Renal Tubular Disorders and Renal Tubular Acidosis Flashcards
Classic Bartter syndrome general and patho
Hypokalameia, hypochrloremia, and met alklalosis
Increased urinary excretion of K and PGs
Low normal BP despite increased renin and aldosterone levels
hyperplasia of JG apparatus (increased renin secretion)
Mutation in CLC-Kb….increased systemi cPG syntehsis secondary to decreased entery of Na and Cl into the MD, hypokalameia, volume ocntraction and increased AT2
Classic barter syndrome clinically
Onset during 1st few years, milder than neonatal
Polyuria and polydipsia
Vomiting
Dehydration
Constipiation
Failure to thirve
Carpopedal spasms and developmental delay
Neonatal bartter syndrome
Auto rec
Defective NKCC2, ROMK or ClC-Kb
Polyhydramnios
Premature birth
Vomiting
Polyuria
Fialure to thirve
HYPERclaciuria…lack of apircal potassium to maintain gradient for transtubular calcium absrption
Similar to loop dirutetic
Dx of classic and neonatal bartter syndrme
Hypokalmeia with met alkalosiis …high renin and aldosterone in classic but can be low with severe hypokalmeia
High urinary PGE2 and Cl levels
Tx - correction fo fluid and electrolye abnormalities
KCl supps
K sparing iduretics
ACE inhibitors
PG synthase inhibitors (decrease cortical perfusion and decrease delivery fo NaCL to distal neprhon)
Gitelman
Auto rec
Hypokalmeic metabolic lkalosis with hypocalcuria and hypomagnesemia
Mutation in NCCCT in the DCT
NaCl wasting leads to hypovolemia with RAAS activation
Increased collecting tubule Na reabsorption leads to H and K secretion with hypokalmeic acidosis
No hypercalciuria since NaCl reabsorption is not driving force for Ca reabsorption in DCT
Impairtment of sodium reentry lowers IC sodium concentration…facilitates Na-Ca echange across basolateral membrane
Gitelman dx and tx
Unexplained and mild hypokalemia
Normal BP
Often asx
Weakness and tetany
Hypomagnesemia, hypermagnesuria and hypocalcuria
Mild increase in RAAS
Normal urine PGs
Tx - MgCl supps, K suppes, PG syns inhibitors
Prognosis is excellent
Mutations affecting the epithelial sodium channels
Rate limiting barrier for entry of sodium into the cell…results in negative transepithelial voltage leading to potassium secetion into lumen and hydrogen ion from intercalated
MCs normally bind and activat ethis
Liddle’s syndrome
Auto dom with early penetrance
Severe HTN with hypoklameia and met alklaosois
No real renal dysfuntion
Mutation encoding for epithalil sodium channel…persistent unregulated reabsorption of sodium and increased secretion of potassium and H ions in the collecting tubule
Dx of LIddles
Strong fam hx of CNS and CV dz
Mostly in teens and YA
Polyuria, increased thirst, Sig HTN
Hypokalemic met alkalosis
LOW RAAS
Dx is often undiagnosed
Tx to LIddle
Triamterene - directly inhibits apical Na channels leading to decreased Na reabsorption and decreased postassium excretion
Amiloride
Salt rest
Other antiHTN meds
NOT spironolacotne
Nephrogenic DI
Cannot concentrate urine in ocllecting duct
X-linked V2 receptor mutation
Auto rec AQP-2 gene mutation
Sodium level rises becasue def in free water
NDI
Hypernatremic dehydration in infants…especially in fromula fed
Dilute urine
Normal to low BP…No A-B abnormalities
Irritability, poor feeding, poor wiehgt gain
Dehydration - sunken anterior fontanelle, scaphoid abdomen, loss of turgor, fever
NDI dx
Water deprivation test
If serum sdoium rises, weight decreases and urine output/osmolality to not change, give desmopressin
If no response, confirmed dx
Tx of NDI
Dietary mods to minimize olute loads
Low sodium and protein diet without inducing malnutrtion
HCTZ to drecrease urine output
PG synthesis inhibitors to induce pre-renal physiology
Affected nephron segments
Bartters
Gitelmans
Liddles
NDI
TALH
Distal tubule
Cortical collecting duct
Collecting duct
