SM_216a: Kidney Stones Flashcards
Describe the epidemiology of kidney stones
Epidemiology of kidney stones
- Common
- Higher prevalence in men
- Many have recurrence
- Higher risk in Asians and Caucasians, stone belt in U.S.
Pathogenesis of kidney stones is related to the chemical property _____
Pathogenesis of kidney stones is related to the chemical property solubility
- Determined by concentration of ions/compound, pH, and temperature
Describe the pathogenesis of kidney stones
Pathogenesis of kidney stones
- Concentration of substance exceeds solubility threshold
- Supersaturation
- Precipitation out of solution
- Crystal formation
Crystal formation of kidney stones occurs more quickly when _____
Crystal formation of kidney stones occurs more quickly when other solid particles exist in solution on which precipitation can occur (stone nidus)
Acidic urine pH promotes formation of ____ and ____ kidney stones
Acidic pH promotes formation of cystine and uric acid kidney stones
Basic urine pH promotes formation of ____ and ____ containing kidney stones
Basic urine pH promotes formation of Ca and P containing kidney stones
____ are the most common kidney stone in the U.S.
Calcium-containing stones are the most common kidney stone in the U.S.
Calcium containing stones include _____ and _____
Calcium containing stones include calcium oxalate and calcium phosphate
Calcium oxalate stones resemble _____
Calcium oxalate stones resemble square envelopes
Risk factors for calcium stones are _____ and _____
Risk factors for calcium stones are hypercalcuria and hyperoxaluria
Describe how causes of hypercalcuria are a risk factor for calcium stones
Hypercalcuria as a risk factor for calcium stones
- Secondary to hypercalcemia: increased serum Ca levels -> increased urinary Ca
- Idiopathic: serum Ca normal but urinary Ca elevated
Describe how causes of hyperoxaluria are a risk factor for calcium stones
Hyperoxaluria as a risk factor for calcium stones
- Dietary intake of high oxalate foods
- Vitamin C intake: ascorbic acid metabolized to oxalate
- Malabsorption in GI tract: leads to increased oxalate reabsorption
- Low calcium intake: less Ca to bind oxalate -> more systemic oxalate absorption -> increased urinary oxalate
- Primary hyperoxalosis
Struvite kidney stones result from _____ and are composed of _____ and _____
Struvite kidney stones result from infection and are composed of magnesium ammonium phosphate and calcium carbonate apatite (triple phosphate)
Struvite kidney stones resemble _____
Struvite kidney stones resemble coffin lids
Describe the pathogenesis of struvite kidney stones
Pathogenesis of struvite kidney stones
- Urease-producing bacteria, such as Proteus, alkalinize the urine
- Urinary phosphate becomes insoluble
- Urinary phosphate complexes with surrounding ions (Mg, Ca, NH4+)