nephrolithiasis Flashcards
70% of all stones are..
calcium oxalate
dehydration is the most common cause of what two stone compositions
calcium oxalate
uric acid
- forms in wide range pH
- radio-opaque
- not dissolvable
calcium oxalate
- forms in acidic urine & dissolves w/ urinary alkalinization
- radiolucent
uric acid stones
- etio: metabolic conditions
- forms in alkaline urine
- radio-opaque
calcium phosphate
- etio: UTI
- forms in alkaline urine
- radio-opaque
- dissolves w/ urinary acidification
magnesium ammonium phosphate
- etio: cystinuria (hereditary); forms starting in childhood
- forms in acidic urine; radio-opaque
- disolves with alkalinization
cysteine stones
- colic/wave like, sharp flank pain (may radiate to abdomen, testicles/labia)
- hematuria; N/V; LUTS or asymp. (usually non-obstructing)
nephrolithiasis (kidney stones)
obstructing ones usually cause sx secondary to hydronephrosis
intermittent obstruction–> colic
- fluid in kidneys d/t obstruction anywhere along tract
- silent or sx
- can d/t stone, strictures, BOO, BPH, extraureteral compression, trauma, edema, UPJ, clot, reflux
hydronephrosis
hydroureteronephrosis?
imaging: IVP (IV pyelogram), KUB, non- con CT flank, etc
tx of nephrolithiasis
- sx control
- surveillance- small nonobstructing renal calculi
- dissolution tx- uric acid stone -> urinary alkalinization
- medical expulsive therapy
- surgical intervention– large ureteral or bladder calculi, refractory small/medium, large non-obstructing
what is medical expulsive therapy
- trial of spontanoeous passage where you try hydration, pain control + alpha blocker or steroids
- good if its a passable stones, good pain control, no infection, appropriate renal function
what surgical procedure is this
- gel pad under lower body & fluoroscopy
- US waves to break up stone +/- stenting
- C/I: pregnancy, coagulopathy, UTI, renal artery calcifications, AAA, radiolucent stones
- complications: hematoma, ecchymosis, UTI, pain, steinstrasse, lower stone clearance rate
ESWL– extracorporal shockwave lithotripsy
- option for stone basketing; good for failed ESWL or non-ESWL candidate
- cystolitholapaxy
- complications: ureteral perforation, stricture
- rigid version for ureteral distal stones
- felxible for failed ESWL, < 2 cm, complex anatomy, proximal stones
ureteroscopy w/ laser lithotripsy
- removes renal calculi from kidney through percutaneous access from back into kidney
- small hole for large stones
- disadv: 2-3 day admission, stent or nephrostomy tube
- uses: large stones over 2.5 cm, failed ESWL, complex anatomy, staghorn stones
- complications: infxn, pneumo/hemothorax, injury, extravastation of urine, bowel injury
PCNL– percutaneous nephrolithotomy
5 indications for emergent tx
- obstructing stone + infection
- bilateral
- one kidney
- refractory pain
- cannot tolerate oral intake d/t N/V
goal is to drain system via stent & run or nephrostomy tube
5 indications for emergent tx
- obstructing stone + infection
- bilateral
- one kidney
- refractory pain
- cannot tolerate oral intake d/t N/V
goal is to drain system via stent & run or nephrostomy tube
why is it super important to prevent stones
if you have it once theres a high chance it will happen again– $$, pain, etc
what 4 group of foods should be avoided to help prevent stones
high oxalate foods- rhubarb, spinach, tofu, nuts, beans, beets, potatoes/ yams
high sodium
excess fleshy foods
high purines or caclium intake
how are calcium stones managed? (4)
- tx hypercalcemia– thiazide diuretics
- tx hypocitraturia w/ potassium citrate
- tx hyperuricosuria w/ allopurinol
- tx cystinuria w/ thiola
4 metabolite abnormality seen in urine with calcium stones
hypercalcemia, hyperuricosuria
hypocitraturia
cystinuria
medication? what should you monitor for? treats what?
- decreases urinary Ca & corrects acidoses by increasing its reabsorption in proximal & distal tubules
- inhibits sodium reabsorption in distal tubule
thiazides– hypercalciuria
monitor for HYPOkalemia
medication? what should you monitor for? treats what?
- urinary alkalinizer that increases urinay citrate w/ goal pH over 6.5
potassium citrate- treats hypocitraturia
monitor for HYPERkalemia (sodium bicarb, baking soda)
medication? treats what?
decreases urinary uric acid and works even if normal serum uric acid
allopurinol- treats hyperuricemia
medication? treats what?
forms bond w/ cysteine to increase its urine solubility
thiola– treats cystinuria
