Renal Tubular Acidosis Flashcards
What acid/base disorder is associated with all forms of renal tubular acidoses?
normal anion gap metabolic acidosis w/ hyperchloremia
What is the defect in Type 1?
alpha intercalated cells of the collecting duct cannot secrete H+. –> metabolic acidosis.
Is K+ high or low in Type 1?
hypokalemia.
What kind of kidney stones may form with RTA type one?
Calcium phosphate (increased urine pH), increased bone turnover.
What are the causes of RTA 1?
amphotericin B, analgesics, congenital obstruction of urinary tract
urine pH in RTA 1?
ph > 5.5
What is the defect in RTA type 2?
Defect in PCT bicarb reabsorption. Increased bicarb excretion in urine and subsequent metabolic acidosis.
Is K+ high or low in Type 2?
hypokalemia.
What disease is there an increased for with type 2?
hypophosphatemic rickets.
what is the urine pH in RTA 2?
What are causes of RTA 2?
Fanconi syndrome and carbonic anhydrase inhibitors.
What is the defect in RTA type 4?
Hypoaldosteronism.
Why does decreased aldosterone create acidosis?
Aldo normally upregs Enac channels and brings in more Na+, leading to greater excretion of potassium…without it, there is hyperkalemia–> potassium inhibits NH3 synth in the PCT, so hyperkalemia causes decreased NH3 synthesis in PCT –> decreased NH4 excretion. W/ decreased NH4 secretion, more H+ is reabsorbed.
What are some causes of decreased aldosterone production?
diabetic hyporeninism, ACEis/ARBs, NSAIDs, heparin, cyclosporine, adrenal insufficiency
What are some causes aldosterone resistance?
K+ sparing diuretics (spironolactone etc), nephropathy due to obstruction, TMP-SMX
