study guide questions

Question 1

similarities & diffs in management of Ca2+ oxalate & uric acid kidney stones

Answer 1

Ca2+ =

1) increase fluid intake
2) reduce urinary Ca
3) reduce urinary oxalate
4) increase natural inhibitors of crystal formation-citrate, Mg

Uric acid = DITTO + low purine diet && maintain alkaline urine (>6pH)

Question 2

what type of fluids should be emphasized and which reduced?

Answer 2

good = black tea, coffee, milk, beer, wine

bad= grapefruit, apple, cranberry juice, soft drinks

Question 3

explain how using certain quantitative urine tests can help guide Dr in managing kidney stones

Answer 3

24-h urine analysis = ddx: abortive hypercalciuria = should still take calcium

Question 4

how can Ca supplements be made safer for patients with a Hx of kidney stones?

Answer 4

• -supplementation = should be taken with a meal so it can bind to the dietary oxalate
• -citrate forms of Ca &/or Mg may increase benefits

Question 5

what is the role of Mg, Vit B6, Vit C in the formation of kidney stones?

Answer 5

• -Mg = low = more stones
• -Vit B6 = increase oxalate formation from normal body metabolism, reduce stone formation
• -Vit C = increase urinary oxalate. not sure if high dosing actually helps. Pt should be tested w/ 24-h urinary oxalate while high dosing Vit C