Nephrolithiasis Flashcards
dietary factors that lead to nephrolithiasis
low fluid intake, calcium, K
high oxalate, protein, Na, sugar drinks
Inhibitors of stone formation
magnesium, citrate, pyrophosphate, THprotein
inhibits caox crystal formation and growth binding with oxalate
Magnesium
retards the crystal growth of CaP and CaOx crystals by binding to the surface of basic CaP crystals
pyrophosphate
chelates calcium, reduced calcium binding calcium with Ox and P
Citrate
acts as both promoter and inhibitor of stone formation
THProtein
metabolic processes that induce ca stone formation
Increase urine ca > 4 mkd, 250-300 mg/day; Urine Uric acid > 800 mg/day, urine oxalate > 45 mg/d, Dec Ucitratee < 320 mg/day; alterations in urine ph
most common metabolic abnormality in ca stone formation
absorptive hypercalciuria
most common cause of resoprtive hypercalciuria
primary hyperparathyroidism
highest source of uric acid
de novo synthesis
clinical conditions with hypocitraturia
overproduction acidosis, underexcretion acidosis
K deficiency
excess dietary protein
autosomal recessive condition in childhood with CaOx stones and nephrocalcinosis, frequent stone recurrence
primary hyperoxaluria
inflammatory bowel disease, jejunoileal bypass, bariatric surgery for morbid obesity
enteric hyperoxaluria
predispose to hyperuricosuric ca oxalate lithiasis
highly acidic urine (pH < 5.5)
predispose to caphos lithiasis
alkaline urine (pH > 6.7)
most impt in uric acid stones
low urine pH
main cause of idiopathic uric acid urolithiasis
low urine pH
patients with gouty arthritis and kidney stones, UA > 10 md/d, urine ua > 1000 mg/day
hyperuricosuria
Increases saturation of all stone forming elements
low urine volume
Pathophysio of uric acid stones
Low urine pH, volume
Hyperuricosuria
genetic disease caused by inactivating mutations of the subunits of a dibasic aminoacid transporter in then proximal tubule
cystinuria
most common primary inherited aminoaciduria
cystinuria
family hx of cystinuria (> 400 mg/day vs 30 mg), staghorn calculi, hexagonal crystals on urinalysis
cystinuria
most prevalent component of kidney stones
calcium oxalate
most likely cause of nephrolithiasis in a patient with distal RTA
hypocitraturia
depressions near the papillary tips, yellow crystalline deposits in the ducts of bellini, some randall plaques
Calcium phosphate