Nephrolithiasis Flashcards
What is the most common kidney stone
Calcium oxalate
List the most common causes of calcium oxalate stones
Ethylene glycol; lethal serum levels of vitamin C; hypocitraturia; Low urine PH; Malabsorption
List the most common causes of calcium phosphate crystals
High urine ph
Describe the Histologic characteristics of calcium oxalate stones
Envelope or dumbbell in shape
Describe the Histologic characteristics of calcium phosphate stones
Wedged-shaped prism crystals
Struvite stones consist of what substance
Ammonia magnesium phosphate
Describe the histologic characteristics of strubite stones
Staghorn caliculi; coffin lid shaped crystals
Struvide stones are commonly caused by what kind of UTI’s
Urease positive pathogens: proteus, Staph. saprophyticus, klebsiella; These microbials hydrolyze urea to Pneumonia which causes urine alkalization; hence the increase in ph
Uric acid stones have a strong association with what diseases
Diseases with high cell turnover rates Such as leukemias; hyperuricemia
describe the histologic features of uric acid stones
Ron Boyd and Rosette shaped crystals
What are common causes for uric acid stones
Low urine PH (below 5.5); decreased urine volume; arid climates; hyperuricosuria
Cystic stones are caused by what
Hereditary conditions leading to cysteine malabsorption in the PCT leading to cystinuria
reabsorption of wood amino acids are also affected besides cysteine
COLA:
cystine
ornithine
lysine
arginine
Histologic characteristics of cysteine stones
hexagonal shaped crystals
Patience with Cysteine stones We’ll also test positive for what
Sodium cyanide nitro presside
What are major intrinsic risk factors for development of kidney stones
urinary stasis and obstruction; renal tubular acidosis type 1; hyperparathyroidism; uti; medulary sponge kidney; Horseshoe kidney; sarcoidosis
what are major extrinsic risk factors for the development of kidney stone
dehydration; High Consumption of animal proteins; glucocorticoids (long-term usage); Carbonic and hydrates inhibitors, Laxatives, loop diuretics; Increased BMI; History of Gout; high sodium diet; excessive consumption of refined sugars; DM; For parathyroidism; decrease calcium intake; Gastrointestinal diseases
What ionic compound has a high concentration of oxalates
Sodium chloride
UTIS and kidney stones have similar clinical manifestations; except patients with kidney stones also can experience pain to what region besides the flank
colicky painradiating to groin
A medulary sponge kidney is associated with what kind of stones
Calcium stones
Large stones in the renal pelvis are usually indicative of what kind of kidney stones
Struvite
Wood stones are radiopaque and can therefore be seen on an x-ray
calcium, strobite, cysteine
nephrocalcinosis Is commonly associated with what type of Kidney stones
More commonly calcium phosphate less commonly calcium oxalate
What kind of stones are radiolucent and cannot be seen on a x-ray
Uric acid stones
Radio lucent stones are also associated with what drugs
protease inhibitors, xanthine, dihydroxyadenine
Where do kidney stones commonly cause obstruction
Junction between the renal pelvis and ureter; Crossing of the ureter over iliac blood vessels; Entrance of the ureter into the bladder also called the Urito Vesicle Junction
Where is the gold standard for kidney stone diagnosis
Non contrast CT
Will a kidney stone that is five millimeters in diameter pass spontaneously without medical or pharmacologic intervention
yes
Pharmacologic therapy is usually not implemented unless the stone is greater than what parameter
greater than five millimeters but less than ten millimeters; A stone greater than 10 Millimeters Will have to be removed by A urologist To avoid further damage to the kidneys And long term complications
what is the first line pharmacologic agent to facilitate the passing of the kidney stone
Alpha blockers
calcium kidney stones can be treated with what pharmacologic agent
thiazides
prophylaxis of calcium & cystine stones can be mediated by what lifestyle modification
Low sodium diet
Calcium phosphate stones can specifically be treated with what agent
Citrate
What pharmacologic agents can be used to treat uric acid stones
carbonic and hydrates inhibitors and allopurinol (alkalinization of urine)
chelating agents such as tiopronin & penicillamine can be used in refractory cases of what stone type
cystine stones
What is the mechanism of action for citrate
Forms complexes with calcium to lower urine calcium saturation
Besides citrate what are other common stone inhibitors
Urea, magnesium, glyco amino glycans, pyrophosphate; All reduce ionic activity and the formation of crystal complexes
What are emergent indications for surgical removal of a stone
Obstructing stones with a active uti; bilateral kidney stones with acute kidney injury; Unilateral obstruction with acute kidney injury and those that only have one functional kidney; All other scenarios are elective indications
Summary
make sure to do the review questions on the Nephrolophiasis ppt
