Renal Tubular Acidosis Flashcards
cause of proximal RTA (type 2)
- tubular defect in HCO3 reabsorption
serum K+ levels in proximal RTA
- mild hypokalemia due to hyperaldosteronism
proximal RTA associated with what other lab effects
what is the combination of these effects called?
- aminoaciduria
- glycosura
- uricosura
- phosphaturia
- fanconi syndrome
pH of urine in proximal RTA
- < 5.5
conditions that cause proximal RTA
- drugs
- autoimmune disease
- congenital anomalies
clinical manifestation of proximal RTA
- weakness
- bone pain and fractures
- impaired growth
why bone pain and fractures in RTA
- decreased synthesis of active vit D
- phosphate wasting
distal (type 1) RTA cause
- alpha intercalated cells can’t secrete H+ into urine
serum potassium in distal RTA
why
- hypokalemia
- decreased H+ secretion makes CCD more negative
- K+ flows in
conditions that cause distal RTA
- falconi
- sjorgren
- hypercalcuria
- mutations in H+ ATPase and carbonic anhydrase
- drugs
clinical manifestations of distal RTA
- weakness
- impaired growth in children
- calcium phosphate stones
- chronic kidney disease
pH of urine in distal RTA
> 5.5
type 4 RTA cause
result
- defect in aldosterone secretion or activity
- hyperkalemia
- decreased ENaC activity
- suppressed ammoniagenesis
what suppresses ammoniagenesis in type 4 RTA
result
- hyperkalemia
- leads to the acidosis
urine pH in type 4 RTA
why
- <5.5
- lack of buffering by NH3
conditions that cause type 4 RTA
- low renin
- high renin
- aldosterone resistance
what can cause low renin in type 4 RTA
- diabetes
- HIV
- aging
- NSAIDS
result of high renin in type 4 RTA
- decreased aldosterone stimulation
what can cause high renin in type 4 RTA
- ACE inhibitors
- ARBs
- adrenal injury
what can cause aldosterone resistance in type 4 RTA
- spironolactone
- epleronone
- abnormal mineralocorticoid receptor
cause of voltage dependent hyperkalemic RTA
- defect in ENaC activity
- decreased Na delivery to CCD
urine pH of voltage dependent hyperkalemic RTA
why?
> 6
- high lumen positive charge so can’t excrete H+
conditions that cause voltage dependent hyperkalemic RTA
- severe hypovolemia
- urinary tract obstruction
- sickle cell disease
- ENaC blockage
what can block ENaC
- amiloride
- triamterene
- trimethoprim
- pentamidine
APTT
all pussy tastes terrible. ENaC is the sound you make.
what toxicity mimics RTA
- toluene toxicity
