Nephrolithiasis Flashcards
Describe how furosemide can cause renal stones
Increases urinary calcium excretion
True or false. Hyperparathyroidism can lead to nephrolithiasis.
True
Hyperparathyroidism increases calcium levels
For patients trying to reduce their risk of kidney stones, should they increase or decrease their dietary intake of protein?
Decrease protein intake
Urine pH in patients with struvite stones
pH>8
(infections thrive in alkaline conditions)
Treatments (4) for cystine stones
Hydration
Alkalinize urine (potassium citrate/Urocit)
Penicillamine for patients who don’t respond to conservative measures
Annual renal US or KUB
Most common type of renal stone
Calcium oxalate
As well as increasing fluid volume, drinking this can help reduce a patient’s risk of nephrolithiasis
Lemonade (or anything else containing lemon/citrate)
This type of kidney stone most commonly first presents in childhood around the age of 12
Cystine stones
Is nephrolithiasis more common in males or females?
Males
(males 19%, females 9%)
Patients with struvite stones have recurrent UTIs without e. coli but with these (3) bacteria present
Proteus (most common)
Klebsiella
Pseudomonas
Which imaging type best shows uric acid stones?
CT scan.
(Uric acid stones are radiolucent, won’t show on x-ray)
(Ultrasound used to see hydronephrosis if stone is in kidney. If stone is in ureter, won’t see on U/S)
Describe how topiramate can cause renal stones
Increases urine pH and decreases urine citrate levels
Describe a duplicated collecting system
Extra renal pelvis and/or extra ureter
Medication to help aid with passing of kidney stones by relaxing distal ureter
Alpha blockers (Tamsulosin) relax distal ureter in men and women
Three treatment methods for uric acid stones
Restrict dietary purines
Urinary alkalinization (Sodium bicarb to dissolve stones in short term, Potassium citrate long term)
Allopurinol
Dietary risk factors (7) for nephrolithiasis
Fluid intake (low)
Type of fluid (dark soda, tea)
Calcium
Protein
Oxalate
Sodium
Dietary patterns (confounds as FH)
Treatment of renal stones induced by drugs indinavir and nelfinavir require acidification or alkalinization of the urine?
Acidification
When and how to follow-up after kidney stone removal
Ensure passage of stone with imaging
Analyze stone/metabolic analysis to find cause
Follow up at six months, then annually, with KUB as recurrence rates high
Nephrolithiasis symptoms
Often asymptomatic
Abrupt onset flank pain radiating to groin or testicles
Most common renal abnormality that contributes to formation of kidney stones
Horseshoe kidney
(connected kidneys promotes urinary stasis = stone formation)
Urinary risk factors (5) for nephrolithiasis
Low urine volume (biggest one)
Hypercalciuria
Hyperoxaluria
Hypocitraturia
Urine pH
Medications (5) which can cause nephrolithiasis
Topiramate
Acetazolamide
Long term glucocorticoids
Indinavir
Triamterene
Kidney stones larger than 2cm may require this invasive procedure
Percutaneous nephrostolithotomy
Cystine stones can be diagnosed with the presence of two things in the urine. One is cystine, what’s the other?
Hexagonal crystals
This type of kidney stone runs in families in an autosomal recessive pattern
Cystine stones
This kidney abnormality causes unilateral obstruction that prevents kidney drainage
Congenital UPJ obstruction
These types of kidney stones are large and have a characteristic staghorn appearance
Struvite stones
Procedure to view and remove stones in between kidney and bladder
Ureteroscopy
May leave stent in post-stone removal to prevent ureter collapse
Kidney stones smaller than this size have an 80% chance of passing on their own
<5mm
Biggest risk factor for calcium containing kidney stones
High levels dietary oxalates
Technique using sound waves to break up large renal stones to ease passing
Lithotripsy
(aka ESWL = extracorporeal shock wave lithotripsy)
Pharmacologic therapy for calcium containing stones
Low dose thiazides (HCTZ, chlorthalidone)
Potassium citrate (increase citrate and replace K+ lost form thiazides)
Cholestyramine, Calcium carbonate (if hyperoxaluria)
Most definitive imaging for nephrolithiasis
CT abdomen/pelvis WITHOUT contrast
Area of US with highest prevalence of nephrolithiasis
South Eastern US
Name the two types of radiopaque kidney stones
Calcium containing stones (calcium oxalate and calcium phosphate)
Struvite stones
(Cystine stones are moderately radiopaque)
What is the average time to pass kidney stones sized 2-4mm?
12.2 days
(95% pass in 40 days)
