Hematuria / Stones - Russ Flashcards Preview

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Flashcards in Hematuria / Stones - Russ Deck (50)
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1
Q

What is the most common screening test for blood and protein in the urine?

A

Urine Dipstick

2
Q

When do false negative results occur with urine dipstick testing?

A
  • Presence of formalin
  • High urinary concentration of ascorbic acid
3
Q

When do false positive results occur with urine dipstick testing?

A
  • Alkaline urine (pH > 9.0)
  • Contamination with oxidizing agents used to clean the perineum
4
Q

How many RBCs per high power field is considered hematuria in adults? Children?

A
  • Adults = 2 RBC/HPF
  • Children = 5 RBC/HPF
5
Q

What are the four most common causes of hematuria?

A
  1. Transient unexplained
  2. UTI
  3. Stones
  4. Cancer (bladder, kidney, prostate)
6
Q

What are some less frequent causes of hematuria?

A
  • Exercise
  • Trauma
  • Endometriosis
    • cyclic hematuria
  • Sickle Cell Disease
  • Polycystic Kidney Disease
  • Glomerular Disease
7
Q

What are some risk factors for urinary tract MALIGNANCY?

A
  • Age >35
  • Smoking history
  • Occupational exposure to chemicals
  • History of:
    • gross hematuria
    • chronic cystitis
    • pelvic irradiation
    • exposure to cyclophosphamide
    • obesity
    • HTN
    • analgesic abuse
    • chronic indwelling foreign body
  • Alcohol may be protective!
8
Q

What three presentations could look like hematuria but is not hematuria because the urine supernatant is red after spinning a urine sample and the urine dipstick is negative for heme?

A
  • Porphyria
      • Phenazopyridine
    • like Azo
  • Beets
    • due to red pigment = betalaine
9
Q

What are some historical clues to the diagnosis of hematuria?

A
  • Concurrent pyuria and dysuria
    • pyuria = pus in urine
    • dysuria = painful/difficult urination
  • Recent URI
  • Family Hx of renal failure
  • Unilateral flank pain with radiation to the groin
  • Symptoms of hesitancy and dribbling
  • Vigorous exercise/trauma
10
Q

How can you tell if the hematuria is glomerular vs. extraglomerular bleeding?

A
  • Glomerular
    • red cell casts
    • proteinuria
    • dysmorphic appearing red cells
    • smokey brown or “coca cola” color
  • Extraglomerular
    • clots
11
Q

What is 50% of unexplained hematuria due to?

A

underlying glomerular disease

12
Q

Is microscopic hematuria in children worrisome?

A

NO

  • Fairly common, transient
  • 3-4% have positive dipstick for blood
    • 6-15 yoa
  • 1% have positive dipstick for blood after second UA
13
Q

What are the most common causes of persistent microscopic hematuria in children?

A
  • Glomerulopathies:
    • IgA nephropathy
    • Alport’s syndrome (Hereditary nephritis)
    • Thin basement membrane disease (Familial hematuria)
    • Post-infectious glomerulonephritis
  • Hypercalciuria
    • urine calcium/creat >2
  • Nutcracker syndrome
    • left renal vein compression by the aorta and superior mesenteric artery
14
Q

How should you evaluate microscopic hematuria in children?

A
  • Asymptomatic & isolated (no protein):
    • benign
    • just observe
  • Asymptomatic with proteinuria:
    • quantitate protein with a 1st void morning specimen for urine total protein/creatinine ratio
      • normal <0.3
    • measure serum creatinine
    • consider nephrology referral if either are abnormal
15
Q

What are some causes of symptomatic hematuria in children?

A
  • Glomerular diseases
  • Interstitial/tubular diseases
  • Lower UTI
  • Nephrolithiasis
  • Tumor
  • Vascular disease
  • Gross hematuria:
    • UTI
    • Trauma
    • Irritation of meatus or perineum
16
Q

What percentage of men will develop a symptomatic stone by age 70?

A

12%

17
Q

What percentage of women will develop a symptomatic stone by age 70?

A

5%

18
Q

Who is more likely to get a kidney stone:

Young vs. older?

Men vs. women?

White vs. Black?

A
  • Older: rate of urolithiasis increases with age
  • Men > women
  • Whites > blacks
19
Q

What are the four types of stones?

A
  • Calcium = 80% of stones
    • ***Oxalate = most common
    • Phosphate
  • Uric acid
  • Struvite
  • Cystine
20
Q

What are common symptoms of urolithiasis?

A
  • Flank pain
  • Abdominal pain
  • Testicle/Labial pain
    • waxing & waning pain
  • Gross/microscopic hematuria
  • Possible N/V, dysuria, urgency
21
Q

What are the treatment options for urolithiasis?

A
  • Pain medications
  • Hydration
  • Alpha blocker (tamsulosin) = relax ureters
  • Calcium channel blocker (nifedipine) = relax ureters
  • Ureteroscopy
  • Extracorporeal shock wave lithotripsy
  • Endoscopic lithotripsy
  • Pyelolithotomy
    • flank incision
  • Percutaneous nephrolithotomy
    • with scope using guidewire
22
Q

What kind of stones have urine sediment showing both dumbbell-shaped, envelope-shaped, and needle-shaped crystals?

A

Calcium oxalate

23
Q

What are the risk factors for calcium stone formation?

A
  • Increased calcium excretion = hypercalciuria
  • Increased uric acid excretion = hyperuricosuria
    • uric acid forms center of stone and calcium oxalate forms around
  • Reduced citrate excretion = hypocitraturia
  • Low urine volume
  • Increased oxalate excretion
24
Q

What are three possible types of Idiopathic Hypercalciuria that predispose individuals to calcium stones?

A
  • Absorptive hypercalciuria
    • autosomal dominant trait
    • increased absorption of calcium in GI → increased calcium excretion
    • elevated Calcitriol levels
  • Fasting (resorptive) hypercalciuria
    • bone loss
  • Renal hypercalciuria
    • renal leak
    • abnormal calcium reabsorption in the proximal tubule
25
Q

What are five possible etiologies for Hypocitraturia that may predispose individuals to getting calcium stones?

A
  • Chronic diarrhea
  • Renal tubular acidosis
  • Ureteral diversion
  • High protein diet
    • more acid that needs excretion
  • Topiramate
    • migraine medicine

***Any disease that causes metabolic acidosis!

26
Q

What can Hyperoxaluria be attributed to in the context of calcium oxalate stones?

A
  • Diet - 10%
  • Glycine metabolism - 40%
  • Ascorbic acid metabolism - 40%
  • Increased oxalate absorption
    • low calcium diet
    • absorptive hypercalciuria
    • enteric hyperoxaluria (malabsorption of fatty acids and bile salts)
  • Overproduction of oxalate = Primary hyperoxaluria
    • RARE
27
Q

What are three medical problems associatd with calcium stone formation?

A
  1. Primary hyperparathyroidism
  2. Medullary sponge kidney
    1. abnormality in renal papilla → more susceptible to injury → crystals latch onto damaged tissue
  3. Distal renal tubular acidosis
28
Q

What is the appropriate metabolic work-up for diagnosing why calcium stones are forming?

A
  • Plasma [Ca2+]
  • Parathyroid hormone
  • Electrolytes
    • rule out metabolic acidosis
  • Serum uric acid
  • 24 hour urine collection
    • volume
    • Ca2+, Uric Acid, Citrate, Oxalate, Creatinine, pH, Na+, PO4
29
Q

What dietary recommendations are appropriate for a patient with calcium stones?

A
  • Fluid
    • drink 2L+ of water per day
  • Restrict salt intake
  • Lower protein intake
    • protein increases citrate excretion
  • Continue Calcium intake!
    • don’t decrease dairy products → will make calcium stones worse
  • Restrict Oxalate
    • if calcium oxalate stones
30
Q

What medicinal treatments are appropriate for calcium stones?

A
  • Thiazide diuretics
  • Potassium citrate or Bicarbonate
  • Orthophosphate
  • Allopurinol/Febuxostat
    • decreases uric acid production and excretion
  • Calcium carbonate
    • take TUMS with meals
31
Q

What type of stones are non-opaque (radiolucent) on plain films, comprise 5-10% of stones in the US & Europe, but are 40% of stones in hot/arid climates?

A

Uric acid urolithiasis

(Hot/arid climates → low urine volume & acidic urine pH)

32
Q

How are uric acid stones diagnosed?

A
  • Analyze stone material recovered
  • Indirectly by demonstrating increased urine uric acid excretion
33
Q

What is the treatment for uric acid urolithiasis?

A
  • Fluids: drink >2 L per day
    • increase urine output
  • Alkalinization of urine
  • Allopurinol/Febuxostat
34
Q

What type of stones produce “coffin lid” crystals in urine sediment and only form in alkaline urine?

A

Struvite Stones

(Magnesium ammonium phosphate)

35
Q

What urine pathology are struvite stones most associated with?

A
  • UTI due to Proteus/Klebsiella (most commonly)
    • urease producing organism
      • Increased ammonia production
      • Increased urine pH
        • decreases solubility of phosphate
36
Q

What is the treatment for Struvite Stones?

A
  • Chronic administration of antibiotics
  • Acetohexemic acid
    • urease inhibitor
  • ESWL/percutaneous nephrolithotomy
    • most effective treatment
37
Q

What kind of stone produces hexagonal crystals in urine sediment?

A

Cystine Stones

38
Q

What is cystinuria?

A
  • Impairment of cystine transport leading to decreased proximal tubular re-absorption and increased cystine excretion
    • autosomal recessive trait
39
Q

How is Cystinuria characterized?

A
  • The amount of cystine excreted by the parents
    • parents usually = asymptomatic heterozygotes
40
Q

How are cystine stones diagnosed?

A
  • Family Hx
  • Hexagonal cystine crystals on urinalysis
  • Measure cystine excretion
41
Q

What is the medical treatment for cystine stones?

A
  • High fluid intake: >3 L/day
  • Alkalinization of urine: pH >7.0
  • Restrict dietary Na+
  • Drugs that attach to cystine → increase solubility
    • Penicillamine
    • Tiopronin
    • Captopril
42
Q

What are procedural treatments for cystine stones?

A
  • Irrigation of renal pelvis via catheter with penicillamine or acetylcystine
  • RESISTANT to ESWL
    • very soft stones
  • Percutaneous nephrolithotomy / ultrasonic lithotripsy
  • CURE = renal transplant
43
Q

When is medical treatment indicated for the first kidney stone?

A
  • Only in patients with metabolically active stone disease
    • formation of new stones
    • enlargement of old stones
    • passage of gravel
    • multiple stones at presentation
44
Q

What is the risk of having a symptomatic 2nd stone?

A
  • 1 year = 15%
  • 5 years = 35-40%
  • 10 years = 50%
  • Men > Women
45
Q

What is the recommended evaluation for the first kidney stone?

A
  • Limited evaluation:
    • dietary history
    • plasma calcium x2
    • consider CT scan with IV contrast
      • looking for medullary sponge kidney

Increase fluid intake → 2+L/day

46
Q

How do asymptomatic stones typically resolve?

A
  • 50% required procedure
  • 50% passed stone spontaneously

***Need to balance the risk of symptoms vs. the risk of morbidity from ESWL

47
Q

What are common complications of ESWL?

A
  • Treatment of <2 cm stones can lead to a 2-3% increased incidence of obstruction
  • Reversibly damages blood vessels and tubules
  • New onset HTN (8%)
    • presumably due to renin release form focal areas of renal ischemia
  • Impairment in renal function
    • due to scar formation
  • Residual calculi
    • (particularly with struvite stones)
48
Q

Does a complaint of red urine equate to blood in the urine?

A

NO

  • Could be caused by:
    • Beets
    • Porphyria
    • Azo
49
Q

Does painless hematuria help narrow the DDx?

A

Yes

points towards malignancy

50
Q

Does kidney function help in the DDx?

A

Yes

can differentiat between obstruction or glomerulonephropathies