠地检测到隐藏的异常阴离子。提出的第三种方法确定和量化复杂的酸碱异常的各个组成部分，并提供其发病机制的见解。
We compare two commonly used diagnostic approaches, one relying on plasma bicarbonate concentration and "anion gap," the other on "base excess," with a third method based on physicochemical principles, for their value in detecting complex metabolic acid-base disturbances. We analyzed arterial blood samples from 152 patients and nine normal subjects for pH, Pco(2), and concentrations of plasma electrolytes and proteins. Ninety-six percent of the patients had serum albumin concentration less than or equal to 3 SD below the mean of the control subjects. In about one-sixth of the patients, base excess and plasma bicarbonate were normal. In a great majority of these apparently normal samples, the third method detected simultaneous presence of acidifying and alkalinizing disturbances, many of them grave. The almost ubiquitous hypoalbuminemia confounded the interpretation of acid-base data when the customary approaches were applied. Base excess missed serious acid-base abnormalities in about one-sixth of the patients; this method fails when the plasma concentrations of the nonbicarbonate buffers (mainly albumin) are abnormal. Anion gap detected a hidden "gap acidosis" in only 31% of those samples with normal plasma bicarbonate in which such acidosis was diagnosed by the third method; when adjusted for hypoalbuminemia, it reliably detected the hidden abnormal anions. The proposed third method identifies and quantifies individual components of complex acid-base abnormalities and provides insights in their pathogenesis.