Transcript Kidney_Stones

Kidney Stones
Epidemiology
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Bladder and kidney stones
detected in Egyptian mummies
dating back to 4800 BC
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Frere Jacques Beaulieu –
renowned 17th century open
stone surgeon who performed
5000 open lithotomies over 30
years
Epidemiology
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Genetic Factors
– Rare in Native Americans, Blacks, native
born Israelis
– More common among Whites and Asians
– 25% have family history
– May be result of polygenic defect with
partial penetrance (Resnick, 1968)
– RTA, cystinuria, several X-linked disorders
Epidemiology
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Age and Sex
– Peak incidence in 20’s to 40’s
– 3:1 male to female
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Higher incidence of struvite stones in females
– Equal tendency during childhood
– May have hormonal influence
Epidemiology
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Geography
– Higher prevalence in
desert, and tropical
climates
– May be related to
climate, genetic
differences within
regions
Epidemiology
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Climatic and Seasonal Factors
– Higher incidence in summer months
– Peak 1-2 months after the max mean
temperature (Prince and Scardino, 1960)
– Increased perspiration leads to increased urine
concentration
– Increased sunlight exposure leads to vitamin D,
and increased urinary calcium excretion (Parry
and Lister, 1975)
Epidemiology
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Water Intake
– Water intake versus water lost through
perspiration and respiration
– Mineral content of water consumed
– Dilutes and decreases transit time of solutes
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Occupation
– Stone disease more likely in sedentary
individuals, increased bone resorption
– Risk increased in more affluent individuals
Types of Stones
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Calcium
Uric Acid
Struvite – Magnesium Ammonium Phosphate
Cystine
Others
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Dihydroxyadenine
Xanthine
Silicate – antacid abusers
Matrix – urease-splitting organisms
Ammonium Acid Urate
Triamterene
Indinavir
Clinical Presentation
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4 points of
obstruction
– Impacted in calyx
– Ureteropelvic
junction
– Pelvic brim
– Ureterovesical
junction
Clinical Presentation
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Renal or ureteral colic
– Acute onset
– Usually begins in flank, courses laterally
around abdomen and radiates to the groin or
genital region
– Patients find it impossible to find comfortable
position
– Often nausea, emesis, ileus, diarrhea
Clinical Presentation
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Urinalysis
– Microscopic or gross hematuria
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15% without hematuria (Press and Smith, 1995)
– Moderate LE / pyuria
– May have urinary crystals
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Calcium oxalate crystals may be found if urine
allowed to sit
Radiographic Evaluation
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Plain abdominal radiograph (KUB)
– 90% radio-opaque
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Uric acid, indinavir, triamterene and matrix
radiolucent
Cystine, struvite less radiodense
Sensitivity 45-59%
Specificity 71-77%
Can be useful to guide treatment (i.e. offer ESWL)
Radiographic Evaluation
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Intravenous Pyelogram (IVP)
– Previously the study of choice
– Allows determination of obstruction, relative
function
– More time consuming
– More invasive
– Sensitivity 64-87%
– Specificity 92-94%
Radiographic Evaluation
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CT scan (non-contrast)
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Decreased time / Cost effective
No need for IV access or IV contrast
Sensitivity 95-100%
Specificity 92-94%
Does not give definitive information regarding
function, obstruction
– Secondary signs of obstruction
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Hydroureter, perinephric stranding, hydronephrosis
Radiographic Evaluation
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Ultrasound –
• can demonstrate hyperechoic focus with
posterior shadowing c/w a stone
• Overall, not a very good imaging modality
for stones.
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MRI
• Also a poor imaging modality for stones.
Management
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Hospital admission required if…
– Severe Pain, N/V not controlled by medications
– Bilateral obstruction, anuria, or ureteral stone
with a solitary kidney
– Signs of obstruction & UTI/sepsis from stone
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Elevated WBC, fevers, clinical pyelonephritis
Obstructing ureteral stones > 6 mm are less
likely to pass, may require intervention
• stent placement vs. surgical removal
Management
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Adequate Fluids / Hydration
– Increased diuresis may reduce rate of ureteral
peristalsis and inhibit stone passage?
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Anti-inflammatory agents
– OK if creatinine is normal
– Patients who received Toradol versus Demerol left
hospital earlier, better pain control (Larkin, 1999)
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Narcotics: Morphine / Dilaudid
Flomax / Uroxatral to help pass the stone
Only about 10% of patients require admission
Stone Prevention: Dietary
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Calcium Oxylate:
– Most common type of stone ( About 80%)
– Benefit from avoiding foods that are high in
oxylate (low oxylate diet)
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draft beer, certain juices and berries, certain green leafy
vegetables, coffee, tea, peanut butter, chocolate, certain nuts
Avoid high doses of Vit. C ( > 500 mg) or D
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Vit C converted to oxylate and can increase
urinary oxylate
Dietary Counseling: Calcium
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Diet should contain adequate calcium
– Moderate Ca intake, normal Ca diet (8001000 mg/day)
– Prevents calcium oxylate stones with lower GI
oxylate absorption.
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Don’t avoid calcium
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Although certain kinds of stones can be caused by excessive
calcium, overall lower incidence of stones in people who
have adequate, but not excessive amounts of calcium
compared to too little calcium in the diet
Dietary Counseling
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Fluid consumption:
– adequate to produce > 2L daily urine output
– To accomplish this, one must drink >2L
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some fluid is lost with breathing, sweating and
other normal body functions
– Supplementing the diet with lemonade
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helpful since it contains citrate which can
dissolve some crystals that form stones.
Dietary Counseling
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Excessive protein (high purine diet)
– should be avoided, especially red meats
– High protein (Atkins diet) leads to a
chronic acidosis increasing stone rate
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Low Sodium Diet
– Also recommended, generally <2g daily,
with avoidance table salt, canned foods,
processed foods, or things such as Chinese
food that may be high is sodium.
Obesity
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Higher rates of kidney stones in obese or
overweight (Multifactorial)
Sedentary lifestyle
Dietary: Purine Gluttony, excessive Na
More difficult to intervene surgically
• ESWL or PCNL
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Recommend a balanced approach with
diet, weight loss and exercise
Counseling Continued
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Initial stone episode:
– Overall, with no treatment or dietary
changes, there is about a 50% chance of
forming another stone within 5 years.
– If another stone episode does occur despite
dietary measures, I recommend a full
metabolic work-up to include blood tests and
a urorisk panel.
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CA, Mg, Phos, Uric Acid, Urorisk.
Surgical Intervention
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ESWL
– Radiodense stones <2 cm in good location
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Ureteroscopy/Stone removal
– Renal/Ureteral stones <2 cm
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PCNL
– Large Renal or proximal ureteral stones,
staghorn calculi
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Open/Laparoscopic stone removal (rare)
Questions?