Kidney stones Flashcards
Kidney stones can lead to severe complications such as
- hydronephrosis
- pyelonephritis
- SCC
Kidney stones - symptoms
- unilateral flank tenderness
- colicky pain
- pain radiating to groin
- hematuria (no casts)
Kidney stones - treat and prevent
encourage fluid intake
MC kidney stone presentation
calcium oxalate stone in patient with hypercalcemia or normocalcemia
Calcium stones MC (80%) –> calcium oxalate more common than calcium phosphate
Kidney stones - contain
- Caclium (calcium oxalate, caclicum phosphate)
- Ammonium magnesium phosphate
- Uric acid
- Cystine
kidney Caclium stones - types
- calcium oxalate
2. calcium phosphate
calcium oxalate vs calcium phosphate according to precipitation
calcium oxalate –> low pH
calcium phosphate –> high pH
calcium oxalate vs calcium phosphate according to x-ray findings
calcium oxalate –> radiopaque
calcium phosphate –> radiopaque
calcium oxalate vs calcium phosphate according to CT findings
calcium oxalate –> radiopaque
calcium phosphate –> radiopaque
calcium oxalate vs calcium phosphate according to urine crystals
calcium oxalate –> shape like envelope or dumbbell
calcium phosphate –> wedge-shaped prism
Calcium oxalate stones are precipitated by (beside low ph)
- ethylene glycol (antifreeze) ingestion
- vitamin C abuse
- malabsorption (Crohn disease)
- hypocitraturia –> low ph
kidney calcium stone treatment
calcium oxalate –> thiazides, citrate, low-sodium diet
calcium phosphate –> thiazides
Ammonium magnesium phosphate stones are precipitated by
high ph
Ammonium magnesium phosphate stones on CT and on X-ray
Radiopaque in both
Ammonium magnesium phosphate stones - urine cristal
coffin lid
Ammonium magnesium phosphate stones are AKA
sturvite
Ammonium magnesium phosphate stones (sturvite) (frequency)
15% of stones
Ammonium magnesium phosphate stone (sturvite) are caused by
infection with urease + bugs (eg. Proteus mirabilis, Staphylococcus saprophyticus, Klebsiella) that hydrolize urea to ammonia –> urina alkalization
Ammonium magnesium phosphate stone (sturvite) commonly form
staghorn calculi
staghorn calculi is a
large stone that takes up more than one branch of the collecting system in the renal pelvis of the kidney.
Ammonium magnesium phosphate stones (sturvite) - treatment
- eradication of underling infection
2. surgical removal of stone
Urease + organisms
- proteus
- cryptococcus
- H. pyloru
- Ureoplasma
- Nocardia
- Klebsiella
- S. epidermidis
- S. saprophiticus
Uric acid stones are precipitates in
low ph
Uric acid stones on CT and on X-ray
X-ray –> radiolucent
CT –> minimally visible
BUT VISIBLE ON US
Uric acid stones - urine crystals
rhomboid or rosettes
Uric acid stones - frequency
5% of all stones
Uric acid stones - visible on
US
Uric acid stones - risk factors
- low urine volume
- arid climates
- acidic ph
- strong association with hyperuricemia
Uric acid stones - strong association with
hyperuricemia
Uric acid stones often seen in disease with
high turn over (eg. leukemia)
Uric acid stones - treatment
- urine alkalization
2. allopurinol
Cystine stones are precipitated by
low ph
Cystine stones on X-ray and CT
X-ray –> radiolucent
CT –> visible
Cystine stones - urine crystal
hexagonal
causes of Cystine stones
Hereditary (AR) condition in which Cystine -reabsorbing PCT transporter loses function causing cysteinuria (also poor reabsorption of ornithine, lysine, arginine) –> cystine is poorly soluble, thus stones form in urine
(mneomnic: COLA: Cystine, Ornithine, Lysine, Arginine)
Cystine stones - age
usually begins in childhood
Cystine stones can form
staghorn calculi
Cystine stones - diagnosis
(+) sodium cyanide nitroprusside test
Cystine stones - treatment
- low sodium diet
- alkalinization of urine
- chelating agents if refractory
kidney stones - types/precipitating factors/x-ray/CT
- calcium oxalate –> low ph, radiopaque in both
- caclicum phosphate –> high ph, radiopaque in both
- Ammonium magnesium phosphate, high ph, radiopaque in both
- Uric acid –> low ph, radiolucent in x-ray, minimally vissible in CT
- Cystine –> low ph, radiolucent in xray, sometimes vissuble in CT
kidney stones - types and urine crystals
- Calcium oxalate –> shaped like envelope or dumbbell
- Caclicum phosphate –> wedge-shaped prism
- Ammonium magnesium phosphate –> coffin lid
- Uric acid –> Rhomboid or rosettes
- Cystine –> hexagonal
Urinary incontinence - types
- Stress incontinence
- Urgency incontinence
- Mixed incontinence
- Overflow incontinence
urinary Stress incontinence - mechanism
Outlet incompetence (urethral hypermodility or intrinsic sphincteric deficiency –> leak with high intra-abdominal pressure (eg. sneezing, lifting)
urinary Stress incontinence - increased risk with
obesity
vaginal delivery
prostate surgery
urinary Stress incontinence - diagnosis
(+) bladder stress test –> directly observed leakage from urethral upon coughing or Valsvava maneuver)
urinary Stress incontinence - treatment
- pelvic floor muscle strengthening (Kegel) exercise
- weight loss
- pessaries ( a plastic device inserted into the vagina)
urinary Urgency incontinence - mechanism
Overactive bladder (detrusor instability) –> leak with urge to void immediately
urinary Urgency incontinence - treatment
- pelvic floor muscle strengthening (Kegel) exercise
- bladder training (timed voiding, distraction and relaxation techniques)
- antimuscarinics
urinary Mixed incontinence - mechanism
features of both stress and urgency incontinence
Overflow incontinence - mechanism
incomplete emptying (detrusor underactivity - weak to emoty the bladder or outlet obstruction) –> leak with overfilling –> increased postvoid residual (urinary retention) on cathetirization or ultrasound
Overflow incontinence - treatment
catherterization relieve obstruction (α-blockers for BPH)