Urinary stones, formation

Karagiille, O., U. Smorag, F. Candir, G. Gundermann, U. Jonas, A.J. Becker, A. Gehrke, and C. Gutenbrunner. Clinical Study on the Effect of Mineral Waters Containing Bicarbonate on the Risk of Urinary Stone Formation in Patients with Multiple Episodes of CaOx-Urolithiasis. World Journal of Urology 25, no. 3 (June 2007) 315-23. 

Penicillamine forms stable, soluble complexes with copper, iron, mercury, lead, and other heavy metals that are excreted in urine it is particularly useful in chelating copper in patients with Wilson s disease. Penicillamine also combines with cystine alone, reducing free cystine below the level of urinary stone formation. 

Hofbauer, J., Steffan, I., Hobarth, K., Vujicic, G., Schwetz, H., Reich, G. and Zechner, O. (1991). Trace elements and urinary stone formation New aspects of the pathological mechanism of urinary stone formation. J. Urol. 145,93-96. 

Cranberry concentrate tablets taken for 7 days were shown in one study to significantly increase urinary oxalate levels and urinary calcium, phosphate, and sodium along with magnesium and potassium, both inhibitors of urinary stone formation (Terris et al. 2001). The study has been criticized for methodological flaws such as failing to measure... 

Beging, S., Mlynek, D., Hataihimakul, S., Poghossian, A., Baldsiefen, G., Busch, H., Laube, N., Kletnen, L., Schoning, M.J., 2010. Field-effect calcium sensor for the determination of the risk of urinary stone formation. Sensors Actuators B 144, 374—379. 

Maintaining Adequate Fluid Intake and Output Because one adverse reaction of the sulfonamide dragp is altered elimination patterns, it is important that the nurse helps the patient maintain adequate fluid intake and output. The nurse can encourage patients to increase fluid intake to 2000 mL or more a day to prevent crystal-luria and stone formation in the genitourinary tract, as well as to aid in the removal of microorganisms from the urinary tract. It is important to measure and record the intake and output every 8 hours and notify the primary health care provider if the urinary output decreases or the patient fails to increase his or her oral intake... 

DRUGS USED FOR GOUT. The nurse encourages a liberal fluid intake and measures the intake and output. The daily urine output should be at least 2 liters. An increase in urinary output is necessary to excrete the urates (uric acid) and prevent urate acid stone formation in the genitourinary tract. 

Increased fluid intake increases urinary output, lowering substance concentration involved in stone formation. Hydration is recommended to reduce new stone formation. 

The presence of Ca in kidney stones and the abnormally high Ca levels in idiopathic (absorptive) hypercalciuric individuals that are inherently more prone to kidney stones, initially led to the belief that dietary Ca may be a cause of renal stone formation (Coe et al., 1992). Recent evidence suggests that, as a therapeutic approach to reducing the risk for kidney stones, Ca-restricted diets may pose a greater risk to normocalciuric individuals prone to kidney stone formation such an approach may increase urinary oxalate and the likelihood of recurrent stones, as well as promote bone loss (Borghi et ah, 2002 Coe et al., 1997 Curhan et ah, 1997). The amoimt of oxalate excreted in urine has been foimd to be positively associated with Ca oxalate supersaturation and stone formation (Holmes et ah, 2001). While free oxalic acid is readily absorbed from the gut lumen (Morozumi et ah, 2006), an increased dietary Ca to oxalate... 

Mechanism of Action An antacid that reduces gastric acid by binding with phosphate in the intestine, and then is excreted as aluminum carbonate in feces. Aluminum carbonate may increase the absorption of calcium due to decreased serum phosphate levels. The drug also has astringent and adsorbent properties. Therapeutic Effect Neutralizes or increases gastric pH reduces phosphates in urine, preventing formation of phosphate urinary stones reduces serum phosphate levels decreases fluidity of stools. 

Calcium and magnesium homeostasis is altered by chronic diuretic therapy. Loop diuretics increase the urinary excretion of Ca2+ and can lead to stone formation. Thiazide administration, on the other hand, has the opposite effect and causes frank hypercalcaemia in some patients. Both thiazide and loop drugs increase the urinary loss of Mg2+ and this has been associated with cardiac arrythmias in the elderly. 

H6. Harris, H., and Warren, F. L., Quantitative studies on urinary cystine in patients with cystine stone formation and their relatives. Ann. Eugenics 18, 125-171 (1953). 

Stone formation may occur in those with elevated levels of urinary calcium, Mormally adults excrctc less than 200 mg of calcium in the urine per day, even with relatively high intakes of calcium, A fraction of the population absorbs more calcium than normal and excretes more calcium in the urine, resulting in hyper-calciuria. Hypercalciuria is defined as urinary excretion of calcium of more than 300 mg/day. About half of patients with calcium stones have hypercalciuria and may be calcium hyper absorbers. Persons with hypercalciuria are advised to limit their calcium intake to one serving of milk or cheese per day. They are also advised to limit their protein intake to the RDA. Their protein intake should be limited to minimize the caiciuric effect of protein. They are also advised to fnerense their water intake to produce 2 liters of urine per day and to avoid oxalate-containing foods. Persons with hypercalciuria and with a familial history of stones should not lake calcium supplements to raise their intake above the RDA. 

Vaccinium macrocarpon (cranberry, marsh apple) has been used to prevent and treat urinary tract infections, although it is not useful in established infections (10,11). It is supposed to act by preventing adhesion of bacteria to the bladder wall. It may also reduce the risk of formation of some types of urinary stone (12,13). 

McHarg T, Rodgers A, Charlton K. Influence of cranberry juice on the urinary risk factors for calcium oxalate kidney stone formation. BJU Int 2003 92(7) 765-8. 

Viscosity of THP solutions increases markedly when the sodium chloride concentration is > 60 mM. Increasing the concentration of calcium and/.or a reduction in pH also increase viscosity and may account for the involvement of THP in the pathogenesis of cast nephropathy and tubulointerstitial nephritis. THP appears to have an inhibitory effect on urinary crystal arrgegation [154] and may play a role in preventing renal stone formation [155]. In some humans with calcium oxalate nephrolithiasis, a molecular abnormality of THP has been detected [156]. Other studies showed decreased urinary levels of THP in patients with nephrolithiasis [157, 158]. A relative deficiency in THP has been associated with impaired inhibition of crystal adhesion to renal epithelial cells instone formers [159]. 

Diuretics have been shown to have variable effects in relationship to urinary calcium excretion and supersaturation, most notably including loop diuretic induced hypercalciuria and attenuation of urinary calcium excretion by thiazide diuretics. The factors contributing to nephrotoxicity are most commonly associated with multiple factors that favor calcium salt or uric acid deposition at the tubulo-interstitial level. Management of renal stone formation and nephrocalcinosis therefore presents a unique clinical challenge, balancing factors that increase risk for abnormal calcium salt deposition or crystallization, and factors that reduce this risk. 

Flesse A, Fleimbach D Causes of phosphate stone formation and the importance of metaphylaxis by urinary acidification A review. World J Urol 1999 17 308-315. 

Robertson WG. The effect of high animal protein uptake on the risk of calcium stone formation In the urinary tract. Clln.Scl. 1979 57(3) 285-8. 

Cranberry juice has been widely used for the prevention, treatment, and symptomatic relief of urinary tract infections (3). Also, cranberry juice has been given to patients to help reduce urinary odors in incontinence (4-6). Another potential benefit of the use of cranberry is a decrease in the rates of kidney stone formation (7-9). 

Kidney Stones. About one in five patients with clinical gout also has urinary tract uric acid stones. Although plasma and urinary uric acid should he measured in stone formers, many uric acid stone formers do not demonstrate either hyperuricuria or hyperuricemia. However, this may reflect the use of reference intervals derived in a purine-rich, westernized society.The etiology of uric acid stone formation also involves the passage of a persistently acid urine with loss... 

Other secretory products of the nephron are not weU understood. For example, a significant proportion of normal urinary protein is formed by Tamm Horsfall glycoprotein (THG). This protein is secreted by the distal tubule and is thought to play a role in inhibiting kidney stone formation, but this has not been confirmed conclusively. The tubular epithelial cells also synthesize a vast range of growth factors and cytokines in response to a variety of stimuli that can have both autocrine and paracrine effects. All cells also secrete a range of cell adhesion molecules that are essential to cellular attachment to the tubular basement membrane. 

The milder ( classic, type III) Bartter s syndrome is due to defects in tire basolateral pump CLC-Kb. Although the phenotype is extremely variable (neonatal, life-threatening presentations do occur), these patients typically present in the first year of hfe with weakness and hypovolemia and normal urinary calcium excretion. Nephrocalcinosis and kidney stone formation are not normally features. 

Following treatment and successful removal of a stone, follow-up monitoring is required, as many patients wiU have recurrent disease in the absence of medical treatment the recurrence rate may be as high as 50% at 10 years. The mechanisms responsible for the multiple recurrences of kidney stones in only certain individuals are not completely understood. Factors involved include (1) urine flow (fluid intake) (2) excretion of excess quantities of stone components (3) the relative absence of a substance, or substances, in the urine that inhibit stone formation and (4) urinary pH (see Figure 45-16). The predominant risk factor is poor hydration, a concentrated urine increasing the concentrations of the mineral salts hirther, predisposing to crystallization. This at least partially explains the increased incidence of kidney stone disease in hot climates, for example, in the Gulf states. 

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