Nephrology: Renal Tubular Acidosic

Question 1

Type 1

Answer 1

• distal RTA (body is acidotic, urine is basic)
• can’t secrete the H+ , urine become basic
• sickle cell, drugs, others
• when urine is basic, you get stones and nephrocalcinosis (in parenchyma of kidney)
  dx: give acid, normal person will excrete it, hypokalemia
  tx: give oral bicarb and potassium replacement

you can absorb base just fine (proximal tubule)

Question 2

Type 2

Answer 2

• proximal RTA (body is acidotic, urine is basic)
• proximal tube absorbs base
• fanconi, wilson dz, amyloidosis, myeloma, acetazolamide, vit D deficiency w/secondary hyperparathyroidism and chronic hypocalcemia, heavy metals, chronic hepatitis, autoimmune dz
• proximal unable to absorb bicarb
• urine is basic for awhile, until all the bicarb runs out of the body, then urine becomes acidic (no calcinosis, no stones)
• dx: give bicarb (normal person would absorb bicarb if they are acidosis)
• tx: give a thiazide diuretic to decrease the volume of the body (can’t give enough bicarb to fill the whole body)

Question 3

Type 4

Answer 3

• only one that has high potassium
• all the things that decrease aldosterone (aldosterone deficiency or adrenal insensitivity to angiotensin II, diabetes, addison dz, sickle cell, renal insufficiency)
• usually diabetic, hypo renin, hypoaldosterone
• give aldosterone (fludrocortisone closest thing)

Question 4

How kidney retains acid balance

Answer 4

excrete acid or absorb base

normally in distal tubule you excrete hydrogen ions - bind with ammonia to become ammonium and bind with phosphate to become phosphatic acid

• being acidotic sucks calcium out of bones

Question 5

RTA in general

Answer 5

• all have normal anion gap metabolic acidosis because all have elevated chloride
• diarrheas is the other normal anion gap metabolic acidosis
• urine anion gap can tell you the difference in these two