Everything's
How do conditions, such as leukemia, increase patient risk for uric acid stones?
What is...
increased uric acid release from cells
How does low levels are citrate lead to kidney stone formation?
What is...
citrate typically binds calcium → decreased citrate → increased free calcium → stone formation
The other team believes vaccines will give you autism(even though they already have autism??)
What is...
yay:D
A 38-year-old man presents with intermittent left flank pain for the past week. He has a history of recurrent nephrolithiasis and consumes a diet high in sodium and animal protein.
Urinalysis: pH 6.8, envelope-shaped and rosette-shaped crystals.
CT (non-contrast): 6 mm hyperdense stone at the left ureteropelvic junction.
KUB X-ray: radiopaque calculus.
What treatment plan do you suggest?
What is...
thiazide
low sodium diet
hydration
A 32-year-old woman presents with right-sided flank pain and fever for 3 days. She reports dysuria and cloudy, foul-smelling urine. Temperature 101.8 °F (38.8 °C). CVA tenderness is present on the right.
Urinalysis shows: pH 8.5, positive leukocyte esterase and nitrites, and numerous “coffin-lid” crystals.
Non-contrast CT reveals a large branching calculus occupying the right renal pelvis and calyces. KUB X-ray shows a radiopaque, staghorn-shaped stone.
What is the most likely cause of the patients stone formation?
What is...
infection wit urease-producing bacteria
Urease → urea → ammonia + CO₂ → alkaline urine → precipitation of magnesium ammonium phosphate → staghorn calculi
What type of CT should be used to visualize a kidney stone and why?
What is...
non contrast because contrast makes structures bright/white and kidney stones are bright/white so they would blend in
Organize the pH precipitation table
What is...
Precipitate at low pH = calcium oxalate, cystine, uric acid
Precipitate at high pH = struvite, calcium phosphate
MOA of allopurinol
what is...
inhibits xanthine oxidase → decrease uric acid formation
A 14-year-old girl is evaluated for recurrent kidney stones. Her older brother has had similar problems.
Urinalysis: pH 5.0, hexagonal crystals.
Non-contrast CT: multiple small bilateral renal calculi.
Cyanide-nitroprusside test is positive.
What is the pathophysiology of this patient’s condition?
What is...
Defective reabsorption of dibasic amino acids in the proximal tubule
Cystinuria = defective transporter for Cystine, Ornithine, Lysine, and Arginine (COLA) → cystine stones form in acidic urine. Autosomal recessive inheritance
A 45-year-old man presents with sudden, severe left flank pain radiating to the groin, accompanied by nausea. He follows a high-protein, low-carbohydrate diet.
Urinalysis: pH 5.5, numerous “envelope-shaped” crystals, no WBCs or bacteria.
Non-contrast CT shows a 5 mm hyperdense stone in the left ureter with mild hydronephrosis. KUB X-ray shows a radiopaque stone in the left ureter.
What is most likely the composition of the patient's stone?
What is...
calcium oxalate stone
What is primary hyperoxaluria?
What is...
autosomal recessive metabolic disorder characterized by excessive production of oxalate
Type 2 (PH2): Caused by a deficiency of the enzyme glyoxylate reductase/hydroxypyruvate reductase (GRHPR)
Type 3 (PH3): Caused by a mutation in the gene AGXT2, which encodes an enzyme involved in oxalate metabolism
What does a high specific gravity indicate and how does it apply to our case?
What is...
high solute concentration in urine → higher concentration → stones are more likely precipitate
Why does a low sodium diet a preventative treatment?
What is...
low sodium diet activates RAAS which indirectly increases calcium reabsorption → calcium removed from urine → decrease chance of stone formation
A 60-year-old man with non-Hodgkin lymphoma develops severe flank pain after starting chemotherapy.
Urinalysis: pH 5.0, numerous rhomboid-shaped crystals.
CT (non-contrast): small hyperdense calculus in right ureter.
X-ray: no visible stone.
Serum uric acid: markedly elevated.
What is an initial preventive measure for this patient’s condition?
What is...
allopurinol or urine alkalinization
A 29-year-old woman with primary hyperparathyroidism presents with intermittent right flank pain.
Urinalysis: pH 7.8, needle-shaped “rosette” crystals, no bacteria.
Non-contrast CT reveals a 4 mm calcified stone in the right renal calyx; X-ray shows a radiopaque calculus.
What most likely contributed to this patient’s stone formation?
What is...
Increased urinary calcium excretion due to hyperparathyroidism
Primary hyperparathyroidism → ↑ PTH → ↑ bone resorption and ↑ serum/urinary calcium → calcium phosphate stones in alkaline urine
MOA of thiazide
What is...
block the sodium-chloride cotransporter in the distal tubule → lower intracellular sodium concentration → sodium-calcium antiporter → increase calcium reabsorption
Why shouldn't calcium intake be reduced?
What is...
decreased calcium increases free oxalate → stone formation
Compare and contrast when to order a CT vs. ultrasound
What is...
CT unless you want to limit exposure to radiation
A 46-year-old man with Crohn disease presents with left flank pain radiating to the groin.
Urinalysis: pH 5.2, envelope-shaped crystals.
CT (non-contrast): 4 mm stone in distal left ureter.
KUB X-ray: radiopaque stone.
What mechanism most likely caused this patient’s condition?
What is...
Fat malabsorption → calcium binds fat instead of oxalate → ↑ free oxalate absorption → calcium oxalate stone formation
A 33-year-old man is found confused and tachypneic after being discovered next to an empty antifreeze bottle.
Labs show severe metabolic acidosis with an increased anion gap.
Urinalysis: pH 5.3, numerous envelope-shaped crystals.
CT: bilateral small renal calculi.
KUB X-ray: radiopaque stones.
What is the most likely mechanism of stone formation?
What is...
Precipitation of calcium oxalate due to excess oxalate metabolism
Ethylene glycol → metabolized to oxalic acid → binds calcium → calcium oxalate stones, metabolic acidosis, and renal failure
10 seconds to match the stone to it's crystal!
What is...
Struvite = rectangular prism/coffin
Calcium oxalate = dumbell/envelope
Calcium phosphate = wedge shape
Cystine = hexagon
Uric acid = rhomboid/rosette
For 3 minutes, let's discuss some strategies to obtain past medical history from patients, especially children, who struggle to verbalize due to autism spectrum disorder
What is...
wahooooo
Describe the proteus mirabilis sketchy
What is...
Mermaid man = swarming motility
NH3 spray bottle = urease positive
Stone = struvite kidney stone
Antlers = staghorn calculi
Fish = fishy odor
Eggs = sulfamides
Bathroom = UTI
A 44-year-old man presents to the emergency department with severe left-sided flank pain radiating to the groin. He just completed a weeklong hiking trip in a desert environment and admits to poor fluid intake.
Urinalysis: pH 5.0, numerous rhomboid crystals.
Non-contrast CT: 3 mm calculus in the left distal ureter.
KUB X-ray: no visible stones.
What is most likely the composition of the patient’s stone?
What is...
Uric acid
Dehydration → concentrated, acidic urine → uric acid precipitation. Uric acid stones are radiolucent on X-ray but visible on CT
A 56-year-old man undergoing chemotherapy for lymphoma presents with right flank pain radiating to the groin. He reports dark, concentrated urine.
Urinalysis: pH 5.0, yellow-brown rhomboid crystals.
Non-contrast CT: hyperdense calculus in the distal right ureter. KUB X-ray: no visible stone.
Why this patient’s stone is not seen on plain radiography?
What is...
Uric acid stones are radiolucent because they lack calcium