Chan J C
Adv Pediatr. 1983;30:401-71.
In the normal human body, the extracellular fluid pH of 7.40 is closely protected. Any increase in acidity or alkalinity summons forth three lines of defense, starting immediately with the blood buffers, followed soon by the respiratory system's control of CO2, and finally purged by the renal excretion of the excess acid or base. The complex interrelated processes of the renal responses require a few days to accomplish maximum compensation. We have presented the fundamental principles governing maintenance of the acid-base equilibrium to provide a conceptual framework for understanding the clinical disorders of hydrogen ion metabolism. The somewhat elusive concepts of endogenous acid production and net acid balance have also been reviewed to help reveal the pathophysiology of metabolic acidosis caused by renal tubular acidosis, chronic renal failure, certain infant feedings, and total parenteral nutrition. The development and perpetuation of metabolic alkalosis in relationship to chloride and potassium deficiency have been examined. In the delineation of a clinical acid-base disorder, the clinician must bear in mind the continual interactions of electrolytes and hormonal systems and should be prepared to reevaluate frequently the elected therapy against the changing responses, based on a thorough understanding of physiology. The various types of renal tubular acidosis have manifold facets but the basic understanding of their pathophysiology begins with the concept of the "anion gap," a point of reference that can be used in the differential diagnosis and treatment. In this chapter a number of new causes of type IV renal tubular acidosis--currently considered to be the most common form of renal tubular acidosis--have been pointed out, along with special reference to the mineral, electrolyte, and aldosterone metabolism in the various acidoses and current means of reversing growth failure in the child, especially through bicarbonate treatment. The mechanism of metabolic acidosis in chronic renal failure including metabolic acidosis in children undergoing dialysis and in recipients of kidney transplantation, and its relationships to mineral and electrolyte metabolism have been presented. The pathophysiology of the acidosis related to certain infant formulas and the acidogenic properties of some amino acid solutions employed in total parenteral nutrition have been briefly reviewed. Finally, the metabolic alkalosis seen in a variety of chloride deficiency syndromes, such as Bartter's syndrome and dietary chloride deprivation, has been discussed and a rational approach to evaluation and treatment outlined.
在正常人体中，细胞外液pH值7.40受到严密保护。酸度或碱度的任何增加都会引发三道防线，首先是血液缓冲系统立即发挥作用，接着是呼吸系统对二氧化碳的调控，最后通过肾脏排泄多余的酸或碱来消除影响。肾脏反应的复杂相互关联过程需要几天时间才能实现最大程度的代偿。我们阐述了维持酸碱平衡的基本原理，以提供一个理解氢离子代谢临床紊乱的概念框架。还回顾了内源性酸产生和净酸平衡这些有些难以捉摸的概念，以帮助揭示由肾小管酸中毒、慢性肾衰竭、某些婴儿喂养方式以及全胃肠外营养引起的代谢性酸中毒的病理生理学。研究了与氯和钾缺乏相关的代谢性碱中毒的发展和持续情况。在诊断临床酸碱紊乱时，临床医生必须牢记电解质和激素系统的持续相互作用，并应基于对生理学的透彻理解，随时准备根据不断变化的反应重新评估所选的治疗方法。各种类型的肾小管酸中毒有多个方面，但对其病理生理学的基本理解始于“阴离子间隙”的概念，这是一个可用于鉴别诊断和治疗的参考点。在本章中，指出了IV型肾小管酸中毒（目前被认为是最常见的肾小管酸中毒形式）的一些新病因，特别提及了各种酸中毒中的矿物质、电解质和醛固酮代谢，以及目前逆转儿童生长发育迟缓的方法，尤其是通过碳酸氢盐治疗。阐述了慢性肾衰竭中代谢性酸中毒的机制，包括接受透析的儿童和肾移植受者的代谢性酸中毒，以及它与矿物质和电解质代谢的关系。简要回顾了与某些婴儿配方奶粉相关的酸中毒的病理生理学以及全胃肠外营养中使用的一些氨基酸溶液的产酸特性。最后，讨论了在各种氯缺乏综合征（如巴特综合征和饮食性氯缺乏）中出现的代谢性碱中毒，并概述了评估和治疗的合理方法。
