Schambelan M, Sebastian A
Nephrologie. 1985;6(3):135-7.
Type IV renal tubular acidosis (RTA) is a syndrome of tubular dysfunction manifested clinically by persisting hyperkalemia and metabolic acidosis that occurs usually in patients with mild to moderate chronic glomerular insufficiency. The pathophysiologic characteristics include: reduced renal clearance of potassium; a reduced rate of renal bicarbonate reabsorption at normal plasma bicarbonate concentrations (the magnitude of which is insufficiently great to implicate the proximal tubule); an unimpaired ability to maintain a steep hydrogen ion concentration gradient between blood and urine during acidosis; and a reduced rate of renal net acid excretion despite highly acidic urine, due in part to reduced urinary excretion of ammonium, which in turn appears to be due in part to suppression of renal ammoniagenesis by hyperkalemia. Many patients with type IV RTA, but not all, have hyporeninemic hypoaldosteronism. The roles of mineralocorticoid deficiency and hyperkalemia in the pathogenesis of type IV RTA will be considered and the ameliorative effects of treatment with fludrocortisone, furosemide, and dietary potassium restriction reviewed.
IV型肾小管酸中毒（RTA）是一种肾小管功能障碍综合征，临床上表现为持续性高钾血症和代谢性酸中毒，通常发生于轻至中度慢性肾小球功能不全患者。其病理生理特征包括：肾脏排钾减少；在正常血浆碳酸氢盐浓度下，肾脏重吸收碳酸氢盐的速率降低（其幅度不足以提示近端小管受累）；在酸中毒期间，血液与尿液之间维持陡峭氢离子浓度梯度的能力未受损；尽管尿液高度酸性，但肾脏净酸排泄速率降低，部分原因是铵的尿排泄减少，而这又似乎部分归因于高钾血症对肾脏氨生成的抑制。许多IV型RTA患者（但并非全部）存在低肾素性低醛固酮血症。将探讨盐皮质激素缺乏和高钾血症在IV型RTA发病机制中的作用，并综述氟氢可的松、呋塞米治疗及饮食限钾的改善效果。
