So once we've diagnosed our patient and
we've done our basic and complete evaluation,
there's some things that we can keep in
mind for general medical management.
This includes dietary modification
and lifestyle modification - this is critical.
We want our patients to increase their fluid intake
to produce at least 2 to 2 1/2 liters of urine per day.
We want them to have a low
sodium diet less than 2300 mg per day.
The reason being is that high
sodium will actually worsen calciuria.
We want a low to moderate animal protein intake
and we also want them to have reduced sugar drinks.
Again, having high sugary drinks actually
precipitates calciuria - that means calcium in the urine.
We also want to ensure that they have adequate
calcium intake that's age appropriate in the diet.
Why is this?
because lowering dietary calcium without lowering dietary
oxalate particularly in somebody who's making calcium oxalate
can precipitate stone formation due to
less intestinal binding of ingested oxalate.
We also want to reduce dietary oxalate if
that patient again has a calcium oxalate stone.
So couple of things for us to think about in
specific populations for specific stone types.
We have calcium stones, uric acid
stones, struvite stones and cysteine stones.
Let's start with calcium stones.
Calcium stones make up about 70% of
all stones, we had talked about that before.
Most are composed of calcium oxalate or
in combination with phosphate or uric acid.
The risk factors for stone formation include hypercalciuria
- remember that means too much calcium in the urine,
or excessive 1,25-D levels.
That's that active form of vitamin D also called calcitriol.
Hyperoxaluria, that could be due to dietary
intake remember those foods like tea, chocolate
could be because of GI malabsorption or inherited
enzyme deficiencies that cause primary hyperoxaluria.
Hypocitrituria is also a risk factor for stone formation.
Remember citrate is a chelator, it will chelate calcium.
Without the presence of that in the
urine, that can lead to hypercalciuria.
And then finally, hyperuricosuria.
So about 10 to 15% of calcium
stones are as in association with this
and this has to do with nucleation of
calcium oxalate around that uric acid crystal.
So, again other treatments, if the patient has a
calcium-based stone, how do we want to treat them?
We want to do the general treatment
that we've already talked about,
right, that's the behavioral and
dietary modification but in addition
there's a couple of other things
that we can do to help our patients.
We can use a thiazide diuretic if they have hypercalciuria,
that works specifically to reduce urine calcium.
We can also have them reduce dietary
oxalate if they have a calcium oxalate stone
so either treating that underlying disorder if they
have GI malabsorption or primary hyperoxaluria as well.
We can give them potassium citrate.
This is going to increase citrate
availability and raise the urinary pH
which can help with the
solubility of calcium oxalate stones.
Remember, these guys are gonna
precipitate in an acidic environment.
So if we can increase that pH and create a more
alkaline pH, then that that stone will be more soluble
and in addition, remember what citrate does,
it's a chelator so it will help to chelate calcium.
And remember allopurinol, if patients
have an increase in uric acid excretion,
we can use that to reduce uric acid
production when they have a combination stones.