URINARY TRACT CALCULI P 1135 1141 Nephrolithiasis kidney stone disease More common in men than women except struvite stones magnesium ammonium phosphate o 20 55 years of age white 50 chance of reoccurrence ETIOLOGY AND PATHOPHYSIOLOGY Risk factors o Metabolic increased urine levels of calcium oxaluric acid uric acid or citric acid o Climate warm climates fluid loss low urine volume increased urine concentration o Diet high protein increases uric acid excretion high tea or fruit juice elevate urine oxalate level high calcium and oxalate intake low fluid intake urine concentration o Genetic family history of stones cystinuria gout renal acidosis o Lifestyle sedentary occupation immobility o More common with external urinary diversion long term indwelling catheter neurogenic bladder or urinary retention Stone formation o Supersatuerated concentration of crystals can precipitate and form stones o Mucoprotein in the kidneys serves as stone matrix o Urinary pH alkaline higher less soluble calcium and phosphate acidic higher less soluble uric acid and cysteine solute load and inhibitors Obstruction urinary stasis UTI leads to struvite stones Infected stones staghorm configuration occupy larger area of collecting system renal infection hydronephrosis and loss of kidney function TYPES Calculus stone lithiasis stone formation Five major categories o Calcium phosphate Typically mixed with oxalate or struvite Alkaline urine primary hyperparathyroidism Treat underlying cause and other stones o Calcium oxalate Small possible to get trapped in the ureter men women most common Idiopathic hypercalciuria hyperoxaluria independent oh pH family history Infrease hydration restrict oxalate in diet give cellulose phosphate prevent GI absorption potassium citrate alkaline urine choestyramine bind oxalate calcium lactate precipitate oxalate reduce sodium intake o Uric acid o Cysteine Jewish men Gout acid urine inherited condition Reduce urine acidic concentration potassium citrate allopurinol decrease purine intake Genetic autosomal recessive defect defective cysteine absorption Acid urine Increase hydration give a penicillamine and tiopronin prevent cysteine crystals potassium citrate o Strivite magnesium ammonium phosphate Women men associated with UTI large staghorn type Urinary tract infections usually proteus organisms Antimicrobial agents acetohydroxamic acid surgical intervention to remove stones acidify urine Can be mixed but calcium are the most common CLINICAL MANIFESTATIONS Cause clinical manifestations when they obstruct urinary flow UPJ ureteropelvis junction and UVJ ureterovesical junction are the most common sites for complete obstruction Abdominal flank pain hematuria and renal colic cramping o Pain can be so severe that it causes N V Pain may be absent if there is no obstruction o Type of pain determined by location of stone Calyx or UPJ dull costovertebral flank pain or renal colic Down the ureter intense and colicky May be in mild shock cool moist skin UVJ lateral flank Men testicular pain women labial pain both groin pain May have UTI like symptoms with fever and chills Objective data o Gurading back pain fever dehydration o Warm flushed sin or pallor with cool moist skin mild shock o Abdominal distention absence of bowel sounds o Oliguria hematuria tenderness passage of stones DIAGNOSTIC STUDIES Urinalysis Urine culture CT scan identify nonopaque stones from tumors IVP or retrograde pyelogram localize the degree and sire of obstruction or confirm radioucent stones uric acid or staghorn calculus NOT for people with renal failure Cystoscopy Important to retrieve and analyze stone to determine underlying cause Serum calcium phosphorus sodium potassium bicarb uric acid BUN and creatinine Ultrasound larger radiopaque stones in renal pelvis calyx or proximal ureter Urine pH Patient with recurrent stones should do 24 hour urine collection o Test amount of calcium phosphorus magnesium sodium oxalate citrate sulfate potassium uric acid and total volume COLLABORATIVE CARE Manage acute attack o Treat pain infection and obstruction o Opioids o May spontaneously pass but 4mm may need stent placement to pass Evaluate cause prevent future stones o Family history nutritional assessment geographical location activity pattern history of illnesses or dehydration and GI surgery DIET adequate hydration low sodium Struvite stone treatment requires infection treatment o Antibiotics and acetohydroxamic acid Endourologic lithotripsy or open surgical stone removal indications o Large stones o Stones associated with bacteriuria or symptomatic infection o Stones causing renal impairment o Persistent pain nausea or ileus o Inability of patient to be treated medically o Patient with one kidney Endourologic Procedures Cystoscopy removal of small stone from bladder Cystolitholapaxy larger stones stone are broken up then bladder is irrigated Cystoscopic lithotripsy ultrasonic lithotriate to pulverize stones o Complications of above 3 hemorrhage retained stone fragment and infection Ureteroscope remove stones from renal pelvis and upper urinary tract Percutaneous nephrolithotomy nephroscope inserted through sinus tract from skin to kidney pelvis stone is then fragmented and bladder is irrigated o Complications bleeding infection and damage to adjacent structions LITHOTRIPSY Not recommended for staghorn or cystine stones outcome depends on size location and composition of the stone Percutaneous ultrasonic lithotripsy ultrasonic probe in renal pelvis through the flank o General or spinal analgesia o Ultrasonic waves break up stone into sandlike particles Electrohydraulic lithotripsy positions on stone breaking it into fragments then removing them with suction or forceps o Continuous saline irrigation to get small particles o Rare complications sepsis hemorrhage abscess formation o Postoperatively moderate to severe colic pain bright red urine initially then dark red then smoky two weeks of antibiotics Laser lithotripsy probes fragment lower ureteral and large bladder stones Extracorporeal shock wave lithotripsy ESWL noninvasive o Patient is anesthetized and placed in a water bath high voltage spark generator produces high energy acoustic shock waves that shatter the stone o There are now versions that do not require submersion or high voltage energy Hematuria is normal after the procedures and a stent is usually kept in place for 2 weeks to prevent small particles from causing obstruction SURGICAL PROCEDURES