SU2M - Urinary Stones and Obstructions Flashcards
7 Risk factors of Kidney stones?
- Low fluid intake
- Family history
- COnditions that precipitate stone formation = gout, Chron’s disease, hyperparathyroidism, type 1 RTA
- Medications = loop diuretics, acetazolamide, antacids, chemo drugs that cause the break down of cells (increase uric acid)
- Male gender –> 3x more likely to have urolithiasis
- UTIs –> esp w/ urease-producing bacteria
- Dietary factors = low calcium and high oxalate intake
Nephrolithiasis
development of stones within the urinary tract
4 Most common types of stones? Percentages?
- Calcium stones = 80-85%
- Uric acid stones = 10%
- Struvite = 5-10%
- Cystine stones = 1%
What are calcium stones composed of?
- Calcium oxalate –> most common
- Calcium phosphate
- Both
Which types of kidney stones are radiodense? radioluscent?
- Radiodense = calcium & struvite stones
- Radioluscent = uric acid stones & cystine
7 Causes of hypercalciuria? What can they lead to?
- ^^ intestinal absorption pf Ca
- vv renal absorption of Ca –> ^^ renal excretion of Ca
- ^^ bone reabsorption of Ca
- primary hyperparathyroidism
- sarcoidosis
- malignancy
- vitamin D excess
* *can cause calcium kidney stones
3 Causes of hyperoxaluria? What can they cause?
- Severe steatorrhea of any cause –> absorption of oxalate –> calcium oxalate stone formation
- Small bowel disease or Chron’s disease
- Pyridoxine deficiency
* *can cause calcium oxalate kidney stones
What are uric acid stones associated with?
-associated with hyperuricemia, secondary to gout or chemotx that causes an increased breakdown of cells (the dying cells release purines)
Dx of uric acid stones?
- radioLUCENT
- need to use CT, ultrasound, or IVP
4 Urease-producing bacteria? What can they cause?
- Proteu
- Klebsiella
- Serratia
- Enterobacter spp.
* *can cause struvite kidney stones
Pathogenesis of struvite stones?
- facilitated by alkaline urine
- the urea-splitting bacteria convert the urea into ammonia –> produce alkaline urine
- the ammonia combines with magnesium and phosphate –> form struvite calculi
Cause of cystine stones?
-genetic predisposition = cystinuria = autosomal recessive
Kidney stone sizes and ability to pass spontaneously?
- > 1 cm = usually do NOT pass spontaneously
- < 0.5 cm = usually pass spontaneously
Recurrence and kidney stones?
-up to 50% of patients with stone will have a recurrence within 10 yrs of having their first stone
5 Ssx of kidney stones?
- Renal colic
- description of pain: sudden, severe, occurs in waves
- location: begins in flank, radiates anteriorly to the groin (follows the path of the stone) - Nausea
- Vomiting
- Hematuira (seen in 90%)
- UTI
4 Lab tests for the diagnosis of kidney stones?
- Urinalysis –> look for:
- hematuria
- UTI
- crystals
- determine urine pH - Urine culture –> if an infection is suspected
- 24-hour urine
- Serum chemistry
Alkaline urine and kidney stones?
-can indicate an infection with urease-producing bacteria & struvite stone
Acidic urine and kidney stones?
-suggestive of uric acid stones
What does hematuria + pyuria indicate?
-stone plus and infection
Gold standard for dx of a kidney stone?
- CT scan (spiral CT) without contrast
- ALL stones (even radioluscent) will be visible
Intravenous pyelogram (IVP) and kidney stones?
- most useful test to determine the degree and extent of urinary tract obstruction
- not usually necessary for the dx of kidney stones, but can be used to determine if the pt needs procedural tx
Renal ultrasound and kidney stones?
- test of choice for pts who can’t receive radiation (ex. pregos)
- can detect hydronephrosis or hydroureter
- false-negatives are common in the early obstruction
KUB radiograph?
- Xray of the Kidneys, Ureter, & Bladder
- can be used to dx radioDENSE stones
3 General Tx for all types of kidney stones?
- Analgesia = IV morphine or parenteral NSAIDs
- Vigorous fluid hydration
- Antibiotics –> if UTI is present
