Term
| what is the etiology for renal/ureteric stones? |
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Definition
| usually unknown: all stone formers should be evaluated for hormonal/diet/other physiologic problems |
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Term
| who gets urolithic stones more: M or F? |
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Definition
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Term
| what is the composition of 75% of all urolithic stones? |
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Definition
| *calcium oxalate w/calcium phosphate being the next most common. generally, urinary stones are polycrystalline aggregates composed of crystalloid and organic matrix. |
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Term
| t/f: advances in surgical treatment have outpaced our understanding of etiology of stone formation? |
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Definition
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Term
| how high is the recurrence rate for urolithic stones? how can this be lowered? |
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Definition
| recurrence rate: up to 50% w/in 5 yrs - this can be lowered w/lifestyle changes. |
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Term
| what does stone formation require? |
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Definition
| supersaturated urine (emphasize importance of oral fluids) |
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Term
| what is necessary in determining therapy for stone formation? |
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Definition
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Term
| what is the major ion present in urolithic stones? how much is excreted normally in urine? |
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Definition
| Ca - which < 2% is excreted normally in urine (check 24 urine and serum for Ca) |
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Term
| where does the oxalate come from found in urolithic stones? |
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Definition
| 10-15% from diet, the rest: bi-product from metabolism |
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Term
| what characterizes phosphate as a urolithic stone component? |
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Definition
| phosphate is an important buffer, and complexes with Ca in the second-most common form of urolithic stones |
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Term
| what characterizes uric acid as a component of urolithic stones? |
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Definition
| uric acid is a bi-product of purine metabolism and is insoluble in acidic pH (important b/c it *may dissolve w/alkalinization of urine) and may contribute to hypersaturation of urine. |
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Term
| what characterizes citrate's role in urothlic disease? |
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Definition
| citrate should normally be in urine and is an important inhibitor of stone formation |
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Term
| what is a magnesium deficiency associated with? |
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Definition
| formation of calcium oxalate crystal formation |
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Term
| what role does sodium play in urolithic disease? |
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Definition
| Na+ encourages stone formation (regulates crystallization of Ca++ salts in urine) |
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Term
| what role does sulfate play in urolithic disease? |
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Definition
| sulfate may help prevent urinary calculi |
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Term
| what is absorptive hypercalciuric nephrolithiasis (AHN)? what type is the most common? |
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Definition
| when there is increased Ca+ absorption from the small bowel (mostly the jejunum). 3 types: type I (independent of diet), type II (*most common cause of urinary stone disease), and type II (secondary to phosphate leak) (absorptive refers specifically to the action of the jejunum) |
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Term
| what % of pts w/hyperparathyroidism present w/nephrolithiasis (resorptive hypercalciuric nephrolithiasis)? |
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Definition
| 50% (but hyperparathyroidism only accounts for 5-10% of stone disease pts). (resorptive refers specifically to the excess PTH causing the kidney to resorb excess Ca++) |
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Term
| what is the most consistent sign of hyperparathyroidism? tx? |
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Definition
| hypercalcemia. sx removal of the parathyroid adenoma is the only effective tx. |
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Term
| what are the noncalcium calculi? |
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Definition
| struvite, uric acid, cysteine, xanthine, and drug related |
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Term
| what are struvite calculi? |
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Definition
| struvite calculi are composed of magnesium/ammonium/phosphate and form *staghorn calculi (fill hollow part of the kidney). these are most common in *women and *rapidly form large stones. struvite stones are always associated w/an *infection (urea splitting organisms such as proteus/pseudomonas). these stones are associated with *alkaline urine (pH rarely below 7), and there is no way to sterilize the stone so it must be removed (antibx will only work on some of the bacteria, no blood supply to a stone). |
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Term
| what characterizes uric acid calculi? |
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Definition
| rare, more often seen in men. uric acid calculi do have high incidence in *gout, *myeloproliferative disease, and pts on *cytotoxic drugs. most pts do NOT have hyperuricemia, just *elevated urine uric acid. alkalinization of urine may *dissolve these calculi. uric acid stones are *radiolucent (but do show on CT scan) |
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Term
| what are cysteine and xanthine calculi usually due to? |
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Definition
| inborn errors of metabolism. they are radiolucent and more soluble in alkaline urine - like uric acid stones. |
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Term
| what characterizes the pain associated with uroliths? |
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Definition
| pain may be constant (distention of the renal capsule) or colicky (distention of collecting duct system) - either due to urine backing up as a result of obstruction. this pain is usually abrupt, severe, *not affected by movement*, and crescendo-like. |
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Term
| if a stone is near the ureteropelvic junction, where the ureter starts where will the pt experience pain? |
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Definition
| in the flank/upper quadrant |
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Term
| if a stone is farther down the ureter, where will the pt experience pain? |
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Definition
| pain will radiate lower down |
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Term
| if a stone is near/at the bladder, where will the pt experience pain? |
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Definition
| scrotum/inguinal/labial area |
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Term
| after a stone passes into the bladder, does pain continue? |
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Definition
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Term
| is hematuria present w/uroliths? |
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Definition
| yes, almost always - even if small |
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Term
| why does n/v often occur w/uroliths? |
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Definition
| innervation of the kidney and upper GI is shared |
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Term
| if there is fever associated w/a urolith, what does this constitute? |
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Definition
| a medical emergency, fever+obstruction = bacteriemia -> shock -> death |
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Term
| what should be in the ddx for urolithic disease? |
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Definition
| appendicitis, cholecystitis, diverticulitis, pancreatitis, ectopic pregnancy, ovarian pathology, bowel obstruction, peptic ulcer, and aortic aneurysms. (basically any inflammatory condition that can induce any inflammation in the peritoneum will present similarly, except lack of movement will reduce pain in any other pt than those w/uroliths) |
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Term
| what are risk factors for |
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Definition
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Term
| what are risk factors for stone disease? |
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Definition
| crystalluria, socioeconomic (more common in affluent pts), diet (increased fat/animal protein/sugar), occupation (physical activity will concentrate urine through fluid loss via sweat), climate (higher incidence in hot climate), fam hx, medications (triamterene, AIDs rx), large vit CA doses, and caffeine/tea |
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Term
| what are the imaging modalities used for stone disease evaluation? |
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Definition
| non-contrast CT (*first study done*), survey abdominal x-ray (KUB - only used if you don't want more radiation), ultrasound (not enough detail for initial study - won't show stone in ureter or smaller kidney stones, but good for f/u), and retrograde pyelography (only done if stone is not passed and hydronephrosis is progressing) |
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Term
| what is the rate of spontaneous passage for uroliths? how does size affect this? |
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Definition
| >80% will pass w/in 6 wks. <4 mm pass spontaneously, >6 mm will not (will chronically block and destroy a kidney). |
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Term
| can alpha sympathetic blocking agents help w/passage of a kidney stone? |
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Definition
| yes, drugs such as tamsulosin will dilate the smooth muscle in the ureter |
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Term
| how is pain control applied in the context of stone disease? |
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Definition
| pain control needs to be the first step, starting w/parenteral narcotics in-pt and NSAIDs out-pt |
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Term
| do stone disease pts need to force oral fluids? |
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Definition
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Term
| if stone disease pts have n/v should they be hospitalized? |
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Definition
| yes - for IV fluids/parental rx |
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Term
| why does all urine need to be strained until pts pass their stone(s)? |
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Definition
| to know that it has passed and for analysis |
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Term
| t/f: fever w/uroliths = medical emergency? |
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Definition
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Term
| when might a ureteral stent or nephrostomy tube be used in a stone disease pt? |
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Definition
| if the pt is too sick/febrile, if obstruction is too much, if the infection needs to be immediately controlled. |
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Term
| what oral prep can be used for uric acid stones? |
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Definition
| sodium or potassium bicarb - will alkalinize urine and dissolve uric acid stones |
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Term
| what is extracorporeal shock wave lithotripsy (ESWL)? |
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Definition
| focused shock waves are directed at stones to break them up, usually used on renal stones 1-2 cm (< 3cm) and ureteric calculi. |
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Term
| what does ureteroscopic stone extraction consist of? |
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Definition
| this can reach all the way up to the kidney w/a scope from the bladder. the goal here is to make fragments less than a few mm, so they pass spontaneously |
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Term
| what should be done when pts are out of the acute phase once passing their stone? |
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Definition
| stone analysis. 24 hr urine (check: volume, Ca, P, uric acid, citrate, oxalate, pH) and serum (Ca, P, uric acid, BUN, creatinine). if hypercalciuric: check PTH level. |
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Term
| why is urinary tract calculi prevention so important? |
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Definition
| w/o prevention, 50% of pts will have recurrence |
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Term
| what does urinary tract calculi prevention consist of? |
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Definition
| ID/modify risk factors, double fluid intake over 24 hr period (increase fluids 2 hrs after meal & "drink enough that your urine is clear" - *most important*), alkalinizing agents such as *potassium citrate/lemon juice* can reduce urinary saturation of calcium oxalate (also effective against uric acid lithiasis), reduction of Na+ intake, *thiazide diuretics (HCTZ) can lower Ca++ levels, uric acid lowering meds (*allopurinol for hyperuricosuric and uric acid stone formers), GI absorption inhibitors (cellulose phosphate for absorptive hypercalciuria type I), and phosphate supplementation (for renal phosphate leak - Al, Mg, Ca) |
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Term
| what characterizes incidence of bladder stones? |
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Definition
| bladder stones today are uncommon and are usually associated with underlying pathology: BPH, stricture, voiding dysfunction, or foreign body. they are seen mostly in males, usually solitary, associated w/infection, and produce: irritative symptoms (frequency, urgency, dysuria, hematuria), voiding symptoms, and hematuria. |
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Term
| how are bladder stones diagnosed? |
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Definition
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Term
| what is tx for bladder stones? |
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Definition
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