强离子差：酸碱帝王的新范式还是新衣裳。

Department of Critical Care Medicine, Flinders Medical Centre, Adelaide, SA

Crit Care Resusc. 1999 Jun;1(2):214.

OBJECTIVE

To review and compare the 'metabolic' component of an acid-base abnormality by assessing the arterial blood bicarbonate and the 'strong ion difference'.

DATA SOURCES

A review of published peer-review articles and studies reported from 1983 to 1999 and identified through a MEDLINE search on 'strong ion difference'.

SUMMARY OF REVIEW

The Henderson-Hasselbalch equation describes the simple relationship between the arterial pH, PaCO(2) and bicarbonate concentration (HCO(3)(-)), and has been used by clinicians to classify acid-base abnormalities as either respiratory or a non-respiratory (i.e. metabolic). However, as the HCO(3)(-) concentration cannot be measured directly and as it can also be altered by an alteration in the PaCO(2), derived values such as the standard bicarbonate, buffer base, base excess and standard base excess have been proposed to assess the true 'metabolic' acid-base component. Recently, an analysis of acid-base has been reported based on the Law of electroneutrality in aqueous solutions, in which it is proposed that the independent variables of 'strong ions' (e.g. sodium, potassium, calcium, magnesium, chloride and organic anions), CO(2) and non volatile weak acids (i.e. A(TOT)) alter the dependent variables of pH and HCO(3)(-). The concept of 'strong ion difference' (SID) is used to help explain 'metabolic' acid base abnormalities, particularly those associated with saline infusions. The relationship between the HCO(3)(-) ion and the SID can be represented as HCO(3)(-) = (SID - A(-)) and the Henderson Hasselbalch equation can be written as pH infinity (SID - A(.))/PaCO(2) although, the body regulates pH by regulating the PaCO(2) and HCO(3)(-), rather than by regulating the SID or A(TOT).

CONCLUSIONS

In man the renal and respiratory systems regulate acid-base homeostasis by modifying the bicarbonate buffer pair (i.e. PCO(2) and HCO(3)(-)), with all other body buffer systems adjusting to alterations in this pair. To maintain electrical neutrality there is a change in cation concentration commensurate with the change in bicarbonate concentration.

目的

通过评估动脉血碳酸氢盐和“强离子差”来回顾和比较酸碱失衡的“代谢”成分。

资料来源

对 1983 年至 1999 年发表的同行评议文章和研究进行了回顾，并通过 MEDLINE 对“强离子差”进行了搜索。

综述摘要

亨德森-哈塞尔巴尔赫方程描述了动脉 pH 值、PaCO2 和碳酸氢盐浓度（HCO3-）之间的简单关系，临床医生已将其用于将酸碱失衡分类为呼吸性或非呼吸性（即代谢性）。然而，由于 HCO3-浓度不能直接测量，并且由于 PaCO2 的改变也会改变 HCO3-浓度，因此已经提出了标准碳酸氢盐、缓冲碱、碱剩余和标准碱剩余等衍生值来评估真正的“代谢”酸碱成分。最近，据报道，根据水溶液中的电中性定律对酸碱进行了分析，该定律提出，“强离子”（如钠、钾、钙、镁、氯和有机阴离子）、CO2 和非挥发性弱酸（即 A(TOT)）的独立变量会改变 pH 和 HCO3-的依赖变量。“强离子差”（SID）的概念用于帮助解释“代谢性”酸碱失衡，特别是那些与盐水输注相关的酸碱失衡。HCO3-离子与 SID 之间的关系可以表示为 HCO3- = （SID - A-），并且可以将亨德森-哈塞尔巴尔赫方程表示为 pH 无穷大（SID - A(.))/PaCO2，尽管身体通过调节 PaCO2 和 HCO3-来调节 pH 值，而不是通过调节 SID 或 A(TOT)。