L 64 - Kidney Stones

Question 1

what is the most common type of kidney stone

what type of stone is not seen on XR?

What types of stones have ‘staghorn’ caliculi

which stone is most common is kids?

Answer 1

Calcium Oxalate / Calcium Phosphate Stones — 80% of stones

Uric Acid stones – Radiolucent

Stagorn – MAP and Cystine stones

kids – cystine

Question 2

three factors that contribute to the development of stones

Answer 2

Urinary Particle retention — low urine volume

Urinary super Saturation –

Lack of Crystal Inhibition – citrate, proteins, GAGs, HPO4 and SO4 which are negatively charged

Question 3

Signs and symptoms of renal stone

Answer 3

Abrupt onset of pain
Colicky
Unilateral to flank and radiates to groin

N/V/ Fever

Dysuria / Urgency

Hematuria

Signs: CVA tenderness

Question 4

Best imaging for a renal stone

Answer 4

CT – sensitive and specific; don’t need dye

Question 5

High risk for stone development

Answer 5

Cystinuria – cystine stones
Gout – uric acid stones

Chronic Diarrhea – IBD (which leads to hyperoxaluria)

Question 6

• The Calcium Stones:

most common type of Ca stone

most common causes

Answer 6

Calcium Oxalate

Idiopathic Hypercalciuria -

Primary HyperPTH

Question 7

Treatment of calcium stones

what drugs can be used

what is not part of the treatment regimen

Answer 7

Increase Fluid, Normal Calcium, Low Na, Low Protein Diet

Drugs:
HCTZ: (block Na/Cl co tx) incresaes Ca paracellular resorbtion

Amiloride – Enac blocker in the CCD

DO NOT RESTIRCT CALCIUM INTAKE

Question 8

• Uric Acid Stones

what processes / disease can lead to hyperuricemia

other risk factors for uric acid stones:

Answer 8

Hyperuricemia: Gout, Luekemia, Tumor Lysis, Myeloproliferative d/o

Other RF;
hot arid climates, dehydration, chronic diarrhea; acidic urine

Question 9

• Uric Acid Stones

treatment:

Answer 9

hydration, alkalinzation of the urine, allopurinol for gout

Question 10

Magnesium Ammonium Phosphate stones

• finding on imaging?
• most common cause?

Answer 10

Cause: Gram Negtaive Urease Positive Organisms – Proteus, Kelbsiella

Imaging: staghorn caliculi

Question 11

Magnesium Ammonium Phosphate stones

treatment

Answer 11

• Treatment: Surgery + Abx (prevent recurrence)

Question 12

Cysteine Stones

who gets these? 
why? 
imaging findings?
characteristic apperance of crystals 
Treatment:

Answer 12

Peds patients with cystinuria (gnetic defect of tubules that result in decrseased reabsorpitn of cysteine)

imaging: staghorn caliculi
crystals: hexagonal

Treat: hydrate and alkalinize the urine

Question 13

patient presents with ca oxalate stones and hyperoxaluria; reports h/o diarrhea

goals of treatment and evaluation

Answer 13

treatment: resolution of the current stone; prevent the next

evaluate for inflammatory bowel disease

Question 14

threshold of stone size for bypoassing medical therapies and proceeding to urologic approaches

what urologic therapies are available

Answer 14

ANY STONE < 5 mm NEEDS UROLOGIC THERPAY; NOT GOING TO PASS ON ITS OWN

Lithotripsy (mechanical, laser or ultrasonic to break up stones) 
Uretoscopy
Nephrostomy 
Laproscopy 
Electro shock wave therapy

Question 15

what is the new development n pathophys relating kidney stones to atherosclerosis

Answer 15

endothelial damage

can act as nidus for calcium oxalate stone