Acid-base homeostasis is one of the most tightly regulated systems in the body. Maintaining the acid-base balance is particularly challenging for preterm infants and growing neonates. The kidney, which represents the crucial ultimate line of defense against disturbances of acid-base balance, undergoes a complex maturation process during the transition from a fetal to an extra-uterine environment. This review article summarizes the physiology of acid-base regulation by the immature human kidney and discusses disorders of acid-base balance, such as metabolic acidosis, respiratory acidosis, metabolic alkalosis, and respiratory alkalosis. In conditions of metabolic acidosis, the serum anion gap and the urinary anion gap can be useful tools to define the nature of the acidosis. Metabolic acidosis can reflect a decrease in glomerular filtration rate, or be the consequence of selective disorders of proximal or distal tubular function. Most tubulopathies associated with metabolic acidosis observed in neonates are primary, hereditary, isolated tubulopathies. Proximal renal tubular acidosis is characterized by bicarbonate wasting, while the distal types of renal tubular acidosis are secondary to distal acidification defects. All tubulopathies are associated with hypokalemia, with the exception of type 4 hyperkalemic distal renal tubular acidosis. The transporter defects in the various acid-base tubulopathies are now well defined. Treatment of the acidosis varies according to the site and mechanism of the defect. Chronic renal tubular acidosis or alkalosis severely impair growth and calcium metabolism. Early rational therapeutic intervention can prevent some of the consequences of the disorders and improves the prognosis.

中文翻译：

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新生儿代谢性酸碱紊乱的肾脏方面。

酸碱稳态是人体中调节最严格的系统之一。对于早产儿和成长中的婴儿，维持酸碱平衡尤其具有挑战性。肾脏代表了抵抗酸碱平衡紊乱的关键最终防御线，在从胎儿到宫外环境的过渡过程中，它经历了复杂的成熟过程。这篇综述文章总结了未成熟的人类肾脏对酸碱调节的生理学，并讨论了酸碱平衡失调，例如代谢性酸中毒，呼吸性酸中毒，代谢性碱中毒和呼吸性碱中毒。在代谢性酸中毒的情况下，血清阴离子间隙和尿液阴离子间隙可能是定义酸中毒性质的有用工具。代谢性酸中毒可反映肾小球滤过率降低，或者是近端或远端肾小管功能选择性疾病的结果。在新生儿中观察到的大多数与代谢性酸中毒有关的肾小管病变是原发性，遗传性，孤立性肾小管病变。近端肾小管性酸中毒的特征在于碳酸氢盐的浪费，而远端肾小管性酸中毒的类型继发于远端酸化缺陷。除4型高钾性远端肾小管酸中毒外，所有肾小管病变均与低钾血症有关。现在已经很好地定义了各种酸碱性肾小管病变中的转运蛋白缺陷。酸中毒的治疗根据缺损的部位和机制而异。慢性肾小管酸中毒或碱中毒严重损害生长和钙代谢。