Urinary System Flashcards
Types of kidney stones
- Calcium oxalate
- Struvite
- Uric acid
- Cystine
Most common type of kidney stone
Calcium oxalate stones
What are some risk factors for nephrolithiasis? (6)
- Prior hx (50% recur)
- Dehydration
- Short bowel syndrome (incr. oxalate absorption)
- Grapefruit/tomato/apple juice
- Soda w/ phosphoric acid
- High salt/protein diet
What are some medications that increase risk of nephrolithiasis?
- Loop diuretics
- Anatacids
- Steroids
- Vitamin D/C
- Theophylline
- Probenacid
What are some medical conditions that increase risk of nephrolithiasis?
- Hyperparathyroidism
- Hypercalcemia of malignancy
- Sarcoidosis
Presentation of nephrolithiasis
- Renal colic
- N/V
- Diaphoresis
- Tachycardia
- Hypotension
- Urinary sx’s: dysuria, frequency, urgency
+/- CVA tenderness
What labs would you get if you suspect nephrolithiasis? What are you looking for?
- Urinalysis → hematuria, no bacteria (unless struvite), limited WBC (inflammation)
- Renal function tests
Gold standard for diagnosing nephrolithiasis? What are you looking for?
Non-contrast CT → “rim sign”, ureteral dilatation, perinephric stranding, nephromegaly
What diagnostic imaging would you use for diagnosing nephrolithiasis in pregnancy or child?
Ultrasound
Outpatient management of nephrolithiasis
- IVF
- NSAIDs (antispasmodic + antiemetic)
- Strain urine at home → bring in to office if not first stone
When would you admit pt with nephrolithiasis?
- Intractable vomiting
- Refractory pain
- Elderly, single kidney, transplant, MM, CKD, pregnant
- Acute renal failure
- Anuria
- Sepsis/fever
When is intervention indicated for kidney stone?
> 5mm
What are 3 possible interventions for kidney stone?
- Extracorporeal shock wave lithotripsy (ESWL)
- Percutaneous nephrolithotomy
- Uretoscopy + stent
When would you use ESWL for kidney stone?
If near UPJ and <2cm
When would you NOT use ESWL for kidney stone?
- Obese pt
- Cystine stones (harder)
- C/I in pregnancy, tightly impacted stone, bleeding disorder
