1.17 + 18 urolithiasis Flashcards

Question

describe briefly the features of Cystine stone..

Answer 1

Yellow to brown Hexagonal smooth hard (ts'she said) Faintly radiopaque

Answer 2

- Hereditary (AR) - cystine reabsorbing-PCT-transporter loses function resulting in: 1. cystinuria (is poorly soluble) --> stones form in urine 2. poor reabsorption of: ->irnithine ->lysine ->arginien (COLA) - Usually begins in childhood - Can form staghorn calculi - Positive sodium cyanide nitroprusside test -th: ->low Na diet ->alkalinization of urine ->chelating agents (eg. penicillamine) if refractory

Answer 3

Smooth Coffin lid soft lightly colored rapidly growing into staghorn calculi slightly radiopaque

Answer 4

- Caused by infection with urease +'s: --> P.mirabilis --> S. saprophyticus --> Klebsiella that hydrolyze urea->amonia-> urine alkalinization - Commonly form staghorn calculi - th: -->eradication of underlying infection -->surgical removal of stone

Answer 5

Asymptomatic (when stone in renal collecting system) ureteric stones -->obstruction which leads to: ->colic pain (localized to the tip of the penis) ->hydronephrosis pain -> Hematuria ->AKI (obstructive) ->nfection -> obstructive pyelonephritis

Answer 6

- US: ->mainly for renal stones ->stones appear echogenic with shadows behind - plain Xray - IV pyelography, retrograde pyrography ->stones creates filling defect -Low-dose CT (gold-std) info about: -> size ->location ->HU value >1000 is considered hard stone ->HU <800 is considered soft stone which is more susceptible to ESWL treatment (Extracorporeal shock wave lithotripsy) -Consider renal function tests (BUN/Cr)

Answer 7

Conservative approach Extracorporeal shock wave lithotripsy (ESWL) Percutaneous nephrolithotomy: Retrograde uretero-renoscopy Open surgery Management of obstructive pyelonephritis

Answer 8

consider if patient is mildly symptomatic and stone is small: - Pain control (NSAIDs, opioids) - Spasmolytics (drotaverine) - Phytotherapy (induces ureter peristalsis) - beta-blockers (if small stone in the lower part of the ureter)

Answer 9

- xtracorporeal shock wave lithotripsy - US shock wave creates pressure differences between surface and core of the stone --> stone is crashed into smaller fragments - Effective for treating kidney stones <2 cm in diameter, as long as no obstruction to the passage of stone fragments is present.

Answer 10

- for Stones >2 cm in diameter - Under fluoroscopic control, a track with a diameter of ~1cm is introduced into the collecting system - Disintegrating devices (US-based), which can be introduced through a nephroscope, are used to break the stone into fragments that can be evacuated

Answer 11

- Laser fiber is introduced through a flexible guide wire, which is introduced through the urethra and bladder, up the ureter to the renal collecting system - Stones < 1 cm in diameter can be disintegrated - Use a Dormia basket or forceps to collect stone fragments

Answer 12

- Not frequently indicated - Staghorn stones, in which the bulk of the stone lies within calices rather than within the renal pelvis, are treated best by open surgery. - Kidneys that contribute < 10% of overall renal function should usually be removed

Answer 13

->Antibiotics ->antipyretics ->fluids -> Urine deviation (nephrostomy or Double-J stent) -> Stone removal

Answer 14

-Up to 50% of patients who produce their first stone will have a recurrence within 10 years. - we Consider analysis of stone composition - determine further metabolic changes that can have beneficial effect on reducing the risk of stone reoccurrence: ->increase fluid intake (aim for >2L/day urine output) ->Thiazide diuretics (for idiopathic hypercalciuria) -> decrease uric acid lvls (lifestyle changes, allopurinol) -> AB to eradicate any urinary tract infection -> Low-sodium diet, low-protein diet, low-purine diet

Answer 15

--> ethylene glycol (antifreeze) ingestion --> VitC abuse --> hypocitraturia associated with decreased urine ph (eg. Crohn disease)

1.17 + 18 urolithiasis Flashcards

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