CUA MEDICAL MANAGEMENT OF Kidney stone patient 2016 Flashcards
limited Evaluation for first time stone-formers?
UA + Culture, serum lytes, Serum Ca, Serum creatinine
Who should have in depth metabolic evaluation?
- Any patient with stone interested and willing
- children<18
- bilateral or multiple stones
- Recurrent stones ( 2 or more episodes)
- Non-calcium stones
- pure calcium phosphate stones
- any complicated stone episode that resulted in a severe( if even temporary acute kidney injury, spesis, hospitalization, complicated hospital admission)
- any stone requiring PCNL (due to infectious nature of Struvite, metaabolci evaluation is not needed in this group)
- Stones in the setting of solitary kidney
- patients with renal insufficiency
- history of kidney stones and systemic disease that increases the risk of kidney stones( gout, osteoprosis, bowel disorders, hyper PTH, renal tubular acidosis,
- occupation where public safety at risk( pilots, Air traffic controllers, military personnel
is routine metabolci evaluation recommended for struvite stones?
Nope
C+ S + imaging
What serum tests does in depth metabolic evluation entail?
- Cr, Na, K, Cl, Ca, Alb, Uric acid, bicarb
- PTH if Ca high normal or abnormaly elevated
- Vit D if low normal serum Ca or elevated serum PTH
What 24 hour urine tests does in depth metabolic evluation entail?
Volume, Cr, Ca, Na, K, Oxalate, Citrate, UA, Mg, Cystine( if suspecting cystine stone)
What do you learn from spot urine when doing stone work up? (in depth)
Urine pH
UA
Specific gravity
How many 24 hour urines?
two,
but be practical and at least obtain one
Should you send stones for analysis?
In short yes
if patient passes ask them to keep and if you remove them send them
Should you repeat stone analysis if patient has recurrent stones?
yes,
22% of patients stone composition changes overtime
What is the “stone clinic effect”?
counselling on appropriate fluid intake to avoid dehydration and dietary excesses can significantly reduce stone recidivism
Does making specific dietary recommendations by a dietician matter
Yes, shown to reduce recurrences
What is the recommended fluid intake and output for prevention of recurrences?
2.5-3 L intake for a UO of 2.5 L ( shown to reduce stone risk by 61%)
Is restriction of coffee, tea and alcohol recommended
no, some studies show they help, some dont, but dont need to rstrict as long as they are drinking enough water
What is the dietary calcium intake goal
1000-1200 in diet
How should calcium supplementation be given?
Should be taken at mealtimes, conflicting evidence re Cacarb vs ca-citrate
Is nephrolithiasis associated with increased risk of fractures?
Yes, particularly if Vit D deficient
HR of 1.55
Is vitamin D recommended for stone formers?
In CaOX stone formers with documented vitD deficiency, repletion is appropriate but should monitor 24 hour urine for hypercalciuria
Which has the highest purine content FIsh chicken or beef
Fish, causes inc UA excretion
Should animal protein intake be restricted
in patients with recurrent CaOx and UA stones, moderation of animal prtoein intake and avoidance of purien rich foods suggested.
What is a low sodium diet associated with?
With Low urinary Na, lower urinary Ca
decreased risk of stones
recommendation re Na intake?
Patients with recurrent Ca Nephrolithiasis should aim for Na intake of 1500mg/day and no more than 2300mg/ day
recommendations re fruits and vegetables?
For kidney stone patient diet high in fiber, fruits, vegetables may offer a small protective effect against stone formation.
Is vitamin C supplementation recommended?
NO! Vit C is thought to become oxalate. Vit C of more than 1000 mg daily is not recommended due to the associated risk of hyperoxaluria and nephrolithiasis
Name three thiazides
HCTZ, chlorthalidone, indapamide
What are Serum and urine changes associated with thiazides
Serum: hypokalemia, hyperglycemia, hyperlipidemia, hyperuricemia, hypomagesemia
Urine: hypocitraturia, decreased urine ca
mix it with K citrate or KCL to fight hypokalemia and prevent hypocholeremic metabolci acidosis
Recommendations re thiazides
thiazides been shown to decrease urinary ca and rate of stone recurrence in Ca
Name 3 alkali citrates
K-citrate, K-mg-citrate, Na-citrate
What do alkali citrate do?
Effective in increasing urinary citrate, urinary pH, and reducing stone recurrence in Ca stone formers
Side effects of allopurinol
Rash, stomach upset, abnormal liver enzymes, prolonged elimination in renal disease
Which ca stone former is allopurinol helpful for?
Calcium oxalate stones with hyperuricosuria and normocalciuria.
Name 4 conditions that can lead to pure CaPH stones?
primary hyper PTH distal RTA chronic UTI hypercalciuria hyperphosphaturia
How do you treat patients with dRTA?
with K-citrate. shown to be better than other citrates. will cause increased urine pH, inc urine citrate, dec urine calcium,
What are features of dRTA?
urine ph>5.8, hypocitraturia,
serum: dec bicarb, dec K,
pure appatitie stones
what are features of primary hyper-PTH?
Serum: high or high N serum Ca, high or high N serum PTH,
Urine: hypercalcuria
decreased bone mineral density
caOx or CaPH stones
Underlying metabolic disorder associated with Uric acid stones?
obesity, metabolci syndrome, diabetes mellitus, excessive bicarb loss due to high output bowel disease, Myeloproliferative disorders, tumor lysis syndrome.
What are most important factors for uric acid stone formation
low urine pH and volume not hyperuricosuria
what is primary treatment for uric acid stone formers?
alkalinize urine to goal ph of 6.5,
allopurinol may be used as an adjunct in cases of hyperuricemia or hyperuricosuria
What is the goal UO in cystinurics?
3L
what dietary recommendations for cystinurics?
restric sodium and animal protein intake
Whats the goal urine pH in cystinurics?
7 to 7.5
What are side effects of penicillamine?
fever, arthalgias, rash, dysgeusia, leuopenia, protienuria
Does captapirl work?
not clear, not currently recommended
how can you monitor effectiveness of thiol treatment as second line therapy in cystinurics?
monitor urinary supersaturiation of cystine or cystine capacity
What is a medical therapy that prevents struvite stones?
urease inhibitor acetohydroxamic acid
has significant side effects
What are FU recommendations?
repeat metabolic testing in 6 months and then yearly if prophylaxis is given.
periodic imaging
