Urology

Question 1

what are the different types of kidney stones?

Answer 1

calcium stones are the most common (75% of all stones). They almost always cause symptoms when in the ureters.

staghorn calculi are the 2nd most common (15% of all stones). They are composed of calcium phosphate, ammonium & magnesium. Usually located in the renal pelvis and calyces, they are strongly a/w recurrent UTIs

uric acid stones, which are radiolucent stones only visible on non-contrast CT

cysteine stones that are relatively rare and usually have a genetic predisposition

Question 2

what are some risk factors for urolithiasis

Answer 2

dehydration or poor fluid intake
causes of high Ca
hyperparathyroidism
idiopathic hypercalciuria
disseminated malignancy
sarcoidosis
hypervitaminosis D
familial metabolic causes — cystinuria, errors of purine metabolism, hyperoxaluria, hyperuricosuria, xanthinuria
infection
impaired urine drainage —- PUJ (pelvic-ureteric junction) obstruction, ureteric stricture, extrinsic obstruction

Question 3

how would urolithiasis typically present

Answer 3

symptoms (Hx)
sudden onset + severe + stabbing + intermittent — loin to groin pain
+/- rigors, fever
+/- N&V
+/- tachycardia, palpitations
+/- macroscopic haematuria

signs (PE)
renal angle tenderness
suprapubic tenderness
pyrexia

Question 4

what Ix would u order for a suspected urolithiasis patient

Answer 4

bloods
FBC — raised WCC = ?superimposed infection
U&E —- deranged = ?renal impairment
CRP —- raised = ?superimposed infection
serum corrected Ca —- high levels = stone is calcium stone
phosphate & uric acid levels —- high = stone is staghorn stone?
+/- parathyroid hormone

urine
urine dipstick —- macroscopic haematuria
MSU C&S —- UTI
+/- 24 hr Ca & urate

imaging
x-ray KUB
non-contrast CT KUB (gold std)
renal US —- ?hydronephrosis

Question 5

if elderly + suspected renal colic = what is impt to r/o?

Answer 5

symptomatic AAA

Question 6

how would u manage a patient with a kidney stone

Answer 6

medical Tx
analgesia — NSAIDs&raquo_space;> opioids
antiemetics
hydration
alpha-blockers (eg. tamsulosin) — medical expulsive therapy

most stones <5mm = pass spontaneously over 6 wks

surgical Tx
indications
urosepsis
stone >6mm
persistent pain despite adequate analgesia
persistent obstruction
renal insufficiency
options
ESWL extracorporeal shock wave lithotripsy
endoscopic stone retrieval
PCNL percutaneous nephrolithotomy
open nephrolithotomy or ureterolithotomy

Question 7

what would you do if a patient with a kidney stone arrives with an obstruction and sepsis?

Answer 7

as this is a urological emergency, urgent decompression is needed.

this is done via percutaneous nephrostomy +/- antegrade or retrograde stenting

further intervention for definite removal of stone can be done after